Vaccine research specialists with University of Iowa Health Care, in collaboration with colleagues across the country, are preparing for the potential pandemic spread of a new bird flu strain (H7N9) that caused severe disease in China last spring. The UI team and researchers from the seven other NIH-funded Vaccine and Treatment Evaluation Units will test vaccines to protect against the illness in adults.
"The H7N9 strain has never circulated in human populations so our immune systems are not primed to respond to this virus," says Patricia Winokur, M.D., UI professor of internal medicine, director of the University of Iowa Vaccine Research and Education Project, and principal investigator of the vaccine study at the UI. "This means that if this virus can acquire the ability to spread from human to human, the world population would be very vulnerable and a pandemic with high mortality could ensue."
Flu pandemics occur when a new strain of influenza spreads quickly through a population that lacks immunity to that strain. The last pandemic occurred in 2009 with the spread of H1N1 influenza, which originated in pigs and spread to people.
The new avian influenza strain was first detected last spring in China in 135 people, most of whom had contact with poultry. Most affected people had severe respiratory infections, and 44 people – approximately one third of those who were ill – died. While the average age of those affected with the H7N9 flu was 58, four cases were confirmed in children.
So far, no cases of H7N9 have been detected outside of China. However, health authorities worldwide are preparing for possible H7N9 flu re-emergence during the normal flu season when the weather turns cooler, and for further virus mutation, which could allow the virus to be more easily transmitted between people.
The new study will test the safety and effectiveness of a new vaccine against H7N9 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.
"Unfortunately, we know from past studies that humans just do not mount a very strong immune response to H7 strains of influenza, even after using much more potent strengths of vaccine," Winokur says. "So in this study, we will be adding an adjuvant to the vaccine to try to jump-start the immune response to make more antibodies that would protect people better."
Winokur notes another advantage to using adjuvants – substances added to a vaccine that increase the immune response – is that smaller doses of the influenza proteins can be used in the vaccine. This means more doses can be created and larger numbers of people around the country can be vaccinated.
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.
The researchers 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.
"I can say without a doubt, that the University of Iowa has stepped up and pushed our system to respond incredibly quickly to this challenge. I also know that our volunteers will step up to the plate and help us get the information that the country needs," Winokur adds. "The individuals who volunteer for these types of studies are the backbone to our entire clinical trials program and they make Iowa an amazingly successful place to do this type of work."
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 the UI, the VTEU sites are Baylor College of Medicine, Houston; Children’s Hospital Medical Center, Cincinnati; Emory University, Atlanta: Group Health Cooperative, Seattle; St. Louis University, St. Louis; 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.
Further information about both clinical trials can be found at ClinicalTrials.gov.
To learn more about the vaccine research being conducted at UI Health Care, call 319-356-4848, or visit our Vaccine Research & Education Unit webpage.