Canada’s National Advisory Committee on Immunization (NACI) has announced its updated guidelines to allow mixing and pairing of approved coronavirus vaccines in most scenarios.
According to the Chief Public Health Officer of Canada, NACI has worked quickly to adapt guidelines for the use of coronavirus vaccines in Canada to ensure the optimal protection of Canadians in the face of ever-changing circumstances during the current pandemic.
1/5 The Council of Chief Medical Officers of Health relies on the latest evidence and expert advice on the #Vaccines against covid19. We support the National Advisory Committee on Immunization (NACI) guidelines on mixed immunization schedules and dose intervals. https://t.co/3fqClenAoN
– Dr. Theresa Tam (@CPHO_Canada)
June 2, 2021
Four COVID-19 vaccines, developed by Moderna, Pfizer, Johnson & Johnson and AstraZeneca, have been authorized for use in Canada to date.
Updated vaccine mixing and pairing guidelines:
• According to updated guidelines from Canada, people who received the first dose of AstraZeneca vaccine may be given Moderna or Pfizer-BioNTech for their second dose, unless it is not recommended.
• The new NACI guidelines also indicated that Moderna and Pfizer vaccines can be mixed for the first and second doses.
• However, the NACI does not recommend AstraZeneca after the first injection of Pfizer or Moderna due to limited data and safety concerns with the use of this combination.
What is the basis for the updated guidelines by NACI?
The updated NACI guidelines are based on emerging research from the UK and Spain which found that the corresponding and mixed Pfizer and AstraZeneca vaccines were both safe and effective in preventing the virus.
Chief Public Health Officer Theresa Tam explained that this is not a new concept. Having a multidose series in terms of vaccines given by manufacturers is something that public health has used over time for many other vaccines.
She further added that when the immunization schedule and supplies change, it is not an unusual thing to do.
Recommendation to get the same dose:
According to Theresa Tam, while the National Immunization Advisory Committee has recommended that vaccines can be used safely in combination, people should try to get the same serial dose, if possible, especially when receiving Moderna. or Pfizer.
Tam said NACI does not recommend using them interchangeably, but try to use the same vaccine for the second dose. She added that if the person cannot find it or know what someone had, whether it was Moderna or Pfizer for the first dose, another vaccine may be considered.
COVID-19 vaccine in Canada:
According to the Public Health Agency of Canada, more than 13 million people have received at least one dose of Pfizer vaccine in Canada, compared to more than 3.5 million Moderna vaccines and 2.1 million AstraZeneca vaccines as of May 22. 2021.