“The influenza vaccine and most hepatitis B vaccines are multi-dose vaccines, which contain thimerosal as a preservative” ~ Public Health Agency of Canada - http://www.phac-aspc.gc.ca/im/q_a_thimerosal-eng.php
“The majority of influenza vaccines distributed in the United States currently contain thimerosal as a preservative.” ~ Centers for Disease Control and Prevention - http://www.cdc.gov/FLU/ABOUT/QA/thimerosal.htm

Mercury: Two-thirds of the vaccines made for the 2008–09 flu season contain full-dose thimerosal, an organomercury compound, 49% mercury by weight. It is used to disinfect the vaccine. Each of these flu shots contain 25 micrograms of mercury, a mercury content of 50,000 part per billion, 250 times more than the Environmental Protection Agency’s safety limit. Mercury is a neurotoxin, with a toxicity level 1,000 times that of lead.
Formaldehyde, a known cancer-causing agent is used to inactivate the virus.
Aluminum, added to promote an antibody response,is a neurotoxin that may play …

The following undated information from the Health Canada website describes some of the contents of licensed influenza vaccines in Canada.