The candidate vaccine being tested in this study is manufactured by the same method used to make the seasonal-influenza vaccine. All of the participants in the Stanford study will receive the vaccine, although at different doses and with or without the adjuvant. Subjects will be randomly assigned to one of five different groups. Three groups will get different doses of the H1N1 virus vaccine combined with adjuvant. The two other groups will receive the higher doses of vaccine, but no adjuvant. Neither the volunteers nor the study staff will know which vaccine dose or combination was given to whom until the end of the study. The adjuvant used in this study has been tested with other influenza vaccines in more than 12,000 persons, but this will be the first time it is given combined with this particular vaccine.

The spread of the pandemic H1N1 influenza strain is expected to kick into higher gear this fall as children transmit the virus to one another in school. Meanwhile, the federal government is awaiting word from trials already under way before making a final decision about whether to proceed with a large-scale national immunization program.

The government, which had hoped to have 120 million doses of the H1N1 vaccine on hand by Oct. 15, announced on Aug. 18 that, because of delays in the manufacturing process, it now expects only 45 million doses to be available by then.

Clearly, innovations that might increase the vaccine ™s potency would be helpful, Dekker said. An adjuvant that can boost overall immune response is potentially dose-sparing: Its inclusion in a vaccine may render the vaccine potent in smaller doses, stretching tight supplies to cover more people. Dekker said data from this trial will help the U.S. government determine whether to include an adjuvant in the vaccine in order to stretch tight supplies or to boost the immune response.

med.stanford