How Long Will COVID-19 Vaccine Immunity Last?

In this short video, Dr. Hank Bernstein talks about immunity after COVID-19 vaccination.


How Long Will COVID-19 Vaccine Immunity Last?

Hank Bernstein, MD: I'm Hank Bernstein and I'm speaking on behalf of the Vaccine Education Center at Children's Hospital of Philadelphia. The question, “How long will vaccine immunity last?” The answer, who knows. Since the vaccines were developed with unprecedented speed, and since they've only been in use for several months now, we really don't have exact answers for how long long-term immunity will last. There's very limited information about long-term immunity at this point, but this is being covered and studied very carefully.

Remember that COVID vaccines began in the summer of 2020. So, we're not exactly sure about the length of protection, and we won't know for sure until we collect more data. Remember that the kinds of protection that we're talking about are not just how many antibodies we make, but also how well those antibodies neutralize the virus. That's the most important. The number of antibodies is important, but more importantly, how well those antibodies neutralize the virus whenever we're exposed.

Now, the key to that long-lasting protection involves the memory cells of our immune system, which are the cells that quickly expand and produce antibodies when they encounter any germs. As I mentioned, neutralizing antibodies are also key because they work to attack the virus whenever we're exposed. Studies have been quite promising about the durability of the antibodies going forward. It's kind of natural, as you can imagine, that our immunity can vary over time and levels may drop, but a recent study in The New England Journal of Medicine showed that while antibody levels may decline slightly over time after the first dose, they remained quite elevated after the second dose and stay elevated for at least three months following that second dose. This gives us encouragement and excitement that the duration of immunity may be longer than we anticipate, but only time will tell. Coronaviruses are pretty smart and they mutate, so we're really going to have to stay tuned.

Related Centers and Programs: Vaccine Education Center

Last Reviewed on Mar 16, 2021