COVID-19 Vaccine Breakthrough Infections Reported to CDC — United States, January 1–April 30, 2021
CDC COVID-19 Vaccine Breakthrough Case Investigations Team, CDC COVID-19 Vaccine Breakthrough Case Investigations Team, Meseret G. Birhane, Sara Bressler, Gregory Chang, Thomas A. Clark, Layne Dorough, M. L. Fischer, Louise Francois Watkins, Jason Goldstein, Kiersten J. Kugeler, Gayle Langley, K. Danielle Lecy, Stacey W. Martin, Felicita Medalla, Kiren Mitruka, Leisha D. Nolen, Katrin S. Sadigh, Robin Spratling, Gail Thompson, A. Angelica Trujillo
Abstract
COVID-19 vaccines are a critical tool for controlling the ongoing global pandemic. The Food and Drug Administration (FDA) has issued Emergency Use Authorizations for three COVID-19 vaccines for use in the United States.* In large, randomized-controlled trials, each vaccine was found to be safe and efficacious in preventing symptomatic, laboratory-confirmed COVID-19 (1-3). Despite the high level of vaccine efficacy, a small percentage of fully vaccinated persons (i.e. received all recommended doses of an FDA-authorized COVID-19 vaccine) will develop symptomatic or asymptomatic infections with SARS-CoV-2, the virus that causes COVID-19 (2-8).