BETHESDA, Md. Children may not need to take a second booster shot for the H1N1 virus — one shot ought to provide adequate protection. The National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health, on Monday reported that early results from a trial testing a 2009 H1N1 influenza vaccine in children looked promising.
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," stated NIAID director Anthony Fauci. "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 vaccine being tested in this trial was manufactured by Sanofi Pasteur in Swiftwater, Pa., in the same manner as its licensed seasonal vaccine, which is used every year in millions of children, and is the same formulation recently licensed by the Food and Drug Administration to protect against 2009 H1N1 influenza. Like inactivated seasonal influenza vaccines, the vaccine contains a purified part of a killed virus and cannot cause flu.