LOS ANGELES, March 20 (Xinhua) -- The magnitude and quality of a key immune cell's response to vaccination with two doses of the Pfizer-BioNTech COVID-19 vaccine were considerably lower in people with prior SARS-CoV-2 infection compared to people without prior infection, according to a new study published on Monday.
The study, co-funded by the U.S. National Institutes of Health, also found the level of this key immune cell that targets the SARS-CoV-2 spike protein was substantially lower in unvaccinated people with COVID-19 than in vaccinated people who had never been infected.
