OTTAWA, ON, March 29, 2021 — After confirming last week that the benefits of the AstraZeneca COVID-19 vaccine outweigh the risks, Health Canada and NACI (National Advisory Committee on Immunization) have changed their recommendation to specify that the Oxford-AstraZeneca and Verity Pharmaceuticals/Serum Institute of India vaccines should not be used on people under the age of 55.
Health Canada previously communicated on its ongoing assessment of very rare adverse events reported in Europe of thrombosis (blood clots) with thrombocytopenia (low blood platelets) occurring after immunization with the AstraZeneca vaccine. The product information was recently updated to reflect this information.
More cases of blood clots in Europe have since arisen and most of the cases occurred within 14 days of receiving the AstraZeneca shot, with the majority in women under the age of 55 according to Dr. Caroline Quach-Thanh, the chair of NACI.
The new data from Europe suggests the risk of blood clots is approximately one in 100,000, which is significantly higher than the one in one million risk initially suggested. Also, the fatality rate among those who develop clots is as high as 40%.
The rare cases that are being seen in some AstraZeneca recipients are called Vaccine-Induced Prothrombotic Immune Thrombocytopenia (VIPIT), which can cause death but can also be treated if caught early, NACI said.
Health Canada says to date, no cases of these events have been reported in Canada. “However, through our ongoing international collaboration, Health Canada has become aware that additional cases of these events have been reported in Europe.”
Quach-Thanh, also said older Canadians should take whatever vaccine they can get because contracting COVID-19 poses a much greater health risk to them than the outside chance of developing this sort of blood clot.
In light of the “evolving information,” Health Canada is also issuing additional terms and conditions on the authorizations of the AstraZeneca and Verity Pharmaceuticals/Serum Institute of India vaccines. These will include a requirement that the manufacturers conduct a detailed assessment of the benefits and risks of the vaccine by age and sex in the Canadian context. This information will support the ongoing evaluation of these rare blood clotting events, and allow Health Canada to determine if there are specific groups of people who may be at higher risk. Health Canada has been in discussions with AstraZeneca on this evolving issue.
Health Canada says it will assess this information when it is received and will determine if additional regulatory actions are necessary. Health Canada will continue to work collaboratively with its international counterparts to collect and assess information.
Health Canada’s guidance issued to healthcare practitioners last week still stands, and provides vaccine recipients with information on the signs and symptoms to monitor for following vaccination.
Meanwhile, on Tuesday Canada is expecting to receive 1.5 million doses of the AstraZeneca vaccine from the U.S. where the vaccine has yet to be approved.