Effectiveness of 2-Dose BNT162b2 (Pfizer BioNTech) mRNA Vaccine in Preventing SARS-CoV-2 Infection Among Children Aged 5–11 Years and Adolescents Aged 12–15 Years — PROTECT Cohort, July 2021–February 2022
Ashley Fowlkes, Sarang K. Yoon, Karen Lutrick, Lisa Gwynn, Joy Burns, Lauren Grant, Andrew L. Phillips, Katherine Ellingson, Maria Ferraris, Lindsay LeClair, Clare Mathenge, Young M. Yoo, Matthew S. Thiese, Lynn B. Gerald, Natasha Schaefer Solle, Zuha Jeddy, Leah Odame‐Bamfo, Josephine Mak, Kurt T. Hegmann, Joe K. Gerald, Jezahel S. Ochoa, Mark Berry, Spencer Rose, Julie Mayo Lamberte, Purnima Madhivanan, Felipe A Pubillones, Ramona P. Rai, Kayan Dunnigan, John T. Jones, Karl Krupp, Laura Edwards, Edward J. Bedrick, Brian Sokol, Ashley A. Lowe, Hilary McLeland-Wieser, Krystal S. Jovel, Deanna E. Fleary, Sana Khan, Brandon Poe, James Hollister, Joanna Lopez, Patrick Rivers, Shawn C. Beitel, Harmony L. Tyner, Allison L. Naleway, Lauren E.W. Olsho, Alberto J. Caban‐Martinez, Jefferey L. Burgess, Mark G. Thompson, Manjusha Gaglani
Abstract
prospective cohort of 1,364 children and adolescents aged 5-15 years was tested weekly for SARS-CoV-2, irrespective of symptoms, and upon COVID-19-associated illness during July 25, 2021-February 12, 2022. Among unvaccinated participants (i.e., those who had received no COVID-19 vaccine doses) with any laboratory-confirmed SARS-CoV-2 infection, those with B.1.617.2 (Delta) variant infections were more likely to report COVID-19 symptoms (66%) than were those with Omicron infections (49%). Among fully vaccinated children aged 5-11 years, VE against any symptomatic and asymptomatic Omicron infection 14-82 days (the longest interval after dose 2 in this age group) after receipt of dose 2 of the Pfizer-BioNTech vaccine was 31% (95% CI = 9%-48%), adjusted for sociodemographic characteristics, health information, frequency of social contact, mask use, location, and local virus circulation. Among adolescents aged 12-15 years, adjusted VE 14-149 days after dose 2 was 87% (95% CI = 49%-97%) against symptomatic and asymptomatic Delta infection and 59% (95% CI = 22%-79%) against Omicron infection. Fully vaccinated participants with Omicron infection spent an average of one half day less sick in bed than did unvaccinated participants with Omicron infection. All eligible children and adolescents should remain up to date with recommended COVID-19 vaccinations.