Pfizer, Moderna vaccines now preferred second dose for AstraZeneca recipients: NACI
June 17 2021
''OTTAWA - The National Advisory Committee on Immunization says it is now recommending people who got the Oxford-AstraZeneca vaccine first should get Pfizer-BioNTech or Moderna for their second shot.
Previously, NACI had said AstraZeneca recipients could choose whether to get a second dose of the same vaccine, or an mRNA vaccine. But in new guidance released Thursday, NACI says Pfizer or Moderna are now “preferred” as the second dose.
The guidance is based on growing evidence that a second dose of an mRNA vaccine produces a stronger immune response, and because of the low but serious risk of vaccine-induced blood clots associated with getting AstraZeneca.
The advice doesn't mean people can't still choose AstraZeneca if they want, or if they are allergic to the mRNA vaccines.''
“People who received two doses of AstraZeneca/COVISHIELD vaccine can rest assured that the vaccine provides good protection against infection and very good protection against severe disease and hospitalization,” NACI's advice says.
As of June 5, 2.1 million Canadians had received one dose of AstraZeneca, and 15,186 had received two doses.''