Omicron has peaked. Will the COVID-19 pandemic ever end? – UCHealth

Will COVID ever end? Three UCHealth experts weigh in on where they think the coronavirus pandemic is headed and why. Photo: Getty Images.

The omicron surge has peaked and appears to be on a double-black-diamond downslope. Three major metro Denver counties dropped mask mandates last week. Statewide hospitalizations from this omicron-driven coronavirus wave peaked at 1,676 in mid-January and stood at 1,227 as of Feb. 2, a number the Colorado COVID-19 Modeling Group expects to fall to below 500 by the end of February.

Vaccination is a big part of the story: 68% of the states residents are fully vaccinated, which is among the top one-third nationally. Those quotation marks are there because, with a coronavirus variant as contagious as omicron, its really about the COVID-19 vaccine booster, and only about 48% of residents have had that third shot.

Perhaps a bigger part of the story is just how many of us have been infected with omicron and how many more of us will soon join them. The aforementioned modeling group estimated that, as of Jan. 25, about 42% of Colorado residents had already gotten omicron. Despite cases having peaked, the ride back down will take about a month, during which that figure will rise to 65% by late February, the group estimates. By midmonth, they estimate, 80% of residents will, through SARS-CoV-2 exposure, vaccination, or both, be immune to the variant. The end of the coronavirus pandemic feels near.

The end of coronavirus felt near after the widespread introduction of vaccines a year ago, too, and then came the delta variant, and then omicron. Two years into the coronavirus pandemic, we have learned not to declare victory over this cursed microscopic foot-massager. So where are we, and where might the coronavirus pandemic be headed? To find out, UCHealth Today talked to three UCHealth and University of Colorado School of Medicine experts: Dr. Jonathan Samet, dean of the Colorado School of Public Health and leader of the Colorado COVID-19 Modeling Group; Dr. David Beckham, a CU School of Medicine virologist and infectious disease specialist; and Ross Kedl, PhD, a CU School of Medicine immunologist and vaccine specialist. All work and do research on the Anschutz Medical Campus.

If go away means permanently gone, I think that the answer is no, Samet said.We already have routinely circulating coronaviruses that contribute to the common cold, and SARS-CoV-2 now has animal reservoirs like influenza does.

Samet added, though, that near-universal immunization with vaccines capable of conferring prolonged immunity could change that.

Its a low risk, Beckham says, and others agree. SARS-CoV-2 was attuned to invading human cells and skirting the human immune systems defenses from the beginning, and its gotten better at it since.

The likelihood of this same virus jumping back from an animal reservoir is pretty low, Beckham said. I think its just going to continue to circulate in people. Its become a people virus.

While there is no particular quantitative definition, Samet says, endemic means that the virus is with us and causing sporadic cases and outbreaks but not the surging wave of an epidemic.

Epidemiologists consider endemic to mean the rate of infection in a population is neither increasing or decreasing over time, Beckham says. You basically have a reproductive rate, or R0, of one, he says. Its just maintaining itself.

While that sounds better than pandemic (which is a border-spanning epidemic), endemic doesnt always equate to benign, he says. Ebola, dengue, and malaria are endemic diseases, and malaria alone infected 241 million people and killed 627,000 in 2020 alone.

Kedl says another difference between an epidemic/pandemic and endemic disease has to do with control.

An epidemic is one that we really have little control over. Its rising and falling at rates that we cant really pull the dial on, he says. With endemic disease, we have some degree of control, or a significant degree, such that all you really expect are limited outbreaks that dont go rampant across the population in an uncontrolled fashion. And that essentially describes the flu, right? It doesnt rage out of control, with the exception of something like the 1918 version.

Another way to phrase that is whether theres a broadly neutralizing immune response that tunes into different coronavirus variants, Beckham says. The science so far shows that while such a cross-reactive immune response happens with the coronavirus, its strength depends on how one was exposed.

Those who recovered from severe disease developed a nice, robust, long-lasting immune response that was protective, he said.

But those who had mild or even moderate disease saw a more variable immune response, meaning that protection dropped off after just a few months.

That variability is the reason why, after infection, we still recommend that people get vaccinated, because the vaccine does result in a long, durable kind of immune response, Beckham says. Natural immunity does not equal protection. Theres a lot of variability there. So, going out, getting COVID, and thinking youre done with it is probably not the way to think about this, because we definitely know people with milder infections dont develop great immune responses, and a vaccine is definitely protective for those people.

That vaccines developed for a now-extinct SARS-CoV-2 variant still work so well is an indication that immunity to one coronavirus strain extends protection to others, Kedl adds. Those infected with omicron may enjoy a strong immune boost, he adds. Its many mutations 30 on the spike protein alone suggest that It went in a number of different potential variant directions at once.

