Researchers propose gain-of-function experiments on H7N9

Influenza researchers are proposing gain-of-function experiments on H7N9 influenza, an avian influenza subtype that caused more than 130 human infections and 43 fatalities, according to a letter published on Wednesday.

Ron Fouchier, a scientist with the Netherlands-based Erasmus Medical Center, and Yoshihiro Kawaoka, a scientist with the University of Wisconsin at Madison, joined with more than a dozen other colleagues in writing the letter. The letter calls for five types of proposed studies with H7N9 to provide information that can assist surveillance activities, Science reports.

Fouchier and Kawaoka are known for authoring studies that were involved in a recent H5N1 virus gain-of-function controversy in the scientific community.

The authors proposed to perform experiments on viral immunogenicity, to test genetic changes on virulence, host range or transmissibility, adaptation, to evaluate the potential of H7N9 viruses to become better adapted to mammals, drug resistance, to assess the possibility that drug resistance could emerge in circulating viruses, transmission, to assess the pandemic potential of circulating strains, and pathogenicity, to identify mechanisms that would allow H7N9 viruses to become more pathogenic.

"The risk of a pandemic caused by an avian influenza virus exists in nature," the authors said, according to Science. "As members of the influenza research community, we believe that the avian A(H7N9) virus outbreak requires focused fundamental and applied research conducted by responsible investigators with appropriate facilities and risk-mitigation plans in place. To answer key questions important to public health, research that may result in GOF is necessary and should be done."

The hemagglutinin protein of H7N9 viruses contains several motifs characteristic of mammalian-adapted and human influenza viruses. The pandemic risk would increase exponentially if the viruses are able to transmit readily among humans, Science reports.