Anthony Fauci, M.D., recognizes that at some point the protection he has from the COVID-19 vaccine will fade. But Dr. Fauci, director of the National Institute of Allergy and Infectious Diseases, told Business Insider that he won’t rely on antibody tests to figure out when that happens.
“You don’t want to assume that you’re going to have indefinite durability of protection,” he said in the interview. And when that protection wanes enough, he said, a booster shot may be necessary. These shots are essentially another dose of the COVID-19 vaccine meant to “boost” the immune response if the initial protection subsides. Or, if a new coronavirus variant emerges that the current vaccines can’t protect against, a booster shot may provide extra protection against that specific strain.
Dr. Fauci acknowledges that such tests are available for individuals, but doesn’t recommend that people use them to determine when they need a vaccine booster. “If I went to LabCorp or one of those places and said, ‘I would like to get the level of anti-spike antibodies,’ I could tell what my level is if I wanted to,” he said in the interview. “I didn’t do it.”
Antibody tests like these work by looking for antibodies in your blood that your body makes in response to COVID-19 or to a vaccine. And these tests can provide a convenient and useful sign that you have some level of antibodies in your blood and, therefore, some level of protection against the virus.
But the results from these tests generally don’t provide enough information with enough certainty to be useful as shorthand for “protected” or “not protected.” Antibodies are just one important part of the body’s response to the COVID-19 vaccines. And the tests just aren’t capable of capturing the full spectrum of immune responses that actually signify protection from the virus. Ultimately, while antibody tests provide one piece of (sometimes genuinely useful) data, they should not be used alone as a sign that you’re immune to COVID-19.
Rather than looking to antibody tests, Dr. Fauci will rely on two major signs to figure out when the widespread administration of booster shots may be appropriate. The first sign will be an increase in the number of breakthrough infections among people who got their vaccines in early 2020 through clinical trials. And the second sign will be laboratory research that shows vaccinated people’s immune protection from the virus is decreasing.
If and when COVID-19 booster shots become a necessity, Dr. Fauci says we’ll likely get them from our usual health-care providers on a standard schedule based on your age, underlying health conditions, and other vaccine schedules. “You don’t have to all individually get a blood test [to determine when you need a booster shot],” Dr. Fauci said.
For now, though, research suggests that the current vaccines remain highly effective against coronavirus variants—even the highly transmissible delta variant. And that protection appears to last a significant amount of time (possibly even years, according to the most recent research). But if and when booster shots become necessary, it’s reassuring to know you won’t have to get an individual blood test to find out if you need one.