While omicron symptoms tend to be milder than previous variants, its high transmissibility has caused more people to become infected.
Author: Celina Tebor and Christine Fernando, USA TODAY
CDC approves mix-and-match booster shots; Pfizer-BioNTech vaccine 90% effective for kids 5 to 11: COVID-19 updates
After the CDC approved booster shots for all three vaccines, it now will evaluate the safety of the Pfizer-BioNTech vaccine for kids.