A coronavirus vaccine might not be ready until later next year, the former deputy chief medical officer for England has said.
Professor Gina Radford said people needed to be "realistic" about the prospect of a vaccine as researchers are having to "start from scratch" to create one.
Foreign Secretary Dominic Raab also said a vaccine was unlikely to "come into play" until the end of this year.
It comes as the first human trials for a Covid-19 vaccine in the UK began on Thursday at the University of Oxford.
Prof Radford, who held her government role between 2015 and 2019, was asked on Sky News' Sophy Ridge On Sunday show about the prospect of a vaccine.
She said: "We haven't got a hugely good track record with vaccines for this particular virus, coronavirus, the family of viruses.
"But having said that, everything is being thrown at it. There are researchers all over the world trying to identify a vaccine.
"We have never seen anything like the effort that is being made to discover this vaccine."
Prof Radford said there is a "huge process" of testing that needs to be undertaken to determine if potential vaccines are safe and effective.
"There is no point creating a vaccine that will then cause more harm than it is trying to prevent," she added.
"I think those who are very used to the process of developing vaccines are saying they are not anticipating it being available until well into next year."
Prof Radford said that while the vaccine could be created sooner as the Government is "fast-tracking" its development, it would still have to be manufactured in a large capacity.
Meanwhile, Mr Raab told BBC1's The Andrew Marr Show on Sunday that the Government was "pursuing" vaccines and testing "at pace".
He said: "But the vaccine wouldn't realistically come into play until the end of the year - the testing, tracking and tracing I think has a better medium-term prognosis."
Human trials on a potential vaccine saw the first two volunteers in the UK injected by researchers at the University of Oxford on Thursday.
Both participants - a scientist and a cancer researcher - said they wanted to help in what could be a groundbreaking development in the fight against the disease.
The Oxford Vaccine Group was hoping to repeat the process with six more volunteers on Saturday, moving to larger numbers on Monday.
Up to 1,102 participants will be recruited across multiple study sites in Oxford, Southampton, London and Bristol.
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Prime Minister Jacinda Ardern speaks at a briefing on the coronavirus pandemic at Parliament on Monday in Wellington, New Zealand. Pool/Getty Images hide caption
Prime Minister Jacinda Ardern speaks at a briefing on the coronavirus pandemic at Parliament on Monday in Wellington, New Zealand.
New Zealand's Prime Minister Jacinda Ardern says that the island nation has defeated for the present the coronavirus as her government announced the lifting of most restrictions imposed to halt the spread of COVID-19.
"There is no widespread undetected community transmission in New Zealand. We have won that battle," Ardern said Monday. "But we must remain vigilant if we are to keep it that way."
Asked if New Zealand had eliminated COVID-19, Ardern replied: "currently."
Coronavirus in New Zealand has been trending down since April 5, when 89 confirmed cases were announced. On Sunday, there were no new cases announced for the first time in weeks, but another five were reported on Monday. A total of 19 people have died in New Zealand from COVID-19.
The country's director-general of health, Ashley Bloomfield, said the small number of new cases in recent days "does give us confidence that we have achieved our goal of elimination."
Bloomfield and Ardern said that declaring the virus eliminated did not mean there would be no new cases, but that the numbers would be manageable with the help of aggressive contact tracing, which the prime minister said had been scaled up "significantly" with the capacity to make up to 10,000 calls per day.
Ardern's remarks came as New Zealand, a country of just 5 million people, downgraded its COVID-19 alert to level 3 meaning most, but not all, businesses are being allowed to reopen.
Businesses and professions that require face-to-face contact, such as hairdressers, sales people, masseuses and public gyms will remain closed until the alert level is reduced another notch, Ardern said.
"Your business must be contact-less. Your customers can pay online, over the phone or in a contact-less way," she said. "Delivery or pick-up must also be contact-less."
Exceptions include supermarkets, dairies, gas stations, pharmacies or other permitted health services, according to the New Zealand Herald.
For those who do return to the physical workplace, they should maintain 1 meter (about 3 feet) of social distancing, Ardern said.
"COVID-19 has spread in workplaces, so the quid pro quo of being able to open is doing it in a way that doesn't spread the virus," she said.
The prime minister also advised that if people can work from home, they should continue to do so.
New Zealand has garnered praise for largely putting aside politics in order to tackle the outbreak.
As NPR's Julie McCarthy reports, Ardern, 39, a mother of a 21-month-old, "regularly appears on Facebook Live chats, dressed in a sweatshirt, commiserating with families enduring isolation in their 'bubble,' as she calls their place of shelter, and assuring children the tooth fairy is still on the job. When she imposed stringent stay-home rules in late March, she urged people to 'be strong and be kind.' "
Like New Zealand, Australia has also seen a precipitous decline in new cases since a peak nearly a month ago.
Speaking on Sunday, Australia's home affairs minister, Peter Dutton, suggested that New Zealand and Australia could reopen travel between them even as restrictions on inbound air passengers from other countries remained.
"You could look at an arrangement with New Zealand given they're at a comparable stage as we are in the fight against this virus," Dutton told Sky News, as reported by Radio New Zealand. "You could look at other nations in our region if they've enjoyed the same success, but New Zealand might be the natural partner."
Coronavirus antibody test kits are key to plans for proposed "immunity passports," but the World Health Organization is warning that such cards may simply encourage further transmission. Greg Baker/AFP via Getty Images hide caption
Coronavirus antibody test kits are key to plans for proposed "immunity passports," but the World Health Organization is warning that such cards may simply encourage further transmission.
The World Health Organization has pushed back against the theory that individuals can only catch the coronavirus once, as well as proposals for reopening society that are based on this supposed immunity.
In a scientific brief dated Friday, the United Nations agency said the idea that one-time infection can lead to immunity remains unproven and is thus unreliable as a foundation for the next phase of the world's response to the pandemic.
