How Long Will COVID-19 Vaccine Protection Last? Heres What Doctors Know So Far – Prevention.com
April 7, 2021
More than 63 million people have been fully vaccinated against COVID-19an exciting step toward ending the pandemic after more than a year of lockdowns and mask wearing. Recently, the U.S. hit a new record by administering more than 4 million doses in 24 hours. President Joe Biden also confirmed that a majority of U.S. adults will be eligible for the vaccine by April 19, well before his initial May 1 deadline.
Clinical trials have shown that the the authorized coronavirus vaccines are safe and highly effective at preventing severe forms of COVID-19. But theres still one question that researchers are in the process of answering: How long does vaccine protection actually last? And will follow-up doses be necessary to extend immunity and ward off new, more infectious variants of the virus?
Data continues to evolve, but it looks promising. Heres what experts know so far.
On April 1, Pfizer announced that its COVID-19 vaccine offers up to six months of strong protection against symptomatic COVID-19. Specifically, data from its phase 3 study showed that the vaccine was 91.3% effective at preventing COVID-19 for up to six months after the second dose and 100% effective against severe disease as defined by the CDC.
At this point, six months is the time frame for which they have secure information, explains William Schaffner, M.D., an infectious disease specialist and professor at the Vanderbilt University School of Medicine.
But that doesnt mean that the vaccine is only good for six months. Its possible that the Pfizer vaccine, and others like it, will provide immunity for longer than that, says infectious disease expert Amesh A. Adalja, M.D., senior scholar at the Johns Hopkins Center for Health Security. He bases his prediction from what we know about the flu vaccine, which is good for at least a year.
As for Modernas and Johnson & Johnsons respective vaccines, those were authorized by the Food and Drug Administration after the Pfizer vaccine, so theres currently less data on their long-term efficacy.
However, Richard Watkins, M.D., an infectious disease specialist and professor of internal medicine at the Northeast Ohio Medical University, believes Modernas vaccine will provide protection for a similar period of time as Pfizers vaccine, since it has the same mechanism of action. (Both the Pfizer and Moderna vaccines use mRNA technology.)
The Johnson & Johnson vaccine uses a different mechanismits a traditional adenovirus vaccine, like the flu vaccinebut it should also offer similar protection, notes Dr. Schaffner. Why? The outcomeantibodies to SARS-CoV-2is the same with both types of vaccines, he says.
Its not entirely clear right now, but Dr. Schaffner says it wont be like an on and off switch. If protection from the vaccine wears off, it will fade slowly, he says. Because every persons immune system is slightly different, it may happen at a different pace for each individual.
The good news is, doctors believe that if vaccinated people end up contracting COVID-19 down the road, their symptoms will certainly be less severe. There should be some residual protection for quite some time, Dr. Schaffner says. It goes back to the gradual decrease in protection. Basically, its expected that your immune system will at least remember that its seen something that looks like this coronavirus before and then go to work.
A small study published in January found that 95% of people who contracted COVID-19 still had antibodies to the virus up to eight months after they were infectedand experts predict that protection from the vaccine will last longer than natural immunity (a.k.a. becoming ill with COVID-19 and recovering). Not only that, Dr. Schaffner believes protection from the vaccine will likely be more complete and offer more protection against variants than natural immunity. More research is needed to prove that theory, though.
Currently, both Pfizer and Moderna are studying whether a booster shot may be helpful in maintaining COVID-19 protection following initial vaccination, especially when it comes to newly-emerging variants.
Its too early to determine whether or not booster doses may be needed and what the interval may be, Dr. Adalja says, but theres a good chance follow-up shots will be necessary, especially since there is a rare but real chance of having a breakthrough infection. This occurs when someone who is fully immunized against the virus still ends up being infected by it.
These vaccines that were using are fabulous but theyre not perfect, Dr. Schaffner says. While they are incredibly effective at preventing serious disease, there is still a slim chance for a minor COVID-19 illness to occur after vaccination.
I would think we would need boostering at some point, whether its annually or every two or five years, says Dr. Schaffner. This virus will likely be with us for a long time, the way influenza is, and there will be variants and mutations that would require a booster to target them.
This article is accurate as of press time. However, as the COVID-19 pandemic rapidly evolves and the scientific communitys understanding of the novel coronavirus develops, some of the information may have changed since it was last updated. While we aim to keep all of our stories up to date, please visit online resources provided by the CDC, WHO, and your local public health department to stay informed on the latest news. Always talk to your doctor for professional medical advice.
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How Long Will COVID-19 Vaccine Protection Last? Heres What Doctors Know So Far - Prevention.com
