# 4031
Earlier today Dr. David Butler-Jones, Chief Public Health Officer in Canada, held a press conference where he described the number of adverse side effects from the pandemic vaccine as being less than normally seen with seasonal flu vaccines (see Canada Reports On H1N1 Vaccine Safety).
Tonight, the Public Health Agency of Canada has put up a detailed report on their vaccine surveillance efforts through November 7th.
Weekly Vaccine Surveillance Report
The Public Health Agency of Canada and Health Canada, with the collaboration of provinces and territories, the Canadian Paediatric Society and a network of researchers is actively monitoring serious adverse events following immunization to the H1N1 flu vaccine in Canada. This is a key component of the Government of Canada approach to ensuring vaccine safety.
An adverse event following immunization (AEFI) is any unwanted medical reaction following immunization. Reporting an adverse event does not mean that the vaccine caused harm. Careful investigation is needed to determine if the events are linked or if they are coincidental.
The majority of adverse events are minor reactions – like soreness at the injection site, or a slight fever – but sometimes, more serious adverse events (SAE) are reported. Serious adverse events are reactions that cause life-threatening illness, hospitalization, disability or death, like a severe allergic reaction, paralysis, or a seizure.
Serious adverse events following immunization are rare. In any immunization campaign, from regular childhood vaccines to seasonal flu shots, the average reported rate of serious adverse events is about one case for every 100,000 doses distributed. For more information, visit our vaccine safety and surveillance Frequently Asked Questions.
Immunization programs for the H1N1 flu virus began the week of October 26, 2009 in Canada. There are three types of vaccine authorized for use in Canada:
- Arepanrix (adjuvanted H1N1 flu vaccine from GlaxoSmithKline)
- Unadjuvanted H1N1 flu vaccine from GlaxoSmithKline
- Panvax (unadjuvanted H1N1 flu vaccine from CSL Australia)
This page will be updated weekly and provides a cumulative update on the adverse events following immunization reported the previous week.
Cumulative Trends as of November 7, 2009:
- To date, the reporting rates for all adverse events as well as serious adverse events are within the range of that observed following seasonal flu vaccine. For most vaccine campaigns, one serious adverse event occurs for every 100,000 doses distributed.
- All adverse events reported during this time period were observed following immunization with Arepanrix, GlaxoSmithKline’s adjuvanted H1N1 flu vaccine. No unadjuvanted vaccine was administered during this time period as it was not delivered to provinces and territories until November 8, 2009.
- The most frequently reported events were minor and included nausea, dizziness, headache, fever, vomiting and injection site reactions.
- There were several reports of allergic reactions consisting of a variety of symptoms and signs including hives, swelling, redness or rash on the skin, tingling of the lips or tongue, a tightness in the throat and/or difficulty breathing, and nausea. These have onset mostly within minutes of immunization and have been treated promptly by clinic staff.
- The 36 serious adverse events included several reports of febrile seizures (a seizure brought on by high fever) and anaphylaxis. Anaphylaxis is a severe allergic reaction that can be life threatening. One of the reported cases of anaphylaxis has been fatal and is being investigated. To date the frequency of anaphylaxis is less than 1 event per 100,000 doses distributed and thus does not exceed what is seen with other vaccines.
- The adverse events reported thus far are consistent with what was seen in clinical trials, and what has been seen in other countries where the adjuvanted vaccine is being used.
*Please note that the first reporting period covers two weeks. Cumulative reports will be made on a weekly basis ongoing.
Cumulative doses distributed, adverse events and serious adverse events reported from Wednesday, October 21, through to Saturday, Nov 7, 2009