"Some governments have suggested that the detection of antibodies to the SARS-CoV-2, the virus that causes COVID-19, could serve as the basis for an 'immunity passport' or 'risk-free certificate' that would enable individuals to travel or to return to work assuming that they are protected against re-infection," the WHO wrote. "There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection."
The statement comes days after Chile announced it would begin issuing immunity cards that effectively act as passports, allowing travelers to clear security at airports with a document that purportedly shows they have recovered from the virus. Authorities and researchers in other countries such as France and the United Kingdom have expressed interest in similar ideas, while some officials in the U.S., such as Los Angeles Mayor Eric Garcetti, have mentioned it as one possible facet of a reopening strategy.
The concept for such a card is largely based on the premise that an individual can only contract the coronavirus once before developing the necessary antibodies to fight it off. That premise undergirds another common theory: the concept, known as herd immunity, that if enough people have been infected with the coronavirus and are therefore immune its transmission will slow and the risks of infection will diminish even for those who haven't caught it yet.
But these ideas depend to a large degree on the supposition that one cannot catch the coronavirus a second time an idea that world health authorities said leaders should not count on right now. As of Friday, the WHO said, "No study has evaluated whether the presence of antibodies to SARS-CoV-2 confers immunity to subsequent infection by this virus in humans."
What's more, data reported from the world's early COVID-19 hot spots, such as South Korea and China, have shown that a growing number of recovered patients appear to have suffered a relapse of the disease.
By mid-April, Korean health authorities said that just over 2% of the country's recovered patients were in isolation again after testing positive a second time. And in Wuhan, China, data from several quarantine facilities in the city, which house patients for observation after their discharge from hospitals, show that about 5% to 10% of patients pronounced "recovered" have tested positive again.
It remains unclear why this is occurring whether it is a sign of a second infection, a reactivation of the remaining virus in the body or the result of an inaccurate antibody test.
Dozens of antibody tests for the novel coronavirus are already on the market, with varying degrees of reliability and accuracy. House Democrats have launched an investigation into the antibody tests and whether the Food and Drug Administration should increase its enforcement of them, according to CNN.
"At this point in the pandemic, there is not enough evidence about the effectiveness of antibody-mediated immunity to guarantee the accuracy of an 'immunity passport' or 'risk-free certificate,' " the WHO warned.
"People who assume that they are immune to a second infection because they have received a positive test result may ignore public health advice. The use of such certificates may therefore increase the risks of continued transmission."
Groups of scientists around the world are using wastewater testing as a non-invasive way to measure the prevalence of coronavirus in their communities.
Local governments in the US are also turning to the tests, which detect traces of coronavirus genetic material -- known as RNA -- in fecal matter.
The data can be used to gain a sense of how many people may have had the virus asymptomatically and are passing it through, in addition to those testing positive because they are outwardly sick, New Castle County Executive Matt Meyer told CNN.
"We're confident as we do this weekly, now that we're working with Biobot, that this can give a varying indication of the total number of cases in our county, which is somewhat useful," Meyer said. "We want to identify hotspots, run this at 10 treatment facilities across a county of 560,000 people, and find out with these hotspots where they are and where they're not."
Meyer said he has spoken with state officials about implementing wastewater testing across the state -- though he said he's been met with some skepticism.
"I think it's fair there's skepticism, to be honest," Meyer said. "What (Biobot is) doing seems really smart. The science seems sound. There are uncertainties everywhere ... I hope this works and we've got to be skeptical."
'Early warning system'
Meanwhile, in the Syracuse area of New York, four professors across three universities have partnered up to test Onondaga County wastewater using a centrifugal process to isolate the virus -- a process they say could significantly speed up detection of Covid-19 outbreaks.
David Larsen, a public health professor at Syracuse University, told CNN he organized the project after coming across a paper showing that scientists in the Netherlands had successfully performed a wastewater test for Covid-19.
Larsen said he recruited his colleague Teng Zeng in Syracuse's engineering department to collaborate with wastewater facilities in Onondaga County. Samples were then sent to Hyatt Green and Frank Middleton, both of whom are part of the State University of New York (SUNY) system.
Middleton, a professor at SUNY Upstate Medical University, said the isolation process they have devised adheres RNA samples of Covid-19 in wastewater to polyethylene glycol, a resin that destroys the active virus and concentrates into a pellet.
The pellet is then tested through a process known as polymerase chain reaction (PCR). The PCR is used to detect Covid-19 specifically, as opposed to other viruses that may have found their way into the testing samples, Middleton said.
He estimated that in the group's academic lab, they could test up to 100 samples a day, though if there were enough samples provided, PCR could perform as many as 1,500 tests daily.
"This is unlike anything that I've done in the past," Middleton, who serves as the director of the SUNY Molecular Analysis Core, said. "We can do that PCR almost instantaneously, after we have the pellet. About 12 minutes later -- by lab standards, it's almost instantaneous -- (we have the results)."
Green, a microbiologist at the SUNY College of Environmental Science and Forestry, said the entire testing process would most likely take close to four to eight hours because of what's entailed in actually collecting and filtering out the wastewater samples.
But he said the difference in hours of testing for Covid-19 presence regularly -- compared to testing only symptomatic patients when there are spikes in cases -- could be a major deterrent in reducing hotspots both now and in a potential second wave.
"In some areas, it's not practical," Green said. "But in a lot of areas, it is. If you have surveillance set up ahead of time and can crank it up at the beginning when you first hear about the possibility of an outbreak, you can use the platform as an early warning system. That would give us days or weeks lead time in coping with the pandemic or epidemic."
Testing overseas
Scientists in other countries have also been using their sewerage systems to mass test for Covid-19, though they express caution on how accurately wastewater samples reflect community levels of the virus.
"A small percentage of patients with Covid-19 have the novel coronavirus in their gastrointestinal tract, and thus excrete it in their faeces," the institute said in a statement, issued on March 24.
The wastewater testing approach had previously been used to detect viruses such as polio and measles, the statement said.
The Italian Institute for Health (ISS) reported last week that wastewater samples had returned positive results for parts of Milan and Rome. It said the RNA that was detected did not necessarily represent live, infectious virus.
