Dr. Paul Offit explains why antibody testing is not routinely recommended after COVID-19 vaccination.
Should I get an antibody test to know If the COVID-19 vaccine worked?
Paul Offit, MD: Hi, my name is Paul Offit. I'm talking to you today from the Vaccine Education Center at the Children's Hospital of Philadelphia. It is Tuesday, May the 4th, 2021. One thing that people often wonder is, how do I know that after I’ve gotten these vaccines that I am protected? Isn’t there a someway to figure out whether or not I have had an adequate immune response?
When this comes up I find is when people who get say the second dose of the Moderna or Pfizer vaccines or get a single dose of the Johnson & Johnson vaccine, they’ve heard they’re supposed to develop symptoms, like fatigue or fever or muscle ache or joint ache. And when they don’t develop those symptoms, they worry that maybe they haven’t made a very good immune response to the vaccine. First of all, they should be reassured that although 95% of people who get these vaccines, say the mRNA vaccines, or certainly roughly 85% who get the Johnson & Johnson vaccine, will be protected against severe and critical disease. So, that’s good. And so, if they haven’t developed those kinds of symptoms, it doesn’t mean at all that they’re not going to be protected.
But still some people may wonder whether or not they’re going to be protected, should they get antibody titers to see whether or not they’ve had an adequate immune response. There are studies that are showing that not only do you make an antibody response, but you also make other so-called cellular immune responses like B cells, which are the cells that make antibodies, and if you can develop high frequencies of memory B cells, then you’re fine even if you don’t have high antibody titer. Similarly, there are other cells called T helper cells, which help B cells make antibodies, and if you develop high frequencies of those cells, you are also likely to be protected, and protected broadly, even though you may have a lower antibody response.
So generally, my feeling on this is don’t get antibody titers because it’s not clear that when you get those titers you can say with confidence that I know I am going to be protected above a certain level or I know I won’t be protected below a certain level, and trust that you are likely to fall into that group, the 95% group or 85% group (in the case of Johnson & Johnson vaccine), that are likely to be protected. So, I actually don’t recommend getting those antibody tests routinely.
Related Centers and Programs: Vaccine Education Center
Last Reviewed on Jun 01, 2021