Friday, March 16, 2018
As the U.S. suffers through this year’s severe bout of seasonal flu, Cincinnati Children’s is part of a national effort to prevent a global pandemic of another type of influenza – the H7N9 strain of avian flu spreading with growing alarm in regions of China.
Cincinnati Children’s is one of nine Vaccine and Treatment Evaluation Units (VTEU) under contract with the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health (NIH). The medical center is collaborating on one of two Phase 2 nationwide clinical trials to evaluate a new vaccine for H7N9.
Concerns about H7N9 avian flu are related but still very separate from the current seasonal flu, according to Paul Spearman, MD, Director of Infectious Diseases at Cincinnati Children’s and lead investigator of the study’s Cincinnati arm. Unlike avian flu strains, seasonal flu in the U.S. does not come from poultry.
China is currently experiencing its sixth outbreak of H7N9 since avian flu was first reported in humans in 2013, with a cumulative total of 1,567 human infections, according to the World Health Organization. The H7N9 strain causes severe respiratory illness and has a high mortality rate, killing 39 percent of those infected, Spearman said.
So far transmission of H7N9 has mainly been between birds and humans or through human exposure to environments contaminated by birds. No H7N9 influenza viruses have been found in people or in birds in the United States. However, U.S. health officials are watching closely to see if avian flu strains like H7N9 mutate genetically, which could make them more easily transmissible between humans.
In the meantime, they are working on safe and effective preventive vaccines, which Spearman said is much in need and would help save lives if a severe outbreak or pandemic occurs.
“The concern is this is the largest epidemic of avian flu to date in China, and potentially it could spread outside of Asia,” Spearman said. “If the H7N9 strain mutates and develops the capacity to spread easily from person-to-person it could cause a widespread epidemic, or pandemic.”
Although H7N9 transmission to humans has so far been through direct exposure to infected poultry or contaminated environments, NIAID officials said because it’s a newer virus, humans would have little to no immunity in a widespread outbreak.
NIAID has already funded other studies on a predecessor to the new 2017 H7N9 IIV vaccine candidate. The new 2017 version of the vaccine is an A/H7N9 inactivated influenza vaccine candidate developed by Sanofi Pasteur. Some subjects this year will receive along with vaccine an adjuvant made by GlaxoSmithKline Biologicals called AS03. This is being done to see if the adjuvant can boost the immune response to the vaccine.
Adults who enroll in the clinical trial will not be infected with H7N9 bird flu. Researchers will test people who receive the vaccine to see if it successfully stimulates a strong and sustained immune response. This is accomplished by seeing whether the vaccine recipient’s immune cells produce specific antibodies that are known to attack molecules called antigens that are specific to H7N9.
Cincinnati is enrolling 40 adults between ages 19 and 64 as part of the Phase 2 clinical trial. Overall, this study will also include 150 patients with VTEU sites in Birmingham, Ala., Baltimore and Nashville. People interested in enrolling in the Cincinnati arm of the study should call 513-636-7699.
This trial will test the H7N9 vaccine with AS03 adjuvant in conjunction with the quadrivalent seasonal influenza vaccine, according to NIAID officials. By administering the vaccine candidate to some volunteers who have received the seasonal influenza vaccine, and some who have not, investigators will be able to learn if the H7N9 vaccine affects the immune response to the seasonal influenza vaccine.