Ontario will immunize people 65 years of age and older, including those residing in long-term care homes, with seasonal flu vaccine first.

Ontario will offer the rest of the province's population the H1N1 vaccine beginning in November followed by a universal influenza immunization program with the seasonal flu vaccine in the months following. Ontario's decision to take this approach is based on scientific analysis by the province's top immunization experts suggesting that this vaccination sequence strategy will provide the greatest benefit to the population's health.

Vaccine Delivery

Ontario is adopting a phased approach in rolling out two flu immunization programs this year. There will be enough H1N1 and seasonal flu vaccine for all Ontarians who need and want to be vaccinated.

Timing of Flu Shot	Target Population
IMMUNIZATION DURING OCTOBER
Seasonal Flu Vaccine	Persons 65 years and over living in Ontario Residents of long-term care homes
IMMUNIZATION BEGINS IN NOVEMBER
H1N1 Vaccine	Those who would benefit most from immunization and/or those who care for them: People with chronic medical conditions, under age 65 Pregnant women Healthy children from six months to five years old Persons residing in remote and isolated settings or communities Health care workers involved in pandemic response or the delivery of essential health care services Household contacts and care providers of persons at high risk who cannot be immunized or may not respond to vaccines Others who would benefit from immunization include: Adults 65 years of age and over Healthy children five to 18 years of age First responders Swine and poultry workers Healthy adults between 19 and 64 years of age
IMMUNIZATION BEGINS IN DECEMBER/JANUARY
Seasonal Flu Vaccine	Universal influenza immunization program (UIIP) for all people six months of age and older who live, work or attend school in Ontario

Circulating Flu Strains

Based on experience in the southern hemisphere where the pandemic H1N1 flu virus has been dominant, we are anticipating a possible re-emergence of the H1N1 virus in Canada this fall, followed by the circulation of seasonal influenza strains later in the season. Public health officials anticipate that the pandemic H1N1 flu virus will be the predominant strain circulating this fall. Broad flu vaccination in Ontario will be sharply focused on the H1N1 vaccine. 

Flu Vaccine Sequencing

Epidemiological studies show that seniors are most at risk of serious complications, hospitalization and even death from infection with seasonal flu. On the other hand, data shows that infection from the pandemic H1N1 virus does not typically occur in persons over age 60, probably as a result of residual immunity from exposure to H1N1 prior to 1957.

Other population groups are encouraged to delay immunization with seasonal vaccine because some Canadian studies suggest a potential association between prior seasonal influenza vaccination and the risk of acquiring infection with H1N1 flu.

Although these studies are still undergoing further analysis, we want to take a position of precaution.  Ontarians who are neither over 65 years old nor residing in long-term care homes are encouraged to get immunized against the H1N1 flu virus first, followed by seasonal flu vaccination.