Adults, Children Needed for Stanford-Packard Flu Shot Studies.

STANFORD, Calif. -- It's the time of year when people start thinking about getting a flu shot, and researchers at the Stanford University School of Medicine and Lucile Packard Children's Hospital are looking for adults and children to participate in three studies that will help them better understand how the flu vaccine works. Two of the National Institutes of Health-sponsored studies are for adults and one is for children.

The flu virus has the ability to outsmart the immune system by constantly mutating, creating a moving target for vaccines. Flu vaccines must be reformulated each year based on which three flu strains experts think will be the most problematic in the coming season. An effective flu vaccine has been available in the United States for more than 50 years, but how it works remains, for the most part, a mystery.

"Influenza is a fascinating virus and it represents a hugely important vaccine challenge," said Cornelia Dekker, MD, medical director of the Stanford-LPCH Vaccine Program. The specter of a potential worldwide flu pandemic that could infect and kill millions of people underscores the need for understanding how the immune systems of children and adults respond to different methods of flu immunization. This knowledge, said Dekker, might lead to the development of more effective flu vaccines.

STUDY 1: Evaluating the potential for using lower doses of flu vaccine

Last year, nearly half of the U.S. supply of flu vaccine was lost when one of the two manufacturers of the injectable vaccine had to withdraw its product due to safety concerns. The researchers want to find out if there are ways of using less of the vaccine while still providing protection against flu illness. If lower doses of the vaccine could be used, vaccine supplies might be able to be stretched out to cover more people at risk.

This study will compare the immune responses and reactions of participants to one of four different doses of Fluzone, the approved injectable flu vaccine. Three different dilutions of the vaccine given under the skin will be compared to the standard dose that is given into the muscle. The vaccine for last year's flu season will be used for the test, but all participants will be offered this year's vaccine at the end of the study.

--Who is eligible: Healthy adults ages 18 to 64.

--What is required: Two visits to the clinic at Stanford during a period of three weeks. Participants will receive one of four doses of Fluzone. A blood sample will be taken at both clinic visits, and participants will be reimbursed $30 per clinic visit. Staff will make a phone call to participants to check on safety between the visits.

--For more information: Call Mary Huang at 650-498-7284.

STUDY 2: Comparing how adults' immune systems respond to two types of flu vaccine

Many Americans now have the option of receiving the flu vaccine as a spray in the nose instead of an injection. FluMist is an attenuated flu vaccine -- created from live virus that has been weakened so that it is no longer infectious -- and was recently approved for use in people between the ages of 5 and 49. Researchers hope to find out whether delivering a flu vaccine through the respiratory system rather than into the muscle makes a difference in the quality of the immune response.

--Who is eligible: Healthy adults ages 18 to 49.

--What is required: Three visits to the clinic at Stanford during a period of four weeks. Participants will be randomly assigned to get either the inhaled FluMist or the injected Fluzone, both approved for the upcoming flu season. A blood sample will be taken at each visit, and participants will be reimbursed $30 per clinic visit.

--For more information: Call Ernesto Gonzalez at 650-736-1574.

STUDY 3: Comparing how children's immune systems respond to two types of flu vaccine

Children are particularly hard hit by the flu, but little is known about how the immune systems of children respond to viral immunization. This study hopes to provide a better understanding of how a child's immune system responds after receiving either injected flu vaccine or nasal spray flu vaccine.

--Who is eligible: Healthy children ages 5 to 9.

--What is required: Three visits to the clinic at Stanford during a period of four weeks. Participants will be randomly assigned to receive either the inhaled FluMist or the injected Fluzone, both approved for the upcoming flu season. A blood sample will be taken at each visit, and participants will be reimbursed $30 per clinic visit.

--For more information: Call Natalie van Venrooij at 650-736-1574.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions -- Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at http://mednews.stanford.edu.