If you are fully vaccinated against COVID-19, you have probably been able to breathe a sigh of relief. But how long can you expect this feeling to last? The CDC has yet to make a guess about the duration of immunity after vaccination on your website, but some studies have given us some pointers.
And so far it’s mostly good news. A letter from a vaccine research group to the New England Journal of Medicine April (you can think of these letters like mini-studies) found that people still had strong protection six months after the second dose of the Moderna vaccine. The group writes: “Although the antibody titers and assays that best correlate with the effectiveness of the vaccine are not currently known, antibodies raised by mRNA-1273 persisted six months after the second dose, as did three different ones serological assays. ”So did Pfizer announced in April that people who received the Pfizer vaccine still had strong protection six months after their second dose.
These study results don’t mean that protection only lasts six months, just that immunity at the six-month checkpoint is still strong. Keep in mind that both vaccines were approved in December so the vaccine has only been on the market for six months. Even vaccine trial subjects only had an average of two months of follow-up data by the time vaccine manufacturers applied for approval, so they’re just a tiny bit ahead of the rest of us. (The Johnson & Johnson vaccine runs on a later schedule than the rest as its studies were completed a few months after the other two.)
Attempts with booster shots have already started, but so far it looks like this it will likely be at least a year before someone needs one, and possibly longer. Immunity is a complex thing, and scientists have not yet established a test that can tell the difference between someone protected against COVID-19 and someone who is still vulnerable. We’ll most likely learn more in the months to come, but right now we can probably be sure that our vaccines will be good for at least six months, probably at least a year, and maybe longer.
