Study tracks COVID-19 antibodies after vaccines, natural infection

Editor's Note

In this study, researchers from the University of Virginia, Charlottesville, find that antibodies generated by the Pfizer-BioNTech COVID-19 vaccine rise more slowly and decline more quickly than those generated by the Moderna vaccine, but both vaccines generated similar peak levels of antibodies. This result differs from earlier findings that showed antibodies were higher after Moderna, but the researches say the discrepancy likely can be explained by the faster rate at which Pfizer antibodies decline.

The study also finds that older recipients of the Pfizer vaccine generated fewer antibodies than younger recipients, but age was not a factor with the Moderna vaccine.

In addition, after 6 months, antibodies elicited by the Pfizer vaccine but not Moderna were significantly lower than antibodies in unvaccinated patients who had been hospitalized 6 months earlier with COVID-19 infection.

Study participants included 243 individuals who worked at the University of Virginia.

Understanding how antibody levels decline may help physicians and policymakers gauge when boosters are needed and who should receive them, the researchers note.