"The result reinforces the prospects of using urban center sewage control as a non-invasive tool for early detection of infections in the population," the ISS said in a statement. "In Phase 2, surveillance can be used to indirectly monitor the circulation of the virus and to early detect its possible reappearance, thus allowing to recognize and circumscribe any new epidemic outbreaks more quickly."
Australian researchers have also found traces of the virus in sewage and said they are working towards a national testing program.
In neighboring New Zealand, scientists at the state-owned ESR said they are testing wastewater for Covid-19 to try to gauge the effectiveness of eradication efforts and better understand the patterns of community transmission.
But the ESR researchers noted that Covid-19 was a respiratory illness and "unlikely to be spread by contaminated faeces," suggesting levels of the virus would be low and hard to detect.
CNN's Livia Borghese and Sharon Braithwaite also contributed to this report.
NASHVILLE, Tenn. (WATE) Cases of coronavirus in Tennessee were up 5% in one day or 478 cases to 9,667 on Sunday as the state moves forward with reopening its economy.
Deaths were up 2% or 3 people to 181, according to figures released by the Tennessee Department of Health. Deaths are mainly happening to people who get COVID-19 and are 61 years old or older. The 61 and older group accounts for 152 of the 181 deaths, or 84%.
Men are nearly 61% of the deaths. Black or African Americans make up about 17% of the states population, but 31.5% of the COVID-19 deaths.
There have been 828 hospitalizations due to coronavirus and 4,527 have recovered from the virus. Tennessee has tested 147,475 people.
An increase in cases has been expected because of increased testing efforts by both the state Department of Health and county health departments.
Davidson and Shelby counties have had more than 2,200 cases each.
Gov. Bill Lee announced Fridaymore details about his plan to reopen the state, starting with the 89 non-metro counties. Most state parks opened for day-use on Friday. His safer-at-home order expires Thursday.
The states metro counties are taking a slower approach to reopening. Knox County and Knoxville are set toannounce plans on Monday
The governors plan has faced some pushback. The governor has adopted a laissez-faire approach to re-opening: no enforcement, no detailed requirements, and limited industry-specific direction, beyond restaurants and retail, state Sen. Jeff Yarbro, a Nashville Democrat, said Friday.
We want to see things get back to normal as much as you do, Dr. Aaron Milstone, a pulmonologist and organizer of a group of health care workers that has urged for a stay-at-home order, said in a news release. Many of us doctors are small business owners ourselves; many of us have spouses, family and friends hurting because they have lost their job or seen their work hours cut.
But, we cannot address the economic crisis without first solving the health crisis that created it. To solve this crisis we need Gov. Lee, our members of Congress and Senators Marsha Blackburn and Lamar Alexander to do their jobs so that we can do ours.
The Tennessee Supreme Court on Friday issued an order to extend the judicial state of emergency until May 31.
The order allows local judicial districts to develop a strategy to begin holding more in-person court proceedings in their districts.
Jury trials will remain suspended until July 3, unless there are extraordinary circumstances.
Lee and state Health Commissioner Dr. Lisa Piercey will be on a statewide televised town hall on Thursday that will air at 7:30 p.m. on WATE-TV and WATE.com
The COVID-19 case count for Tennessee is now 9,667 as of April 26, 2020, including 181 deaths, 828 hospitalizations and 4,527 recovered. For more information, go to: https://t.co/Pwof6IANuV. Questions or need assistance? Call the Public Information Line at (833) 556-2476. pic.twitter.com/jIO4KDE1Tc
Drive-thru COVID-19 testing increases Monday in Lexington. The states partnership with Kroger is opening a site at BCTC.
It looks like right now were about at the top of our curve, said Dr. Ryan Stanton from Baptist Health Lexington.
Dr. Stanton explained that testing had been limited until this point. We were testing high-risk patients, those that end up in emergency departments those with significant symptoms, those are the hospitals.
Increased drive-thru services make testing more available to people with mild symptoms, and some sites (like the states partnership with Kroger) are even available to people without symptoms at all. Of course with increased testing, we expect the number of confirmed cases to rise. Dr. Stanton says people shouldnt be worried about that. In fact, the data could prove that Kentuckys death rate is actually lower than what it seems.
I think that number is actually going to drop significantly with widespread testing, especially now that were doing asymptomatic patients because were going to start to see those folks that really may not have even known that they had it to begin with, he said.
When it comes to reopening businesses, Dr. Stanton believes some can start... but slowly. People still need to be mindful of social distancing so we dont create another wave.
I think thats going to be a long term threat until there is a vaccine available, he warned.
**Appointments for testing at the BCTC site have been filled for the first week. More will be available May 4-8.
Starting Friday, April 24:The former Rite Aid location at 2296 Executive Drive(at the corner of Winchester Road & Executive Drive)Will be operating 9am to 5pm, seven days a weekEligibility: Health care workers, first responders with or without symptoms, or anyone 18 and over with symptomsSign up: walgreens.com/coronavirus
Starting Monday, April 27:BCTC Campus at 500 Newtown PikeWill be a Monday-Friday operation8:30am-5:30pmEligibility: open to everyone This is the state site thats a partnership with KrogerSign up: thelittleclinic.com/drivethru-testing
The Covid-19 coronavirus meets its most formidable foe the moment it enters the human body.
The immune system is waiting, ready for action, and it determines who dies and who survives. It is why the vast majority of the infected have recovered from the disease.
Yet one of the most important unknowns is why some peoples immune systems are up to the task of clearing out the virus while others are sluggish or overreact, leading to death. Just as vexing:
Its helpful in thinking through these unanswered questions to understand how the immune system works (collectively and in individuals), how immunity testing works, and how immunity to similar viruses changes over time. Its also comforting to know that if you get Covid-19, your body will try very, very hard to save you. And if it doesnt, it could be because it tried too hard.
So here is a guide to the immune system: antibodies, serological tests, reinfection, and immunological memory, explained.
