Results of a new multicenter study published in the New England Journal of Medicine found that vaccination with a primary series of the Pfizer-BioNTech mRNA COVID-19 vaccine reduced the risk of COVID-19-associated hospitalizations in children ages 5-11 years by two-thirds during the Omicron period. Among adolescents ages 12-18 years who were vaccinated with a primary series of Pfizer-BioNTech vaccine, protection against COVID-19-associated hospitalization during the Omicron period was lower than during the Delta period, similar to what has been previously shown among adults. Levels of protection against critical COVID-19 requiring life-supporting interventions remained high in vaccinated adolescents during both the Delta and the Omicron periods.