And so whichever direction the virus goes next, we may already be partly down that road to some degree in terms of our immunity, Kedl said. So omicron may have given us some potential advantages, even for the next variants. Time will tell whether thats true or not.

The original doses of the vaccines or a severe infection offer about 50% protection from repeat infection, and vaccines are highly effective at keeping people from getting sick enough to be hospitalized, Beckham says. While omicron is contagious enough to make repeat or breakthrough infections more common remnant antibodies arent bountiful enough in the nose and throat to stop the virus from gaining a foothold the more durable T-cell and memory B cell responses remain robust and appear to be preventing serious disease in those who arent immunocompromised for months and months, even against omicron, especially after boosting.

Kedl says the combination of vaccination and infection is incredibly potent, and not only elevating your level of immunity, but also the breadth of your immunity because its influenced both by the vaccine, which was for the original strain of virus we havent seen for two years, and whatever strain you got infected with, so it broadens your immune response.

Such hybrid immunity (in technical terms, a heterologous prime boost), he says, is a really, really powerful way of elevating your immunity.

Kedl adds that vaccine effectiveness should be measured in terms of preventing severe disease not in preventing infection.

The primary goal behind vaccination is to protect you from the most severe consequences of infection, independent of whether it stops you from getting infected or not, Kedl said. Using this more appropriate definition of efficacy, the vaccines have been amazingly protective, no matter what strain you look at. That said, studies have shown that fully vaccinated and boosted individuals are also highly protected against any infection at all, even from Omicron. Thats just icing on the cake.

Yes, Kedl says.

If you hadnt been boosted and got a breakthrough infection, Id get another shot and kick that immunity up as high as possible, because the virus is not leaving.

I cant speak to forever, but for now, using a respiratory protective device in crowded settings is reasonable, says Samet, who wears an N95 respirator when he travels to protect himself and others.

Beckham says its about calculating risk. Are you inside in close quarters? Are virus levels high? (In Colorado at the moment, thats the case: Samets modeling group estimates that one in 19 people are infected with omicron.) Are you at high risk of severe outcomes due to age, immune status, or vaccination status? Then consider a mask. If not, perhaps not.

Maybe there will be periods where we dont need masks, but I think you have to be flexible with the masking, depending on whats going on in the population, he said.

Kedl agrees with Beckham on the importance of evaluating ones own risk.

Show me where in the data it indicates any serious risk for a vaccinated and boosted person under 65 years of age who is in good health and with no risk factors, Kedl said. Ill save you the time: There isnt any.

But, he adds, if youre a 79-year-old with type 2 diabetes visiting a busy indoor place, masking may be the right choice even if you are vaccinated and boosted.

We have been outsourcing decisions about masking up, Kedl said. Those decisions now need to be attended to by each and every one of us, and I think we need to be considerate with each other as we work through those decisions.

The natural direction for viruses to head is in a more contagious, less virulent direction, Kedl said.

While theres no reason that the next strain couldnt be more virulent (that is, causing more severe disease), the coronavirus doesnt gain anything by mutating in that direction.

These viruses, they honestly dont care if they make you sick, Beckham says. They dont care if youre in the hospital. What theyre trying to do is infect you and then spread within the first five to seven days of that infection. Thats where the selection pressure is.

Samet agrees: Transmissibility and immune escape give advantage to a variant, not virulence, he said.

The coronavirus has followed the natural direction Kedl describes. Delta was twice as transmissible but no less virulent than alpha; omicron is twice as transmissible and less virulent than delta; and the BA.2 omicron subvariant is perhaps half again as transmissible as omicron but does not appear to cause more severe disease.

Its always possible, of course, to spin out a really dangerous variant. Its just not very likely, Kedl says. The less virulent they are, and the more contagious they are, the more likely they are to spread and to take over. And as a result, the immunity you develop against those are likely to make you resistant to a more virulent and/or less contagious strain. Those will just lose based on math.

The need for repeated vaccination will depend on how long-lasting protection against serious disease lasts, Beckham says.

As the coronavirus becomes endemic, severe disease not just case counts becomes the key metric.

It may just be that youre really well protected against severe disease and we never need another booster, Beckham said. We just dont have that data yet.

Kedls best guess is that SARS-CoV-2 will turn into another of the four current seasonal coronaviruses that cause common colds, and that vaccination will be along the lines of what we do for seasonal flu. Vaccination approaches will also depend on the nature of variants and the illnesses they cause.

The rate of variant generation is really, in my view, what will guide the frequency of boosting from here on out, Kedl said. My bet is that, for the next 10 years, every couple of years, therell be a new variant booster that you can get. And so, I would think, you would couple that with your flu vaccine, and youre good to go.

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Omicron has peaked. Will the COVID-19 pandemic ever end? - UCHealth