As the supply of H1N1 vaccine for the adult population increases, recent evidence suggests that a new vaccine formulation from an Australian manufacturer may require only one dose for effectiveness in infants and children. CSL, Ltd, of Australia, announced that their 15 mcg antigen formulation (twice the antigen amount in use in the United States at present) resulted in effective antibody levels (immunity) in over 90% of infants and children immunized. Many officials remain concerned about new waves of H1N1 as the winter progresses in the northern hemisphere and then begins later in 2010 in the southern hemisphere. Next year’s routine seasonal flu shots are already scheduled to contain variants of this years H1N1 strain, barring any major mutations in the virus. These modifications are already scheduled to be incorporated into seasonal flu vaccines which will be administered south of the equator beginning in March, April and May. Here in the U.S., concerns about vaccine safety have kept many parents on the sidelines. To be sure, there are always concerns with vaccines, but to date, the H1N1 vaccines appear to have no greater side effect profiles than the seasonal flu vaccines. Health officials are still urging general vaccination of children. Parents of children with special health needs and concerns have been strongly advised to have the receive the vaccine. Parents should discuss this decision with their pediatrician if there are concerns . . .
Australian vaccine maker CSL Ltd (CSL.AX) said on Monday its pandemic H1N1 swine flu vaccine delivered a strong immune response after just one dose in children as young as 6 months. Global health authorities recommend children get two swine flu shots for full protection, but the CSL vaccine showed strong response with just one shot. Australian researchers find that more than 90% of those in study had effective immunity after a single dose, but the 15-microgram dose of antigen is twice that used in the United States.
Study shows one dose of H1N1 vaccine may be enough for children – http://www.latimes.com/features/health/la-sci-swine-flu-vaccine22-2009dec22,0,75
Will One Dose of H1N1 Vaccine Be Enough for Kids? – http://www.time.com/time/health/article/0,8599,1949187,00.html
UPDATE 1-CSL says its H1N1 vaccine effective with 1 dose – http://www.reuters.com/article/idUSN2125173820091221
One Dose of H1N1 Vaccine Enough for Young – http://www.cbsnews.com/stories/2009/12/21/health/main6005618.shtml?tag=cbsnewsLe
Immunogenicity of a Monovalent 2009 Influenza A(H1N1) Vaccine in Infants and Children:… Nolan et al. JAMA.2009; 0: 20091911-10.