AstraZeneca recipients may soon get to choose which vaccine they want for second shot

The country's chief public-health officer expects Canadians who got the Oxford-AstraZeneca COVID-19 vaccine as their first dose will soon be able to choose which vaccine they want for their second shot.
    
Dr. Theresa Tam says a small Spanish study on mixing and matching vaccines reported that giving a Pfizer-BioNTech shot for the second dose after AstraZeneca is safe.
    
It actually produced twice as many antibodies as a second dose of AstraZeneca.
    
The National Advisory Committee on Immunization is still awaiting further data from another mixing-and-matching study underway in the United Kingdom.
   
 About 2.1-million Canadians were vaccinated with AstraZeneca, but most provinces have paused using it for first doses amid 21 confirmed cases of a vaccine-induced blood-clotting disorder that has claimed three lives.