Marc Berthiaume, director of Health Canada’s office of medical sciences, said the issues reported by a U.S. federal health agency on Monday were related to the product’s published efficacy rate, not its safety in use. Berthiaume said Health Canada’s decision to clear the product was not based on any of the clinical trial information that U.S. officials are currently reviewing. He said Canada had based its endorsement largely on data from AstraZeneca trials in the UK and Brazil, and on studies published in countries where the shot had been used for some time.
“I think it would be alarmist to suggest that the results of additional clinical trials could lead to a change in the approval status of AstraZeneca here in Canada,” said Berthiaume.
“The additional information that has been gathered in the United States will be sent to Health Canada in the coming weeks. If there is a need to readjust, we will do it later with Canadians.
Millions of people have received the AstraZeneca vaccine worldwide, including more than 17 million in Britain and the European Union – almost all without serious side effects.
Health Canada “concerned” by vaccine hesitancy
Dr. Supriya Sharma, Chief Medical Advisor for Health Canada, said American questions about the rate of effectiveness did not change anything for Canadians at this point. She admitted that the headlines about the AstraZeneca gunshot are “something we are concerned about” because they may make some Canadians reluctant to get vaccinated.
“We’ve said it time and time again – that even the most effective vaccine only works if people trust it and are willing to receive it,” she said.
“It’s like any other reputation. Once there is a doubt that seeps into that reputation, it is much more difficult to recover it. The press and concerns around the AstraZeneca vaccine are not helping. ”
WATCH: Health Canada Says Federal AstraZeneca Vaccine Recommendations Not Changing
In a statement released last night, the National Institute of Allergy and Infectious Diseases (NIAID) in the United States said the Data and Safety Monitoring Board (DSMB), which oversees clinical trials, found “outdated information” would have could be reported by the company when it released information yesterday.
The agency said the Anglo-Swedish pharmaceutical giant may have released information that gives an “incomplete view of efficacy data.”
“We urge the company to work with the DSMB to review efficacy data and ensure that the most accurate and up-to-date efficacy data is made public as quickly as possible,” the agency said – without specifying what kind of data could have been. included incorrectly.
The statement came just hours after AstraZeneca released the results of its phase three clinical trials in the United States, which began last August and ended earlier this month. Phase three is the point in a clinical trial where a vaccine manufacturer gathers more information about safety and effectiveness and studies the effect of different doses on various groups.
The company said its COVID-19 vaccine was 79% effective in preventing symptomatic COVID-19 and was 100% effective in stopping serious illness and hospitalization. Investigators said the vaccine was effective for adults of all ages, including the elderly – something earlier studies in other countries had failed to establish.
Use of the product has not yet been authorized in the United States.
Speaking to ABC’s Good Morning America on Tuesday, Dr Anthony Fauci, chief medical adviser to US President Joe Biden and head of NIAID, said the oversight committee was surprised by the better-than-expected efficacy results released. by AstraZeneca.
“They got worried and wrote them a rather stern note and with a copy for me, saying that in fact they felt the data in the press release was somewhat out of date and could in fact be a little misleading,” and wanted them to do it right, ”Fauci said.
Board members rated the vaccine’s effectiveness at between 69% and 74% – up to 10 points lower than what AstraZeneca itself reported – and said the company’s decision to issue a press with better results had served to erode public confidence.
“We told the company that they had better come back with the DSMB and make sure the correct data goes into a press release. ”
In response to the backlash, AstraZeneca said the efficacy figures released yesterday were up to February 17 – a month before the clinical trial ended. In a statement, the company said it would “immediately engage with the independent data security oversight board” and provide the US regulator “with the results of the primary scan within 48 hours.”
This is just the latest public communication problem the company has faced in the past three months.
Earlier this year, a number of European countries halted vaccinations in response to questions about the product’s effectiveness in people over 65, only to restart them after new evidence emerged.
After Health Canada approved the vaccine for all adults, the National Advisory Committee on Immunization (NACI) recommended that the product be used only on people under 65, citing a paucity of trial data clinical studies on the effectiveness of the vaccine in the elderly.
NACI changed course last week after reviewing three “real-world studies” saying the two-dose viral vector vaccine can and should be used in the elderly.
The European Medicines Agency has also had to assure member countries of the European Union that the product is safe to use after reports of post-vaccine blood clots in a very small number of patients.
The agency concluded that the benefits of protecting against COVID-19 – which itself causes bleeding problems – outweigh the risks.
The Public Health Agency of Canada said it was “possible” that the vaccine was associated with “very rare but serious cases of blood clots associated with thrombocytopenia” – a condition associated with very low platelet counts. blood. Health Canada has argued that the benefits of the AstraZeneca COVID-19 vaccine continue to outweigh the risks.