Canada suspends use of AstraZeneca’s Covid-19 vaccine for those under 55
Canadian health authorities have suspended the administration of AstraZeneca’s Covid-19 vaccines to those below the age of 55 years due to growing concerns that the shot could be linked to the formation of blood clots
Canadian health authorities have suspended the administration of AstraZeneca’s Covid-19 vaccines to those below the age of 55 years due to growing concerns that the shot could be linked to the formation of blood clots.
The move followed a recommendation from the National Advisory Committee on Immunisation (NACI).
Health Canada said in a statement the action came in the light of information being reported from Europe about additional cases of “very rare adverse events” of “thrombosis (blood clots) with thrombocytopenia (low blood platelets) occurring after immunisation with the AstraZeneca vaccine”.
Canada has so far received 500,000 doses of the AstraZeneca vaccine, all manufactured by the Pune-based Serum Institute of India (SII) under the Covishield brand name.
The vaccines had arrived in the country on March 3, part of a larger two-million-dose deal that had come into effect after Canadian Prime Minister Justin Trudeau had requested his Indian counterpart Narendra Modi for Covid-19 vaccine supplies during a telephone conversation on February 9.
Canada has so far utilised over 60% of that tranche, which comes to more than 300,000 doses, according to health authorities.
Health Canada, however, clarified that till date “no cases of these events (side effects such as possible blood clots) have been reported in Canada”.
Health Canada is issuing “additional terms and conditions” to SII and its Canadian partner Verity Pharmaceuticals in the Greater Toronto Area. “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,” the agency said in a statement.
The information sought 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 said it is in discussion with AstraZeneca on this “evolving issue”.
“We need to take a pause and look and examine the evolving nature of what’s happening in Europe,” Canada’s deputy chief public health officer Dr Howard Njoo told reporters.
Health Canada also said it “will assess this information when it is received and will determine if additional regulatory actions are necessary”.
Njoo said those who were vaccinated 20 days earlier and didn’t suffer any adverse reaction were safe, but if those more recently administered with the AZ jab suffered such side effects, they should immediately contact their healthcare provider.
NACI said symptoms to be “vigilant” about included shortness of breath, chest pain, leg swelling, persistent abdominal pain, neurological symptoms including sudden onset of severe or persistent worsening headaches or blurred vision and skin bruising other than at the site of vaccination.
In its recommendation announced earlier in the day, NACI said the vaccine “should not be used in adults under 55 years of age at this time while the safety signal of Vaccine-Induced Prothrombotic Immune Thrombocytopenia (VIPIT) following vaccination with AstraZeneca Covid-19 vaccine is investigated further”.
Cases identified in this regard, it pointed out, “have been primarily in women under the age of 55 years; although cases in men have also been reported and have mostly occurred between four and 16 days after receipt of vaccine”.
NACI said that based on information from the European Medicines Agency on March 18, it had earlier been estimated at about 1 per 1 million people, but a higher rate of 1 per 100,000 was reported by the Paul-Ehrlich Institut in Germany this month.
“Decisions” about the administration of a second dose of the AZ vaccine to those below 55 “will be determined based on the latest evidence and research”, the committee said.
