News CDC approves mix-and-match booster shots; Pfizer-BioNTech vaccine 90% effective for kids 5 to 11: COVID-19 updates October 22, 2021 Celina Tebor and Christine Fernando, USA TODAY Comments Off on 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.