January 11, 2013

Group Health researchers find flu vaccine is working

CDC advises vaccination for all, plus antiviral treatment for very sick and high-risk people with flu symptoms

Seattle, WA—Is the flu vaccine working? It is 62 percent effective in preventing the flu this season, according to a study by the Centers for Disease Control and Prevention (CDC) involving Group Health and four other sites around the country.

>Michael L. Jackson, PhD, MPH“That level of effectiveness is typical for flu vaccine during seasons when circulating viruses are mostly the same as the viruses the vaccine is designed to protect against,” said Michael L. Jackson, PhD, MPH, an assistant investigator at Group Health Research Institute (GHRI) and a study coauthor. The lead author is his colleague GHRI Senior Investigator Lisa A. Jackson, MD, MPH (no relation).  “While the vaccine isn’t perfect, the study shows that this year’s flu vaccine offers the population substantial benefits in preventing influenza illness and related visits to the doctor. Past studies have shown other benefits of flu vaccination, including reducing illness, doctor visits, time lost from work, and hospitalizations,” he added.

This 2012–2013 season, the influenza season started earlier than usual. But vaccination reduced the risk of influenza-associated medical visits by 62 percent, according to the CDC study, “Early Estimates of Seasonal Influenza Vaccine Effectiveness—United States, January 2013” in the Morbidity and Mortality Weekly Report on January 10. Group Health was one of five sites that conducted evaluations in its medical centers to test the vaccine’s effectiveness: The other four sites are in Wisconsin (Marshfield Clinic), Michigan (University of Michigan), Pennsylvania (University of Pittsburgh Schools of the Health Sciences), and Texas (Scott and White Healthcare).

Flu activity picked up early, especially in the southeast and south-central parts of the country, and it is still on the rise now in Washington state. The CDC recommends that everyone age 6 months and older who has not been vaccinated this flu season get vaccinated, as the flu is likely to continue to circulate for several weeks.

The study of 1,155 children and adults with acute respiratory illness and cough suggests that some people may still get the flu despite having been vaccinated. This could occur if people are exposed to a flu virus that is different from the ones in the vaccine. So far, most viruses analyzed by CDC are like the ones in the vaccine, but there is a smaller proportion of viruses that are different from the ones in the vaccine. Another reason for this is that some people don’t respond as well to vaccination, especially people with weaker immune systems. Because of the possibility that people who have gotten vaccinated may still get influenza, CDC also advises physicians to use antiviral treatment for patients (even those who have been vaccinated) who are very sick (hospitalized patients, for example) and patients who have flu symptoms and are at high risk of complications due to the flu: adults 65 years of age and older, children younger than age 2 years, and adults and children with chronic conditions like emphysema, cystic fibrosis, diabetes, and asthma. A full list of people considered at high risk of serious flu complications is available at http://cdc.gov/flu/about/disease/
. Antiviral treatment includes agents recommended this season, oseltamivir and zanamivir (Tamiflu® and Relenza®).

Group Health has a strong history of research on immunization against infectious diseases, including a Vaccine and Treatment Evaluation Unit (VTEU) and the Vaccine Safety Datalink (VSD) Project.

Group Health Research Institute
Group Health Research Institute does practical research that helps people like you and your family stay healthy. The Institute is the research arm of Seattle-based Group Health Cooperative, a consumer-governed, nonprofit health care system. Founded in 1947, Group Health Cooperative coordinates health care and coverage. Group Health Research Institute changed its name from Group Health Center for Health Studies in 2009. Since 1983, the Institute has conducted nonproprietary public-interest research on preventing, diagnosing, and treating major health problems. Government and private research grants provide its main funding.

Group Health Cooperative
Group Health is one of the nation’s leading nonprofit health systems, recognized for its consumer-governed cooperative origins and innovative solutions for improving care. Established in 1947, Group Health Cooperative, together with its subsidiaries Group Health Options, Inc. and KPS Health Plans, provides health coverage to almost 624,000 residents of Washington state and North Idaho.

More than 400,000 members receive care from Group Health Physicians medical group at Group Health Medical Centers locations across the Puget Sound region and Spokane. Group Health advances health in the community through its medical education, charitable foundation, and nationally recognized research institute.