Health Canada says 9 adverse reactions after COVID-19 vaccinations are in line with clinical trials

Health Canada has received nine reports of adverse medical reactions following coronavirus vaccinations in Canada but has seen no evidence of unexpected side effects, federal public health officials said today.

At a news briefing in Ottawa, Canada's Chief Public Health Officer Dr. Theresa Tam said the federal government has launched a new website that will provide weekly reports on vaccine safety.

"As with any new undertaking, we all have questions. These weekly reports on COVID-19 vaccine safety aim to provide Canadians with regular access to credible information that will assist them in making informed and confident decisions on vaccination for themselves and their families," Tam said.

According to the website, nine people reported experiencing a total of 65 symptoms — eight of which were considered severe — as of Jan. 1. All nine people received the Pfizer-BioNTech vaccine.

Vaccinations began on Dec. 14 and, according to data collated by the COVID-19 Data Working group — a volunteer group of academics and data analysts — at least 234,000 doses have administered so far, mostly to front-line healthcare workers and long-term care residents and employees.

Adverse events can range from soreness at the site of injection or a slight fever to more serious issues, such as severe allergic reactions.

Of those who reported serious symptoms, three suffered severe allergic reactions. One patient reported a headache, one reported facial paralysis, one suffered chills, another fainted and one reported pain in extremities.

The most frequent non-serious adverse events reported so far have been swelling at the site of injection, nausea and a sensation of pins and needles, according to the data.

The website notes that not all adverse events experienced by people after receiving a vaccine are necessarily caused by the vaccine.

"The benefits of vaccines authorized in Canada continue to outweigh the risks," the site reads.

No unexpected side effects

Dr. Supriya Sharma is Health Canada's chief medical adviser and is overseeing the vaccine review process. She said there have been no reports of unexpected side effects from patients vaccinated against COVID-19 to date.

"There haven't been any serious adverse events, or even the mild and moderate adverse events, that have been out of line or different than what we've seen in the clinical trials," Sharma said in an interview with The Canadian Press on Friday.

She said experts look to answer two questions when reviewing data after vaccines are delivered. The first is whether anything has happened that was not observed during the clinical trials. The second is whether the side effects documented are more severe, or greater in number, than what the trials saw.

The answer to both questions in Canada so far has been no, said Sharma.

"It seems that the clinical trials are pretty representative," she said.

Canada approved two vaccines against COVID-19 last month. One is made through a partnership between U.S. pharmaceutical giant Pfizer and German biotechnology company BioNTech, while the other is produced by the U.S. firm Moderna.

In both the U.S. and Canada, vaccine recipients are supposed to hang around after the injection in case they experience allergic reactions and need immediate treatment.

Health Canada has advised that people with allergies to any of the ingredients in the Pfizer-BioNTech and Moderna coronavirus vaccines should not receive them and should speak with a health professional about any serious allergies or other health conditions they may have before they receive a coronavirus vaccine.

The regulator continues to review data from two other vaccine developers — British pharmaceutical firm AstraZeneca and Janssen Inc., a subsidiary of Johnson & Johnson — but is still awaiting more data from the companies. Sharma said she can't say when Health Canada would be ready to make a decision about either vaccine.

Both companies are expected to complete Phase 3 clinical trials in the United States this month.