The Pfizer COVID-19 vaccine is protective against several SARS-CoV-2 variants that have emerged, according to new research presented in the journal mBio, an open-access journal of the American Society for Microbiology. While this is good news, the study also found that the only approved monoclonal antibody therapy for SARS-CoV-2 might be less effective against SARS-CoV-2 variants in laboratory experiments.