Health care workers have administered more than two million doses of COVID-19 vaccines in Toronto, the city announced on Saturday, as officials continue to urge residents to get the shot.
"We are doing everything we can as a city government to get every resident vaccinated," Toronto Mayor John Tory said in a statement. "Getting vaccinated as soon as possible is the right thing to do so that we can bring this pandemic to an end."
As of Friday evening, about 739,669 people have booked COVID-19 vaccination appointments at a city-run clinic.
A medical expert, meanwhile, told CBC Toronto that the number of adverse events following immunization in Toronto and Ontario shows that COVID-19 vaccines are "incredibly" safe.
Dr. Sarah Wilson, a public health physician at Public Health Ontario (PHO), said vaccine safety monitoring is an important part of vaccine programs and is done for all vaccines.
"In the context of COVID-19 vaccines, I think it's obviously very important given the number of individuals we're vaccinating," Wilson said.
COVID-19 vaccines are new vaccines, she added. "We're still learning about these vaccines and it's really important for us to be able to understand the safety of these vaccines outside of clinical trials and in the real world setting."
Toronto has had 527 adverse events after immunization
There have been 527 reports of adverse events in Toronto in the last five months, according to Public Health Ontario, in a weekly report. Each report represents one person who received a COVID-19 vaccine and had at least one adverse event.
The 572 reports are out of a total of 3,569 adverse event reports received following the administration of 8,069,397 doses of COVID-19 vaccines to date in Ontario, the report says. Of the total, 3,429 are considered non-serious, or 96.1 per cent, while 140 meet the definition of serious, or 3.9 per cent.
"I think it actually shows how incredibly safe these vaccines are as part of the COVID-19 vaccination program," Wilson said.
Ontario defines adverse events as "any untoward medical occurrences that followed immunization." The event happens after a person is vaccinated, but does not necessarily mean it was caused by the vaccine.
Allergic skin reactions as well as pain, redness and swelling at the injection site are the most commonly reported adverse events, the report said. These adverse events represent 26.4 per cent and 24.9 per cent, or more than 50 per cent, of the total number of reports, respectively.
"Most people would regard them as being what might be expected to some degree after vaccination," Wilson said.
She said more than 8 million doses of COVID-19 vaccines have been administered in the province. Of that number, 0.04 per cent of those immunizations — "a very small number" — have resulted in an adverse event.
More women report adverse events than men
The number of adverse events in Toronto, 527, compares with 287 in York Region and 227 in Peel Region. Toronto has the largest number of reports of any health unit in Ontario.
As well, 2,912 adverse events reported to date in Ontario involve women, while 585 adverse events reported involve men. PHO has just begun to track adverse events among people aged 12 to 17 years.
Health care providers, or vaccine recipients themselves, report adverse events to public health units, which in turn report the events to PHO. All of the events are investigated and summarized in a provincial database.
PHO then presents the information in a weekly report and shares it with the Public Health Agency of Canada.
A total of 143 reports which PHO says were "managed as anaphylaxis" have been received, of which 13 meet the definition of serious. Anaphylaxis is a severe allergic reaction.
The report said 113 reports include a COVID-19 vaccine-specific adverse event of special interest, in which 56 reports meet the serious definition.
An adverse event of special interest is defined by Health Canada as "pre-specified medically significant event that has the potential to be causally associated with a COVID 19 vaccine product."
Ontario has had 16 reports of rare blood clots known as thrombosis with thrombocytopenia syndrome (TTS) after people received the AstraZeneca vaccine. Thirteen of these cases are considered to be vaccine-induced immune thrombotic thrombocytopenia (VITT).
One person, a man in his 40s, who had VITT died weeks after he was vaccinated in late April. The exact cause of his death is being investigated. PHO has declined to say in which region the man lived in Ontario.
Toronto Public Health sets up team to track adverse events
Toronto Public Health (TPH), for its part, has set up a team to track adverse events following immunization involving COVID-19 vaccines.
The team, set up in December 2020, consists of a public health physician, a manager, two clerical staff, and 15 public health nurses, 10 of which were added at the end of March 2021.
Dr. Vinita Dubey, associate medical officer of health for TPH, said all health care providers who administer vaccines must report such events. It is required under Section 38 of the Health Protection and Promotion Act and Regulation 569.
"In Ontario, local public health units are required to investigate reports of adverse events related to all vaccines, including COVID-19 vaccines, to provide recommendations to individuals who have experienced an adverse event and their family physicians regarding the safety of further doses, and to provide adverse event data to the province via their surveillance system," Dubey said.
The collection of information is how the provincial and federal governments monitor vaccine safety, she said.
After people receive a COVID-19 vaccine, they may experience side effects and the majority will last from one to three days. The most common side effects include a sore arm, headache, fatigue, muscle or joint pain, fever, chills, nausea or vomiting.
Dubey said some side effects, including fever, are more common after the second dose of the mRNA vaccines, but not with the AstraZeneca vaccine.
Some side effects indicate vaccine working
"These types of side effects are expected and simply indicate the vaccine is working to produce antibodies that provide protection against COVID-19," Dubey said.
People who have received COVID-19 vaccine are advised to seek medical attention if they have any unusual symptoms, or symptoms that last longer than three days after vaccination. Dubey said they should call 911 if they need immediate care, or should speak with their health care provider, or call TPH.
Dubey said it's important to remember that Health Canada authorizes vaccines when there has been enough scientific and clinical evidence to show that they are safe, effective and manufactured to the highest standards. She said vaccines that are being used in Canada have been manufactured at plants around the world that meet these standards.
"There are several systems in place to monitor the vaccine's safety before, during and after the vaccine has been licensed," Dubey said.