Early results from a trial testing a 2009 H1N1 influenza vaccine in children look promising, according to the trial sponsor, the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Preliminary analysis of blood samples from a small group of trial participants shows that a single 15-microgram dose of a non-adjuvanted 2009 H1N1 influenza vaccine – the same dose that is in the seasonal flu vaccine – generates an immune response that is expected to be protective against 2009 H1N1 influenza virus in the majority of 10- to 17- year-olds eight to 10 days following vaccination. These results are similar to those recently reported in clinical trials of healthy adults. Younger children generally had a less robust early response to the vaccine.
"This is very encouraging news," says NIAID Director Anthony S. Fauci, M.D. "As we had hoped, responses to the 2009 H1N1 influenza vaccine are very similar to what we see with routinely used seasonal influenza vaccines made in the same way. It seems likely that the H1N1 flu vaccine will require just one 15-microgram dose for children 10 to 17 years of age. The 2009 H1N1 influenza virus is causing widespread infections among children, so these are welcome results."
The ongoing NIAID-sponsored trial began in mid-August at five sites nationwide. The trial is assessing the safety and immune responses to one and two doses of either 15 micrograms or 30 micrograms of vaccine. Data from the trial is being compared for three age groups: children 6 months to 35 months old; 3 to 9 years old; and 10 to 17 years old.