Children ages 5 to 11 who received the Pfizer/BioNTech Covid-19 vaccine were 68 percent less likely to be hospitalised during the Omicron wave in the United States than unvaccinated children, according to a study published on Wednesday.

Adolescents aged 12-18 who received two shots of the vaccine were around 40 percent less likely to be hospitalised with the Omicron variant of the virus, the study led by scientists from the US Centers for Disease Control and Prevention (CDC) and Boston Children's Hospital found. It was published in the New England Journal of Medicine.

The risk of more serious outcomes, including...