Backgrounder: Use of Unadjuvanted H1N1 Flu Vaccine

Who has the unadjuvanted H1N1 flu vaccine been approved for?

The Government of Canada ordered enough adjuvanted H1N1 flu vaccine for all Canadians who need and want it based on WHO advice. We also ordered 2 million doses of unadjuvanted vaccine for pregnant women and very young children.

The additional order of unadjuvanted H1N1 flu vaccine and the latest research which shows unadjuvanted H1N1 flu vaccine to be less effective in young children has resulted in a surplus supply of the unadjuvanted vaccine.

Both the adjuvanted and unadjuvanted H1N1 flu vaccines are safe and effective. The latest research shows both the adjuvanted and unadjuvanted H1N1 flu vaccines provide a strong immune response on average in over 90 per cent of the people who received them in clinical trials. For people between 10 and 64 years of age with healthy immune systems, both the adjuvanted and unadjuvanted vaccines provide an excellent immune response. Unadjuvanted H1N1 flu vaccine is the recommended formulation for pregnant women.

To ensure we keep immunizing people at a brisk pace and continue to build immunity to the virus in communities across the country, we are broadening our recommendations for the use of unadjuvanted vaccine. Specifically, the extra doses of unadjuvanted H1N1 flu vaccine will be made available to healthy people between the ages of 10 and 64 so they can be vaccinated as soon as possible. This will not affect the availability of unadjuvanted vaccine for pregnant women.

Unadjuvanted flu vaccine is not recommended for everyone

For some particular groups, the unadjuvanted vaccine may not provide as strong an immune response. For this reason, it is recommended that the following groups not receive the unadjuvanted vaccine:

• People with weakened immune systems
• Children between 6 months and 9 years of age
• People 65 years of age and older

Get information from your province or territory

Each jurisdiction will continue to target priority groups. Jurisdictions will decide which vaccine will be administered at clinics based on the vaccine supply and the needs in the community, while adhering to the recommendations on who should and should not receive the unadjuvanted vaccine.

To find information on where and when to get vaccinated in your province or territory, click here.

Dosing recommendations for H1N1 flu vaccine