The first thing to know about the immune system is that it is not simple. At all.
A huge array of cells and chemicals your body produces work in concert to clear a foreign invader from your body. Theres a lot of elegance to this whole system, Akiko Iwasaki, an immunologist at the Yale School of Medicine, says. Its like an orchestra. All these cells and chemicals have to work in concert each with a different part to play to defeat the virus.
A viral infection begins when a virus enters a cell of your body. In the case of Covid-19, which is transmitted mostly by respiratory droplets, maybe that takes place somewhere in the lining of your nose or in the area of your lungs directly in contact with the air you inhale.
The virus then attaches to a cell via a protein on the cells surface called ACE-2 and lets itself in.
There, it begins to wreak havoc. The virus hijacks the cells machinery to make copies of itself. Those copies break out of the cell and then spread around your body. The copies enter more of your cells, make more copies, and so on. This is going viral, in the literal sense, and its a process your body works furiously to stop.
If the immune system is an orchestra in concert, its music can be broken down into two movements.
First, the opening: the innate immune response. This is the base-level protection you have to defend against infections even those your body has never seen before.
Iwasaki explains that every cell of your body has something of its own immune system in miniature. Your cells have a mechanism to detect virus infection, she says. Every cell is looking out for telltale genetic signs of viral replication. Once thats found, your cells start secreting these cytokines [signaling molecules] to tell the neighboring cells that theres a viral infection, she says. It will signal that cell to make a lot of antiviral proteins. Every part of the viral life cycle is targeted by hundreds of genes that are induced by this.
The innate immune response will then try to stop the virus in its tracks there, but it can fail, as we know. Viruses those sneaky bastards have evolved ways to counter this initial response. The viruses might encode proteins that degrade some of these signaling molecules, Iwasaki says. Even though we have this amazing system, viruses try to circumvent it.
If the innate immune system cant get rid of the infection, the second movement in this orchestration begins: the adaptive immune system. It has a vast array of instruments, each tuned to a specific task.
There are dendritic cells, which act as messengers from the innate immune system and tell the adaptive immune system which viral proteins it should seek out and destroy. There are killer T-cells, which hunt down and kill cells that have been infected. There are helper T-cells, which stimulate killer T-cells and recruit yet another class of cells called macrophages to gobble up infected cells, and they also stimulate B-cells, which bring this whole concert to a crescendo.
B-cells are critically important because they produce antibodies. These are little proteins that bind, specifically, to a single distinct part of a virus or pathogen and make it unable to hijack your cells. Antibodies can also identify invaders for other immune cells to destroy, and they can mark infected cells for destruction before a virus can burst out. And after an infection fades, the antibodies that linger can prevent the same virus from rising again.
But this process takes time.
When you first get infected with SARS-Cov-2, it usually takes anywhere from 10 to 14 days to make antibodies that are effective, says Vineet Menachery, an immunologist who studies coronaviruses at the University of Texas Medical Branch. That immunity actually peaks between four and eight weeks after youve been infected. The antibodies are really powerful at that point.
It takes a long time because an antibody has to be unique for the virus its trying to protect against. It takes a while and some trial and error to both build an antibody that can perfectly bind to the contours of the virus and to produce millions of copies of that antibody. The magnitude of potential antibodies is somewhere in the neighborhood of quadrillions or quintillions, Angela Rasmussen, a Columbia University virologist, says. But your immune system can narrow the choices down to the right formulation to clear the virus from your body.
The process isnt simple, but you can be in awe of it, like you can be in awe of a timepiece constructed from hundreds of delicately selected parts. I teach an entire semester course on this, Iwasaki says. This is the delicate process that a vaccine is trying to replicate artificially.
This antibody construction process can backfire, however. In some cases, antibodies bind to the virus, Iwasaki explains, and instead of blocking the virus, theyre taken up by white blood cells. Those white blood cells then go haywire, producing molecules called cytokines. Ordinarily, these chemicals promote inflammation throughout the body.
Inflammation is something that makes us feel sick, but it also helps us survive. People often think of swelling when they think of inflammation, Rasmussen says. Swelling occurs because cells from your immune system are rushing into the site of the infection. These immune cells have to get out of your blood vessels, she says, in order to corral the infection. Its a lovely process called rolling extravasation, she says. Your tissue gets inflamed because the balance of fluid is being changed.
But sometimes, so many cytokines are released that they trigger white blood cells to turn against healthy cells. That can then lead to organ failure and death. And that ultimately makes the disease as bad as it is, Iwasaki says.
Its unclear why a cytokine storm, as this reaction is called, might impact some people severely and not others, though there are indications that aging is a factor, as are underlying conditions like high blood pressure and diabetes. Researchers are also now looking for genetic clues to see who is most at risk. Thankfully, though, doctors do have some insights into how to treat this overreaction.
This whole orchestra ends when the immune system neutralizes all the virus in the body. That doesnt always mean the virus is purged; many viruses can linger in a latent state in the body without reproducing or causing symptoms. These latent viruses can flare up when the immune system is weakened, causing opportunistic infections. At the same time, youll be left with antibodies circulating in your blood.
But for reasons scientists dont quite understand, for some infections and notably, in other types of coronavirus infections antibody levels can wane over a period of years.
So how do doctors and scientists know if this process has been successful? How can they know if someone is now immune to the virus that causes Covid-19?
They test for it.
In particular, blood tests, also known as immunity tests or serological tests, can reveal who possesses antibodies to the virus. Deploying these tests will help answer a lot of questions. Most basically, it can help a person know if they have had Covid-19.
On a larger scale if deployed in well-designed studies serological tests could reveal the complete picture of the pandemic. They can also help scientists answer basic questions like:
Serological tests could also potentially allow people who have immunity to return to work. That could be a huge boost to front-line health workers who may have been exposed to the virus but are desperately needed back in action.
Just finding the antibodies isnt always enough, though. Scientists also need to do additional tests to make sure those antibodies are potent.
