After the remarkable development of effective COVID-19 vaccines last year, scientists are helping to refine understanding of the shots’ real-world performance. At UVA’s School of Medicine, researchers performed a head-to-head comparison of antibody response to the Pfizer and Moderna mRNA vaccines.
Antibody response was analyzed for 167 study participants about two weeks after the second shots. The results showed that on average “both vaccines elicited pretty high amounts of antibody,” says assistant professor of allergy and immunology Dr. Jeffrey Wilson, corresponding author on the study. However, he adds, there was a “statistically significant difference between the two,” with the Pfizer vaccine eliciting a slightly lower antibody response, mostly in participants over 50.
But whether these differences result in different outcomes among vaccinated individuals is unknown. And the fact that in their study the differing antibody response was found in older participants “prompts the suggestion that you need to look at subgroups in the population” to determine if one or the other vaccine would be better for those groups. Nevertheless, Wilson stresses, despite the subtle differences found in antibody levels, “at this point we still fully endorse both of these vaccines.”