COVID-19 infection reduces vaccine effectiveness.

A study funded by the National Institute of Allergy and Infectious Diseases (NIAID) found that the immune-cell response to the Pfizer-BioNTech COVID-19 vaccine was weaker in people with prior SARS-CoV-2 infection compared to those without prior infection. The study also found that unvaccinated people with COVID-19 had substantially lower levels of immune cells that target the SARS-CoV-2 spike protein than vaccinated people who had never been infected. The findings suggest that the virus damages an important immune-cell response, highlighting the need to develop vaccination strategies to specifically boost antiviral T-cell responses in people previously infected with SARS-CoV-2.