There are two main types of antibody tests, Menachery explains. The first just looks for antibodies and can be completed in a few hours. This is called an ELISA test (short for Enzyme Linked Immunosorbent Assay). And it doesnt provide the most complete picture of immunity.
The second test is more involved, and rarer. Its called a serum neutralization test, and it takes a few days to process. It not only looks for antibodies, it then exposes those antibodies to a virus in a cell culture to see how effective the antibodies are in stopping the virus.
Ideally, scientists will correlate the two tests and figure out which concentrations of antibodies confer the highest level of immunity. This work is ongoing, Menachery says. Its still not known what levels of antibodies are needed to have lasting, protective immunity. (What also remains to be shown: that the presence of antibodies also means you cant give the virus to someone else.)
These tests are useful, but they dont answer everything. As noted earlier, it takes days, if not weeks, for the body to produce antibodies. So a negative antibody test doesnt mean the virus isnt present. And since antibodies are produced during an infection and linger after its cleared, a positive antibody test doesnt mean that the virus is no longer active.
Confirming whether someone can still spread Covid-19 requires a separate genetic test like an RT-PCR test that detects the active virus.
Even if people do become immune, one thing we dont know about still is how long that immunity would last, Rasmussen says. And thats unfortunately not something we can determine until we wait months or years in the future, and test again and see if those antibodies are still there.
For reasons scientists dont quite understand, for some infections, your immunity never wanes. People who are immune to smallpox, for example, are immune for life: Antibodies that protect against smallpox have been found as long as 88 years after a vaccination.
Less reassuring here is that scientists have observed antibody levels to other coronaviruses (there are four coronavirus strains that infect people as the common cold) can wane over a period of years. A few weeks after an infection, antibody levels will be at their highest. But a year from now, that number is likely going to be a little bit lower, and five years from now its likely to be potentially a lot lower or a little bit lower, and we dont know the factors that change that, Menachery says.
However, even if you lose the antibodies, it doesnt mean you are again completely susceptible to the virus. Yes, none of this is simple.
There have been a few experiments where volunteers were willingly exposed to a coronavirus strain that produces a common cold. These studies show its common for the antibodies to these other coronavirus strains to decline after a year or so.
The majority of people that dont have serum neutralizing antibodies [i.e., antibodies that take out the virus], they get infected again, but they didnt get that sick, Menachery says. You couldnt do this type of test for Covid-19, he adds; its too dangerous.
There have been reports of a few patients out of China who had mild symptoms of Covid-19 who did not have detectable neutralizing antibodies after recovery, though they did have another form of antibody that binds to the virus. Its unclear whether they have protective immunity, Nature reports. Yes, there is more than one type of antibody, and they do different things, because none of this is simple.
Luckily, even if your antibodies against a coronavirus decline, your body has a backup plan.
Certain types of B-cells recall, these are the ones that make antibodies become memory B-cells. These save the instructions for producing a particular antibody, but they arent active. Instead, they hide out in your spleen, in your lymph nodes, perhaps at the original site of your infection waiting for a signal to start producing antibodies again.
With the memory B-cells in reserve, instead of waiting two weeks or more to get antibody production going, youll only have to wait maybe two or three days, Menachery says. So that means, yes, you can get infected again, but you may not even know youre sick. If you do get sick, maybe its a very minor infection.
Generally, he says, the more severe your infection, the more antibodies your immune system will produce, and the longer theyll stay in your bloodstream post-infection. So, he says, there is some concern that if you had a mild infection that your level of protection may not last long.
You may have seen some reports of people testing positive a second time for Covid-19 after recovering. The experts we spoke to say these reports are likely due to flaws in testing. I think the risk of being infected more than once from SARS-CoV-2 is nil, says Gregory Gray, an infectious disease epidemiologist at Duke University, in an email.
That may be because as you progress in the illness, the testing for Covid-19 becomes more inconsistent.
Often at the time that virus diseases present themselves, its fairly far into the replication of that virus in that person, says Diane Griffin, a professor of microbiology and immunology at the Bloomberg School of Public Health at Johns Hopkins University. Many symptoms of virus disease are actually manifestations of the immune response to the disease. Often things are starting to get better at the time youre starting to figure out someone even has a virus infection.
At least in the short term, its probably more the case that the people who have tested positive after recovering havent completely cleared the virus from their system or that a prior negative test was inaccurate.
Over the long term, the immune system itself becomes less effective with advancing age. And as people get older, they can acquire more chronic illnesses that can hamper the response to a virus, even if its one the immune system recognizes. It will be years, though, before scientists can understand what aging means for immunity to Covid-19.
The Centers for Disease Control and Prevention is now conducting serological surveys for Covid-19 antibodies in several places across the US.
Its an attempt to figure out who was previously infected with the virus, particularly if they never exhibited symptoms. A survey like this can show the actual background rate of infection and answer critical questions like what proportion of people have been infected without showing symptoms and where the virus has spread in a population, and quantify the overall rates of severe complications. Knowing these variables can help health officials better target interventions.
Many people who may have been infected also want to know if they are immune so they can safely leave lockdowns. Countries like Germany are even considering granting immunity passports so individuals can return to work.
Such testing could make a difference in a handful of cases, like for doctors and nurses who were infected or may have been exposed but are desperately needed back in action. But serological testing is unlikely to be a wholesale solution to reopening the economy.
Again, scientists are still uncertain about the robustness and duration of immunity that a Covid-19 infection confers, so a positive antibody test at this point doesnt guarantee that one can safely end social distancing measures. If immunity does fade after a year or two, the same person could be vulnerable to reinfection.
Meanwhile, to reopen schools, shops, and offices across the board, large numbers of people would have to have immunity. Without a vaccine, that would mean that the virus would have to infect vast swaths of the population, in the process sending thousands to the hospital and to their graves. That is exactly what measures like lockdowns and social distancing are trying to avoid.
