This is a study of two different dose levels of a new formulation of flu vaccine for the 2008/2009 flu season using the World Health Organization recommended virus strains. Subjects will be randomly put into one of three different groups to receive either one or two doses of:
0.25 mL dose of the new flu vaccine, or 0.5 mL dose of the new flu vaccine or the licensed Vaxigrip flu vaccine (control) The parents of the subjects and the study doctor and nurses will not know the group of their child until the study is completed.
The children will be vaccinated with either one dose or two doses depending on whether or not they have received a flu vaccine before. The doctor will decide on the schedule for each child based on the information provided by the parents. The active phase of the study will last approximately two months for children receiving two doses and one month for those receiving a single dose. An extended safety follow-up will continue until Study Month 6.
Two blood samples will be taken from each subject. These will be used to evaluate how well the vaccine works in the children and which dose level works best compared to the control.
The parents will fill in a diary card for four days to record any reactions or symptoms which may occur after vaccination. Parents will also keep a record of other symptoms that may occur between vaccinations and up to six months after the first vaccination and will keep a record of any medication their child takes in this time period.