Scientists are preparing for possible pandemic spread of new bird flu strain

Scientists at Saint Louis University are preparing for the potential pandemic spread of a new bird flu strain that caused severe disease in China last spring, 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.

"Because this is a completely novel flu virus, our immune systems have not been exposed to any like it. Consequently, those who contract the H7N9 influenza virus may become very ill, which is why this virus had a fairly high mortality last spring in China," said Sharon Frey, M.D., professor of infectious diseases at Saint Louis University School of Medicine and SLU VTEU principal investigator for one of the national research studies.

"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."

Frey, who is also on faculty at SLU's Center for Vaccine Development, 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 avian 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 such that it becomes 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 Robert Belshe, M.D., a co-investigator and director of Saint Louis University's Center for Vaccine Development, where the research will be conducted locally.

"Should that occur, we need to be prepared with a vaccine to protect people from illness."

Pandemics occur 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. 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," Frey said.

This round of research will recruit up to 1,000 adults nationally, who are 19 to 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 vaccination as well as learn about the ability of the investigational vaccine to trigger an immune response, Frey said.

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 that investigate an H7N9 influenza vaccine. In addition to the VTEU at Saint Louis University, the VTEU sites are Baylor College of Medicine, Houston; Children's Hospital Medical Center, Cincinnati; Emory University, Atlanta: Group Health Cooperative, Seattle; University of Iowa, Iowa City; University of Maryland, Baltimore; 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.

"Ordinarily bird flu is limited to birds but every now and then certain strains make the leap from birds to humans," said Belshe, who is an avian flu expert. "If this strain of avian flu adapts to spread in a highly efficient way from person to person, our research could be critical in protecting public health."