While this outbreak has been ghastly, it has not been so bad as to bring about herd immunity in any quick time frame. There have been some imperfect serological studies that suggest the virus has infected more people than previously estimated. But even if true, the studies dont mean were anywhere close to achieving herd immunity.
So its unlikely that immunity can be a benchmark for when its okay to go back to normal across the population, and even in individual cases, it requires careful consideration of risks and benefits.
For those who have not yet contracted the virus, the main form of protection from Covid-19 right now is prevention. But there are several options scientists are studying that could help those who were never infected fend off the illness.
Chief among them is a vaccine. A vaccine can take various forms, including a weakened version of the virus itself, a small piece of the virus, or genetic material that prompts the immune system to manufacture antibodies to the virus.
Developing a vaccine for SARS-CoV-2 would be the ideal solution to the Covid-19 pandemic since its a form of prevention that would also hasten the end of costly measures like lockdowns, quarantines, and social distancing.
But its a time-consuming approach. Many experts estimate that it will take at least a year to develop a vaccine for the new coronavirus.
Vaccines can also pose risks. A small number of people can have dangerous adverse reactions to a vaccine, like severe allergies. In rare cases, vaccines can cause a phenomenon called immune enhancement, where the vaccine makes the recipients immune system overreact to the virus target, leading to a more severe disease than in those who were unvaccinated.
Though these risks are small, vaccines have to be delivered to millions of people. Thats why vaccine development focuses so much on safety and reducing the risks of complications as much as possible. Researchers are looking into various ways to speed up development, including human challenge trials where volunteers are deliberately exposed to the virus to test their immunity with and without a vaccine.
Another tactic under investigation is using convalescent plasma. The idea is to harvest the liquid part of blood, including proteins used for clotting, from people who have survived Covid-19. This plasma contains antibodies to the virus, so scientists are seeing whether it can help people with active infections get better. Researchers are also studying whether convalescent plasma can be used as a prophylactic to prevent Covid-19 in the first place.
Companies are also developing antibodies to SARS-CoV-2 using mice genetically engineered to have human immune systems. These antibodies can also be used to treat or prevent the disease.
But antibody transfusions, whether they come from Covid-19 survivors or were created in a lab, only confer protection against the virus for a few months.
The long-term strategy is to get enough people in a population immune to the virus so that it no longer spreads easily. This is known as herd immunity. It usually requires between 70 and 90 percent of a group of people to be immune in order to be effective, depending on the contagiousness of the virus.
With a large enough share of immunity in the population, even the remaining people who are not immune face a much lower likelihood of being infected. With few susceptible hosts in close proximity, pockets of infection quickly fade out. The question is whether this herd immunity is attained through vaccination or through infection.
The latter would not be ideal since it would involve millions getting sick from Covid-19. The United Kingdom was pursuing this approach back in early March but backed off its herd immunity strategy of limiting restrictions on movement and allowing people to be exposed. The country changed course when forecasters revealed that millions would likely contract the virus, overwhelming the UKs health system. Sweden has adopted a similar approach and is now facing vastly more Covid-19 cases than its neighbors.
Its also hard to gauge how close any country is to herd immunity since many people have likely been infected with the virus without knowing it. Figuring this out would require extensive testing for antibodies. And not everyone develops the same level of immunity from an infection. So vaccinating people against Covid-19 is the safer strategy.
Until then, widespread testing to identify the infected, isolating them, and tracing their contacts could help ease some of the pandemic control measures in place now.
How about what we can do as individuals?
Short of drugs like interferons, there isnt much a person can do to boost their immune system or their response to Covid-19, despite what various supplements promise.
The best Covid-19 approach for individuals is healthy habits maintain good hygiene, exercise, eat a balanced diet, get plenty of sleep, stay hydrated, manage any chronic health conditions like diabetes, and limit exposure to pollution.
Though the Covid-19 pandemic has been raging for several months, a lack of key information from how many people were infected to the origins of the disease continues to hamper the response.
More science on almost every aspect of this new virus is needed, but in this pandemic, as with previous ones, decisions with great consequences must be made before definitive data are in, wrote Harvard epidemiologist Marc Lipsitch in a column in the New York Times.
But the unknowns around immunity to the disease may be the most critical because they stand between the untenable present and a return to normal. Meanwhile, pressure is mounting to relax restrictions on movement to allow life to continue. With incomplete information, policymakers still have to make decisions that depend on immunity, but this can be done in ways that reduce risk.
The best approach is to construct a conceptual model a set of assumptions about how immunity might work based on current knowledge of the immune system and information about related viruses, and then identify how each aspect of that model might be wrong, how one would know and what the implications would be, Lipsitch wrote.
This is no easy task. It still might be the case that what we learn about immunity may not be enough for everything to go back to normal. We may need to wait, patiently, for a vaccine.
One advantage scientists have in the Covid-19 pandemic that they didnt have in prior outbreaks is an unparalleled level of information-sharing among researchers around the world. Researchers are posting their preliminary findings online for the world to scrutinize and working across borders, collaborating on an unprecedented scale.
That has led to unknowns becoming known faster than ever. But the disease is continuing to spread, and the drastic pandemic response measures cant continue forever, so some difficult choices lie ahead.
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Forgetting for a moment that this is coming from the same guy who famously explained in 2011 why software is eating the world, Andreessen, an icon of Silicon Valley, does have a point. As George Packer has written in the Atlantic, the coronavirus pandemic has revealed much of what isbroken and decayed in politics and societyin America. Our inability to make the medicines and stuff that we desperately need, like personal protective gear and critical care supplies, is a deadly example.
Silicon Valley and big tech in general have been lame in responding to the crisis. Sure, they have given us Zoom to keep the fortunate among us working and Netflix to keep us sane; Amazon is a savior these days for those avoiding stores; iPads are in hot demand and Instacart is helping to keep many self-isolating people fed. But the pandemic has also revealed the limitations and impotence of the worlds richest companies (and, we have been told, the most innovative place on earth) in the face of the public health crisis.
