Stanford seeks volunteers for flu vaccine study

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 in people of different ages.

Previous flu vaccine studies have shown that following vaccination, children lose their influenza-specific immune response more rapidly than adults. The researchers also know that there is a decline in immune function in the elderly, so they want to look at the differences in how the elderly respond to vaccination compared with younger adults.

The three studies, sponsored by the National Institutes of Health and the Ellison Foundation, will explore several questions about age-related immune response to vaccine, said Corry Dekker, MD, professor of pediatric infectious diseases and the medical director of the Stanford-LPCH Vaccine Program. Whatever they find about the different responses could help design better vaccines or could predict who is at greater risk for developing flu.

Study 1: Comparison of the response to the injected flu vaccine in elderly adults versus young adults, looking at the B cells

The immune response of older adults to influenza vaccine is not always as strong as the response of young adults. By studying the specialized B cells in the blood that make antibodies to flu after vaccination, the researchers hope to learn how age makes a difference. Results from this study may help improve the immune response to influenza vaccine in elderly adults.

Who is eligible : Healthy adults who are 18 to 30 years of age, or 70 to 80 years of age. Volunteers for this study must have had a flu shot (trivalent inactivated influenza vaccine) in the 2006 flu season.

What is required : Three clinic visits over a period of one month. At the first visit, participants will receive a licensed seasonal flu vaccination. A blood sample will be taken at each clinic visit, and participants will be reimbursed $30 for each clinic visit.

Study 2: Comparison of the response to the injected flu vaccine in elderly adults versus young adults, looking at the T-cell and cytokine response

In this study, the researchers will look at the activated T cells that spring into action once the body recognizes invasion by the influenza virus or vaccine. They hope to discover biological markers that could differentiate the immune response to the flu vaccine at different ages, comparing T-cell and antibody responses. Identifying differences in immune function between older and younger volunteers, and among individual volunteers over time may help to predict who is at highest risk for a poor immune response to the flu vaccine.

Who is eligible : Healthy adults who are 18 to 30 and 60 to 100 years of age.

What is required : Volunteers in this study will be followed for up to 3 1/2 years to determine long-term immune responsiveness. Three clinic visits and one phone call are required over a one-month period during the fall flu season. Participants will receive one dose of a licensed seasonal flu vaccine at the first visit. A blood sample will be taken at each of the clinic visits. A phone follow-up will occur six months after the first visit. The series of three clinic visits and the phone call will be repeated in the two following years. Participants will receive $30 reimbursement for each clinic visit.

Study 3: Comparison of the CD4 T-cell immune response to inactivated influenza vaccine in children versus adults

The primary objective of this study is to survey and compare the immune responses of healthy children with those of healthy adults after receiving a flu vaccination. In previous studies, Stanford researchers have demonstrated that children had similar levels of immunity as compared with adults during the first week following flu vaccination; however, the rate of decline in immunity to influenza between 7 to 10 days and one month after vaccination was more rapid for children than adults. This could mean that children might have less protection against influenza toward the end of the flu season. This study will describe the immune responses over two months after immunization to confirm whether this difference persists.

Who is eligible : Healthy children ages 5 to 9 years and healthy adults ages 18 to 49 years.

What is required : Three clinic visits over a period of two months. At the first visit, participants will receive a licensed seasonal flu vaccination. A blood sample will be taken at each clinic visit. Participants will be reimbursed $30 for each clinic visit.

Researchers are particularly interested in recruiting children and the elderly for these studies. For more information about these or other vaccination studies at the Stanford-LPCH Vaccine Program, please call (650) 498-7284, or e-mail Vaccines [email protected]. The full trial descriptions can be viewed at: http://vaccines.stanford.edu/clinical trials.html.

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.