Single Dose Pandemic Vaccine Effective

A Maryland firm said Thursday that a single dose of bird flu vaccine, plus a patch, was effective in 73 percent of trial subjects.

The 500-subject trial of the Iomai Corp.’s immunostimulant adjuvant patch used with an injected vaccine for H5N1 influenza was sufficient to provide an immune response considered protective in 73 percent of those tested — a statistically significant improvement over those who received the H5N1 influenza vaccine alone.

This is one of the first trials to demonstrate that a single dose of pandemic influenza vaccine may meet the level of protection suggested in U.S. Food and Drug Administration guidance — an immune response level considered protective in 70 percent or more of vaccine recipients, Stanley C. Erck, president of Iomai, said.

The only FDA-approved vaccine in the United States for the avian influenza H5N1 virus requires two 90-microgram doses, administered 28 days apart, to be effective in equal to or greater than 40 in 44 percent of vaccinated individuals.

During an influenza pandemic, public health officials will face two large hurdles — limited vaccine stocks and the logistic difficulty of administering two vaccinations over a period of several weeks, Erck said in a statement.