Big tech doesnt build anything. Its not likely to give us vaccines or diagnostic tests. We dont even seem to know how to make a cotton swab. Those hoping the US could turn its dominant tech industry into a dynamo of innovation against the pandemic will be disappointed.
Its not a new complaint. A decade ago, in the aftermath of what we once called the great recession, Andrew Grove, a Silicon Valley giant from earlier era, wrote a piece in Bloomberg BusinessWeekdecrying the loss of Americas manufacturing prowess. He described how Silicon Valley was built by engineers intent on scaling up their inventions; the mythical moment of creation in the garage, as technology goes from prototype to mass production. Grove said those who argued that we should let tired old companies that do commodity manufacturing die were wrong: scaling up and mass-producing products means building factories and hiring thousands of workers.
But Grove wasnt just worried about the lost jobs as production of iPhones and microchips went overseas. He wrote: Losing the ability to scale will ultimately damage our capacity to innovate.
The pandemic has made clear this festering problem: the US is no longer very good at coming up with new ideas and technologies relevant to our most basic needs. Were great at devising shiny, mainly software-driven bling that makes our lives more convenient in many ways. But were far less accomplished at reinventing health care, rethinking education, making food production and distribution more efficient, and, in general, turning our technical know-how loose on the largest sectors of the economy.
Economists like to measure technological innovation as productivity growththe impact of new stuff and new ideas on expanding the economy and making us richer. Over the last two decades, those numbers for the US have been dismal. Even as Silicon Valley and the high-tech industries boomed, productivity growth slowed.
The last decade has been particularly disappointing, says John Van Reenen, an MIT economist whohas recently written about the problem(pdf). He argues that innovation is the only way for an advanced country like the US to grow over the long run. Theres plenty of debate over the reasons behind sluggish productivity growthbut, Van Reenen says, theres also ample evidence that a lack of business- and government-funded R&D is a big factor.
His analysis is particularly relevant because as the US begins to recover from the covid-19 pandemic and restart businesses, we will be desperate for ways to create high-wage jobs and fuel economic growth. Even before the pandemic, Van Reenen proposed a massive pool of R&D resources that are invested in areas where market failures are the most substantial, such as climate change. Already,manyare renewing calls for a green stimulus andgreater investments in badly needed infrastructure.
So yes, lets build! But as we do, lets keep in mind one of the most important failures revealed by covid-19: our diminished ability to innovate in areas that truly count, like health care and climate change. The pandemic could be the wake-up call the country needs to begin to address those problems.
ROCHESTER, Minn. COVID-19 took the lives of 28 other Canadians, health officials said on Sunday, April 26 the most reported death in a day since the outbreak.
It is the sixth consecutive day that the nationwide death rates from COVID-19 set or tied the mark for most deaths in a single day.
All but five of those deaths were people living in long-term care facilities.
As of Sunday, 272 people have died from illness in Minnesota.
Hennepin County residents account for 22 of the 28 deaths. Health officials also reported a COVID-19 death in Olmsted County over the weekend the sixth death in the area.
A total of 156 confirmed COVID-19 cases were identified in Minnesota, bringing them to 3,602. Of these, 1,774 people have recovered and are no longer required to be exiled.
Currently, 285 people are hospitalized for the virus, with 115 requiring treatment in the intensive care unit. The number of patients in the ICU has dropped since it peaked at 126 on April 20.
As a public service, we have made this article available to everyone regardless of subscription status. If this coverage is important to you, consider supporting local journalism by clicking the subscribe button in the top right corner of the homepage.
Minnesota Department of Health hotline COVID-19: 651-201-3920.
Discrimination hotline COVID-19: 833-454-0148
Minnesota Department of Health COVID-19: Coronavirus Disease (COVID-19) website.
When eventually the coronavirus crisis begins to recede and we return to an approximation of normality no matter how socially distanced or how much handwashing it involves we can expect some kind of international initiative to prevent, or at least limit, the spread of future lethal viruses. As a species we are pretty good at learning from recent experience. Its whats known as the availability heuristic the tendency to estimate the likelihood of an event based on our ability to recall examples.
But as the moral philosopher Toby Ord argues in his new book, The Precipice, we are much less adept at anticipating potential catastrophes that have no precedent in living memory. Even when experts estimate a significant probability for an unprecedented event, he writes, we have great difficulty believing it until we see it.
This was precisely the problem with the coronavirus. Many informed scientists predicted that a global epidemic was almost certain to break out at some point in the near future. Aside from the warnings of legions of virologists and epidemiologists, the Microsoft founder, Bill Gates, gave a widely disseminated Ted Talk in 2015 in which he detailed the threat of a killer virus. For a while now, a pandemic has been one of the two most prominent catastrophic threats in the governments risk register (the other is a massive cyberattack).
But if something hasnt yet happened, there is a deep-seated temptation to act as if its not going to happen. If that is true of an event, like this pandemic, that will kill only a tiny fraction of the worlds population, its even more the case for what are known as existential threats. There are two definitions of existential threat, though they often amount to the same thing. One is something that will bring a total end to humanity, remove us as a species from this planet or any other. The other, only slightly less troubling, is something that leads to an irrevocable collapse of civilisation, reducing surviving humanity to a prehistoric state of existence.
An Australian based at Oxfords Future of Humanity Institute, Ord is one of a tiny number of academics working in the field of existential risk assessment. Its a discipline that takes in everything from stellar explosions right down to rogue microbes, from supervolcanoes to artificial superintelligence.
Ord works through each potential threat and examines the likelihood of it occurring in the next century. For example, the probability of a supernova causing a catastrophe on Earth he estimates to be less than one in 50m. Even adding all the naturally occurring risks together (which includes naturally occurring viruses), Ord contends that they do not amount to the existential risk presented individually by nuclear war or global heating.
Most of the time, the general public, governments and other academics are largely content to neglect most of these risks. Few of us, after all, enjoy contemplating the apocalypse.
