The effectiveness of the Pfizer/BioNTech Covid-19 vaccines for children waned quickly during the Omicron surge, especially among children ages 5 to 11, but was still protective against severe disease, according to new data from the New York State Department of Health.

(SOURCE) https://www.cnn.com/2022/02/28/health/pfizer-vaccine-effectiveness-kids-omicron/index.html