“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

Vitamin D levels in your blood fall to their lowest point during flu seasons. Unable to be protected by the bodys own antibiotics (antimicrobial peptides) that are released by vitamin D, a person with a low vitamin D blood level is more vulnerable to contracting colds, influenza, and other respiratory infections.