AstraZeneca ‘safe, effective’
Extremely rare risk of blood clots: Health Canada
There is enough evidence to say the Oxford-AstraZeneca vaccine may cause very rare blood clots but the shot is still extremely safe, very effective and will remain on the Canadian market, Health Canada said Wednesday.
The department’s regulatory team is updating the vaccine’s label with information about the possibility of clots but only a patient who developed the new vaccine-induced blood clotting syndrome is advised not to get another dose of it.
“Health Canada still considers the benefits of the AstraZeneca vaccine to outweigh the risks of getting COVID-19,” said Dr. Supriya Sharma, the chief medical adviser at Health Canada who manages COVID-19 vaccine regulation. “We are not limiting the use of the vaccine to any specific age group or sex.”
The National Advisory Committee on Immunization, which recommended March 29 that AstraZeneca not be used on patients under 55, will now meet to decide if that advice should be updated. NACI issued a statement Wednesday saying it will update the guidance “soon” but for now the age recommendation stands.
The U.K. regulator recently said, like Health Canada, that the vaccine remained safe for everyone, but the British version of NACI recommended it not be given to people under 30, who have the lowest risk for severe illness from COVID. Denmark on Wednesday became the first country to decide to stop using AstraZeneca entirely.
The clotting syndrome has been labelled VIPIT, short for vaccine-induced immune thrombotic thrombocytopenia. It occurs when the body’s immune system begins to attack blood platelets, leading to clots, and is treatable. Canada has had one VIPIT case reported — a Quebec woman older than 55.
International reports show anywhere from one clot reported for every 40,000 doses given in Denmark, to one in 100,000 in Germany, and one in 250,000 in the U.K.
“These are extremely, extremely rare,” Sharma said. “The risk of ... regular clots with COVID is much, much, much higher.”
COVID-19-caused clots are not the same as those caused by VIPIT, but one in five patients hospitalized with COVID-19 will develop a clot, and for patients in critical care, the risk is one in three.