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I’m Covid Antibody Negative Despite Being Fully Vaccinated; Is That a Problem?
A physician looks at how our immune systems respond to the Covid vaccine
I received my second dose of the Pfizer-BioNTech Covid-19 vaccine on January 4th of this year. I donated blood on March 19th. The donation center routinely checks for antibodies to Covid-19 in their donors. To my surprise, I was antibody negative. Does that mean my vaccine didn’t work?
The short answer is, “no.” Here are two reasons why I’m not concerned, and if you find yourself in a similar situation, you need not worry either.
1) Antibody tests aren’t perfect
Not all antibody tests are the same. There are a number of different classes of antibodies or immunoglobulins (Ig). For instance, IgM is made by the body early in the course of an illness, but levels of IgM decline sharply within days to weeks. On the other hand, IgG antibodies aren’t produced until later in the course of an illness but tend to last for months, or even years…
