Ten New Brunswickers have had "serious" reactions after getting the COVID-19 vaccine, as of April 3, says the Department of Health.
Nearly 105,000 people had received at least one dose by that time, according to the New Brunswick COVID-19 dashboard.
That puts the incidence at roughly 0.01 per cent.
An event is considered serious if it:
Results in death.
Is life-threatening, such as anaphylaxis, a severe allergic reaction.
Requires in-patient hospitalization or prolongation of existing hospitalization.
Results in persistent or significant disability/incapacity.
Results in a congenital anomaly/birth defect.
Department of Health spokesperson Bruce Macfarlane said he could not disclose which vaccines were involved as the incidents are still under investigation.
Three vaccines are currently in use in New Brunswick: Pfizer-BioNTech, Moderna and AstraZeneca-Oxford.
Macfarlane would not provide any details about the nature of the reactions, or any other related information, such as the geographic location, details about the patients, or dates, citing the ongoing investigations.
Sixty-three people, or 0.06 per cent, have had "non-serious" adverse events, he said.
This type of event, examples of which include soreness at the site of injection and slight fever, represent the majority of reports across Canada, according the Public Health Agency of Canada.
A total of 2,668 non-serious adverse events have been reported nationally, as of April 2. That's 0.05 per cent of the 5,897,445 doses administered.
"The benefits of vaccines authorized in Canada continue to outweigh the risks," the government website states.
Obligated to report reactions
Under the Public Health Act, health-care providers who administer vaccines or provide clinical care for clients are required to report in writing any adverse events following immunization to their regional medical officer of health, said Macfarlane.
An adverse event is defined by the Public Health Agency of Canada as "any untoward medical occurrence which follows immunization." It isn't necessarily causally related to the usage of the vaccine.
The adverse event may be any:
Unfavourable or unintended sign (for example: skin rash).
Abnormal laboratory finding.
Serious events must be reported within one working day of their occurrence, and other events "with less severity," within five working days, said Macfarlane.
Examples of these less severe events include seizures, associated events where medical attention is required, events where consideration must be given to postpone future immunizations, and "unexpected events with no alternative explanation," according to a Department of Health information poster.
Minor or expected reactions, as outlined in the product monograph, such as injection site reactions that last less than four days and fever, do not need to be reported, unless they are more severe or more frequent than expected, according to the poster.
The forms reporting the adverse events following immunization are entered into a Public Health database that is monitored daily with "special attention to serious or unusual events that could signal a concern regarding vaccine safety," Macfarlane said in an emailed statement.
Regular meetings to review data
"All adverse events are flagged and investigated. All serious events undergo medical review to see if there are any safety issues needing further action and determine the potential for a linkage with vaccination."
This includes meeting regularly to review the data with provincial and territorial partners, the regulator, research networks and medical advisers "to ensure there are no safety issues that require action," said Macfarlane.
"Any unexpected safety concerns are detected quickly and acted upon immediately."
All provinces have an agreement to share their adverse events reports with the Public Health Agency of Canada. The agency enters the reports into the Canadian Adverse Event Following Immunization Surveillance System to "flag signals" of adverse events and to "inform vaccine safety decisions nationally," he added.