Pfizer vaccine significantly less effective in children ages five to 11, study shows

Strikingly higher rates of decline in effectiveness for younger children suggest the lower dose they receive may be the reason

The Pfizer/BioNTech Covid-19 vaccine is less effective in children aged five to 11 than in adolescents and adults, according to new data from New York state health officials.

The new research was announced shortly after federal authorities relaxed masking guidance and a day after Eric Adams, the mayor of New York, said he would probably follow Governor Kathy Hochul in ending a mask mandate in city schools.