Flu experts call for new vaccines, drugs and diagnostics
Though no new ground was broken at Thursday’s congressional hearing about national influenza preparedness and response, several less-familiar points were underlined by officials testifying on behalf of the US Department of Health and Human Services.
Influenza, or flu, is a contagious respiratory illness caused by viruses. By all accounts, the US 2017-18 flu season ranks among the most severe in recent decades, with high rates of flu-like illness hitting all regions at once.
Rick Bright, director of the Biomedical Advanced Research and Development Authority, told the House Committee on Energy and Commerce that his group has supported the production of 23 influenza vaccines, antiviral drugs and diagnostics.
The authority, known as BARDA, is tasked with shepherding vaccines, drugs and diagnostics through late-stage development, known as the “valley of death” due to high rates of failure caused by limited commercial market incentives.
However, Bright also said, “we have not had a new class of antivirals for 20 years.” This is a problem because the influenza virus continues to change and so can develop high levels of resistance against the single US Food and Drug Administration-approved antiviral, oseltamivir phosphate, commonly known as Tamiflu.
The US sees 140,000 to 710,000 flu-related hospitalizations and 12,000 to 56,000 flu-related deaths each year, according to Dr. Anthony Fauci, director of National Institute of Allergy and Infectious Diseases.
Looking to the future
The 2017-18 season vaccine has an 36% overall effectiveness rate in preventing influenza, Fauci noted at the hearing, explaining that the egg-based manufacturing process is part of the problem.
“Egg-based technology is time-honored indeed. It has been effective, but it is antiquated. We need to graduate into the 21st century,” he said. Although cell-based technologies are better, recombinant DNA technology is “the way of the future.”
“It is always better to get vaccinated than to not get vaccinated,” Fauci said, underscoring comments from Dr. Anne Schuchat, acting director of the Centers for Disease Control and Prevention.
“Influenza is a formidable adversary,” Schuchat said Thursday, warning that the season is not done. Acknowledging the vaccine’s less-than-optimal effectiveness, Schuchat reminded the committee that “vaccinating children can be lifesaving against the flu,” as the vaccine showed 59% effectiveness in the youngest age group.
“We do know that the vaccines are providing protection to many, and they’re mitigating the severity of the disease,” she said. “We have more data than ever before,” though there is more to learn about the flu.
Dr. Scott Gottlieb, commissioner of the FDA, also addressed the lackluster flu vaccine and said that any explanation is likely to be “complex,” since data suggest that the 2017-18 vaccine “reasonably matched” circulating strains.
When asked about an experimental Japanese antiviral flu treatment touted this year, Gottlieb noted that the Osaka-based drug company, Shionogi & Co. Ltd., has said publicly that it will submit an application to the FDA this year.
Bright noted that this experimental drug, baloxavir marboxil, brings down viral load very rapidly and uses a new mechanism of action, so if the virus becomes resistant to the existing class of antiviral drugs, the new drug would continue to be effective.
BARDA has partnered with the drug’s American-based sponsor, Bright said, for one of about a “dozen or half-dozen” efforts to create a new antiviral.
Gottlieb said that some of the challenges in developing a new flu drug have been commercial ones, specifically getting a return on a new product once it enters the marketplace.
“We are very interested in having a spectrum of antivirals,” Gottlieb said, as they would serve as “backup or alternative approaches” to Tamiflu.
He reminded the committee that the FDA had been criticized by outside groups when it approved Tamiflu because the antiviral showed limited effectiveness yet prominent side effects, such as vomiting.
Overall, the Health and Human Services officials harmonized their testimonies like a well-rehearsed chorus. Before concluding the hearing, Committee Chairman Gregg Harper of Mississippi joked that he deserved college credit for sitting through Fauci’s colorful slide show used to explain the need for a universal flu vaccine.