Updated Results: In Youngest Children, a Second Dose of

H1N1 vaccines have been tested in children volunteers to determine if an additional dose would be beneficial to its recipients. Preliminary results released in september were based on the volunteers recieving a single 15-microgram dose of the vaccine. Children 10 years and older had great results in regarding the immune response. The vaccine was tested again and the volunteer children were given an additional 15-microgram dose (recieved (2) 15-microgram doses). There was no increase in the immune response 10 days out with the 10 year olds and older but children 9 years old and younger showed significant increase in their immune response making it clear that a second dose is beneficial in preventing infection.