AstraZeneca in the first round of COVID-19 vaccinations will be able to choose which vaccine they get for their second dose.Dr.
Theresa Tam‘s comments came hours after a small Spanish study on mixing and matching vaccines reported that giving a Pfizer-BioNTech shot for the second dose after AstraZeneca is safe and produced twice as many antibodies as a second dose of AstraZeneca.The National Advisory Committee on Immunization, known as NACI, is still awaiting further data from another mixing-and-matching study underway in the United Kingdom, but Tam said advice on second doses should be ready before most people are due to get their second vaccination.