such a difference for this age group? >> the dosage of this age group 5 to 11 is a third of the dosage that 12-year-olds and above received for the pfizer vaccine, so it could be dose-related. >> reporter: news coming days after the cdc relaxed it guidance on mask-wearing. california, oregon and washington saying mask mandates will soon end in schools. new york's governor announced the same. some connecticut students returned to class mask sgles they were so excited today to not have to wear the mask. >> reporter: two weeks ago pfizer said it was postponing seeking fda authorization for a vaccine for kids 6 month to 4 years old after trials showed it didn't work well. now news about the vaccine for 5 to 11-year-olds not being as effective. >> parents might be skeptical and hesitant and say a vaccine does not help due to this data but that's not true. it did still protect against death and serious disease and did not show any safety issues. >> reporter: pfizer says it's