<p>FDA licensed (approved) several formulations of the 2009 H1N1 influenza vaccines, including multi-dose vials and single-dose units. Multi-dose vials contain thimerosal as a preservative to prevent potential contamination after the vial is opened</p> <p>Some vaccine manufacturers are producing 2009 H1N1 influenza vaccines in single-dose units, which do not require the use of thimerosal as a preservative. In addition, the live-attenuated version of the vaccine, which is administered intranasally (through the nose), is produced in single-units and does not contain thimerosal.</p> <p>For additional information about the FDA approval of the H1N1 flu vaccine, see <a href="http://www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm181950.htm">http://www.fda.gov/BiologicsBloodVaccines/Vaccines/ApprovedProducts/ucm181950.htm</a></p> 2009-09-15T14:09:21-04:00 false 4168 Does the 2009 H1N1 influenza vaccine contain thimerosal? 2009-12-16T19:54:00-05:00 2009-12-16T14:54:26-05:00 1