In any case, governments, as former Conservative minister Oliver Letwin reminds us in his recent book Apocalypse How?, are usually preoccupied with more pressing issues than humanitys demise. Everyday problems like trade agreements demand urgent attention, whereas hypothetical future ones such as being taken over by machines can always be left for tomorrow.
But given that were living through a global pandemic, now is perhaps an opportune moment to think about what can be done to avoid a future cataclysm. According to Ord, the period we inhabit is a critical moment in the history of humanity. Not only are there the potentially disastrous effects of global heating but in the nuclear age we also possess the power to destroy ourselves in a flash or to at least leave the question of civilisations survival in the balance.
Thus Ord believes the next century will be a dangerously precarious one. If we make the right decisions, he foresees a future of unimaginable flourishing. If we make the wrong ones, he maintains that we could well go the way of the dodo and the dinosaurs, exiting the planet for good.
When I speak to Ord over Skype I remind him of the unsettling odds he awards humanity in this life-and-death struggle between our power and our wisdom. Given everything I know, he writes, I put the existential risk this century at around one in six.
In other words, the 21st century is effectively one giant game of Russian roulette. Many people will recoil from such a grim prediction, while for others it will fuel the anxiety that is already rife in society.
He agrees but says that he has tried to present his modelling in as calm and rational a fashion as possible, making sure to take into account all the evidence that suggests the risks are not large. One in six is his best estimate, factoring in that we make a decent stab at dealing with the threat of our destruction.
If we really put our minds to it and mount a response equal to the threat, the odds, he says, come down to something more like 100-1 for our extinction. But, equally, if we carry on ignoring the threat represented by advances in areas like biotech and artificial intelligence, then the risk, he says, would be more like one in three.
Martin Rees, the cosmologist and former president of the Royal Society, co-founded the Centre for the Study of Existential Risk in Cambridge. He has long been involved in raising awareness of looming disasters and he echoes Ords concern.
Im worried, he says, simply because our world is so interconnected, that the magnitude of the worst potential catastrophes has grown unprecedentedly large, and too many have been in denial about them. We ignore the wise maxim the unfamiliar is not the same as the improbable.
Letwin warns of an overdependence on the internet and satellite systems, allied with limited stocks of goods and long supply chains. These are ideal conditions for sabotage and global breakdown. As he writes, ominously: The time has come to recognise that more and more parts of our lives of society itself depend on fewer and fewer, more integrated networks.
Complex global networks certainly increase our vulnerability to viral pandemics and cyberattacks, but neither of those outcomes qualify as a serious existential risk in Ords book. The pandemics he is concerned about are not of the kind that break out in the wet markets of Wuhan, but rather those engineered in biological laboratories.
Although Ord draws a distinction between natural and anthropogenic (human-made) risks, he argues that this line is rather blurry when it comes to pathogens, because their proliferation has been significantly increased by human activity such as farming, transport, complex trade links and our congregation in dense cities.
Yet like so many aspects of existential threat, the idea of an engineered pathogen seems too sci-fi, too far-fetched, to grab our attention for long. The international body charged with policing bioweapons is the Biological Weapons Convention. Its annual budget is just 1.4m (1.2m). As Ord points out with due derision, that sum is less than the turnover of the average McDonalds restaurant.
If thats food for thought, Ord has another gastronomic comparison thats even harder to swallow. While hes not sure exactly how much the world invests in measuring existential risk, hes confident, he writes, that we spend more on ice-cream every year than on ensuring that the technologies we develop dont destroy us.
Ord insists that he is not a pessimist. There are constructive measures to be taken. Humanity, he says, is in its adolescence, and like a teenager that has the physical strength of an adult but lacks foresight and patience, we are a danger to ourselves until we mature. He recommends that, in the meantime, we slow the pace of technological development so as to allow our understanding of its implications to catch up and to build a more advanced moral appreciation of our plight.
He is, after all, a moral philosopher. This is why he argues that its vital that, if humanity is to survive, we need a much larger frame of reference for what is right and good. At the moment we hugely undervalue the future, and have little moral grasp of how our actions may affect the thousands of generations that could or alternatively, might not come after us.
Our descendants, he says, are in the position of colonised peoples: theyre politically disenfranchised, with no say in the decisions being made that will directly affect them or stop them from existing.
Given everything I know, I put the existential risk this century at around one in six
Just because they cant vote, he says, doesnt mean they cant be represented.
Of course, there are also concrete issues to address such as global heating and environmental depredation. Ord acknowledges that climate change may lead to a global calamity of unprecedented scale, but hes not convinced that it represents an actual existential risk to humanity (or civilisation). Thats not to say that it isnt an urgent concern: only that our survival isnt yet on the line.
Perhaps the biggest immediate threat is the continued abundance of nuclear weapons. Since the end of the cold war, the arms race has been reversed and the number of active warheads cut from more than 70,000 in the 1980s to about 3,750 today. Start (the Strategic Arms Reduction Treaty), which was instrumental in bringing about the decrease, is due to lapse next year. From what I hear at the moment, says Ord, the Russians and Americans have no plan to renew it, which is insane.
Sooner or later all questions of existential risk come down to a global understanding and agreements. Thats problematic, because while our economic systems are international, our political systems remain almost entirely national or federal. Problems that affect everyone are consequently owned by no one in particular. If humanity is to step back from the precipice, it will have to learn how to recognise its common bonds as greater than its differences.
There are many predictions currently being made about how the world might be changed by the coronavirus. The philosopher John Gray recently declared that it spelt the end of hyperglobalisation and the reassertion of the importance of the nation state.
Contrary to the progressive mantra, Gray wrote in an essay, global problems do not always have global solutions the belief that this crisis can be solved by an unprecedented outbreak of international cooperation is magical thinking in its purest form.
But nor can individual countries afford to turn their backs on the world, at least not for long. The pandemic may not engender deeper international cooperation and a keener appreciation of the fact that we are, so to speak, all in it together. Ultimately, though, we will have to arrive at that kind of unity if were to avoid far greater afflictions in the future.
