Even if you already got your COVID-19 vaccine, you might soon need another one. Vaccine developers are already working on COVID-19 vaccine booster shots, which are meant to rev up your protection against the virus.
But some experts aren’t sure we’ll actually need them, even though the research that goes into figuring that out is necessary. Here’s what we know about COVID-19 vaccine boosters so far.
Why might we need booster shots?
A booster shot is intended to do what the name suggests: boost your immune response to a particular pathogen after an initial vaccine dose. “The additional dose ramps up the antibody response in your body,” Krutika Kuppalli, M.D., pandemic preparedness expert and assistant professor of medicine in the department of infectious diseases at the Medical University of South Carolina, tells SELF.
For instance, after you get your meningococcal conjugate vaccines at age 11 or 12, you should get a booster around age 16, SELF explained previously. And adults should get booster shots to protect against tetanus and diphtheria every 10 years or so. As with these other vaccines, a booster shot may increase your protection against COVID-19 by stimulating the production of additional antibodies, Dr. Kuppalli says.
There are essentially two scenarios in which a COVID-19 vaccine booster would be needed. First, you may need them to extend the protection after your immunity from the first COVID-19 vaccine you got wanes, like with 10-year tetanus boosters. Second, boosters may be necessary to expand protection against new variants of the coronavirus as it mutates.
Because the COVID-19 vaccines are relatively new, we don’t yet know how long protection from the initial vaccine doses will last. This is especially important to monitor because there have been a few cases in which people who’ve been infected with COVID-19 contract it a second time, Suman Das, Ph.D., an associate professor of medicine at Vanderbilt University Medical Center who studies the evolution of viruses, tells SELF.
So far, data suggests the body’s immune response to the initial vaccine regimen is strong and long-lasting. Pfizer and its partner BioNTech continue to monitor the effectiveness of their vaccine and reported in a press release that the vaccine is still 91% effective at preventing symptomatic COVID-19 infections six months after inoculation, just slightly reduced from the 95% achieved in clinical trials and 94% seen in real-world studies. But, ultimately, we’ll need to keep monitoring it to see how long that response lasts.
Boosters could be available as early as this fall or winter, according to statements from the CEOs of Pfizer and Moderna. While boosters will likely be offered for everyone, they may be more important for some parts of the population than others, Dr. Kuppalli said. For example, immunocompromised people may be at a higher risk and benefit more from an immunity boost.
New coronavirus variants will be an important factor.
There are reports of a few coronavirus variants that may be able to reduce the effectiveness of the current COVID-19 vaccines, so a booster shot could help address that by targeting those strains specifically.
New strains of SARS-CoV-2 arise naturally as the virus replicates. The virus does very little proofreading as it copies itself, so there’s likely to be a mistake known as a mutation, Dr. Das says. The more the virus spreads and replicates, the more mutations will be introduced. Not all of the mutations will be concerning, but it’s always a possibility that one of them will make it easier for the virus to escape the protection of the vaccine.