Scientists prepare to test vaccines to protect against new bird flu strain

Group Health Research InstituteSep 19 2013

Group Health helps protect people from deadly flu seen in China last spring

Scientists at Group Health Research Institute are preparing for the potential pandemic spread of a new bird flu strain that caused severe disease in China earlier this year, joining researchers from seven other Vaccine and Treatment Evaluation Units funded by the National Institutes of Health (NIH) to test vaccines to protect against the illness in adults.

"Influenza viruses are constantly changing, and there is always a threat of a next pandemic," said Lisa Jackson, MD, MPH, a senior investigator at Group Health Research Institute and principal investigator of one of the two national research studies of this strain. "The new H7N9 strain that caused an outbreak in China earlier this year has not circulated in people, so we have no pre-existing immunity to it."

The vaccine includes proteins from the virus but cannot transmit influenza.

"Seattle is a 'gateway to the Pacific,'" Dr. Jackson added. "If this new strain of the influenza virus travels to the United States, Seattle is likely to be at risk, so it is important for us to be prepared. And whether or not the H7N9 influenza spreads to the United States in the future, our research will teach us a lot about how to protect ourselves from the next pandemic."

Dr. Jackson is a member of the team of infectious diseases researchers whose work will help shape public health policy and create influenza immunization plans to protect Americans should there be an outbreak of H7N9 (bird) flu.

The new bird influenza strain was first detected in 135 people, most of whom had contact with poultry, in China last spring. Most people had severe respiratory infections, and 44 people-or 32 percent of those who were ill-died. While the median age of those stricken with the H7N9 flu was 58, four cases were confirmed in children.

Health authorities are preparing for possible H7N9 flu re-emergence during the normal flu season when the weather turns cooler, and for further virus mutation that might make it more easily transmitted between people.

"While the virus has not been detected in the United States and is not easily spread between people, public health officials are concerned the virus might change to become very contagious between people, which could trigger a global outbreak," said Dr. Jackson. "Should that occur, we need to be prepared with a vaccine to protect people from illness."

Pandemics happen when people don't have immunity to a new strain of influenza, which allows it to spread quickly. The last pandemic occurred in 2009 with the spread of H1N1 influenza, which originated in pigs and spread to people.

Typically, vaccines are the first line of defense against influenza. Within two or three weeks of getting a flu vaccine, the body mounts an immune response by making antibodies that fight the flu virus. Those who are vaccinated may not get sick if they are exposed to influenza or may have a much milder or shorter case of the illness.

"We know how to prevent flu with vaccine, and this study is designed to help us fine-tune the process," Dr. Jackson said. "We're studying how much active ingredient we need to put into the vaccine and if we can accelerate the process with a substance that improves the immune response."

The study being conducted at Group Health will recruit up to 1,000 adults nationally, who are age 19-64 years old and in good health. Study participants will receive different dosages of an investigational vaccine given with and without one of two adjuvants, which are substances added to a vaccine to increase the body's immune response.

Scientists will gather safety data to better understand the benefits and risks of this investigational vaccine and learn about its ability to trigger an immune response.

Eight Vaccine and Treatment Evaluation Units (VTEUs), which are funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the NIH, will participate in trials to investigate an H7N9 influenza vaccine. In addition to the VTEU at Group Health, other sites include Baylor College of Medicine, Houston; Children's Hospital Medical Center, Cincinnati; Emory University, Atlanta; University of Iowa, Iowa City; University of Maryland, Baltimore; Saint Louis University, St., Louis; and Vanderbilt University, Nashville. Additionally, the University of Texas Medical Branch in Galveston will be conducting the trial as a subcontractor to Baylor College of Medicine.