Swine Flu Vaccine in Children
Preliminary Efficacy of H1N1 Flu Shots for Children Reported
Oct 4, 2009
Children have little natural immunity to the swine flu, making them particularly susceptible to the virus. The FDA has approved four vaccines for the prevention of swine flu, and preliminary reports suggest that they are safe and effective in adults. A recently released report now describes the efficacy of the H1N1 vaccine in children.
Studies Testing Swine Flu Vaccination in Children
Two clinical trials have been designed by The National Institute of Allergy and Infectious Diseases to evaluate swine flu vaccination in children ages 6 months to 17 years. The first study is assessing two strengths of the H1N1 vaccine manufactured by Sanofi Pasteur. This swine flu vaccine contains inactivated (killed) H1N1 virus and is delivered to the participants via injection. The trial will enroll up to 650 children at five locations. Participants will receive a first dose of either 15 or 30 milligrams of H1N1 vaccine and a second dose three weeks later. Blood samples will be taken to determine how the childrens' immune systems respond to the vaccine.
The second trial is testing the combination of Sanofi Pasteur's swine flu vaccine with a licensed seasonal flu vaccine. The trial is also enrolling 650 children, and will determine how immune responses vary when the H1N1 vaccine is given before, after or at the same time as the seasonal flu vaccine.
Approved H1N1 Vaccine is Effective in Children
Preliminary results from the trial that is evaluating two dosing strategies for the H1N1 vaccine in children have been released. These results show that one 15 milligram dose of swine flu vaccine generates an immune response that is expected to protect against the H1N1 virus in 76% of children 10 to 17 years old 8 to 10 days following vaccination. This response is comparable to what has recently been reported in the swine flu vaccine trials in adults. It appears likely that children in the 10-17 year old age group will only require a single vaccination for the swine flu.
Only 36% of children ages 3 to 9 that received one 15 milligram dose of swine flu vaccine experienced an immune response that would be protective against the virus, and only 25% of children ages 6 months to 35 months old showed a strong immune response after a single 15 milligram dose of H1N1 vaccine. This response in younger children is similar to what is seen with seasonal flu vaccination. It is likely that children within the 6 month to 9 year old age group will need to receive two doses of swine flu vaccine to be fully protected against the virus.
As the trials that are investigating the swine flu vaccine in children mature, more information regarding effective dosing and safety will be available to the public. In addition, ongoing studies are investigating the safety and efficacy of H1N1 vaccination in other high risk groups, like pregnant women.
References
The National Institutes of Health: "Early Results: In Children, 2009 H1N1 Influenza Vaccine Works Like Seasonal Flu Vaccine"
Clinicaltrials.gov: NCT00944073; NCT00943202
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