H5 flu vaccines: what should be done to reduce the risk of a pandemic?

“At this critical juncture, decisions about vaccine development, storage, and deployment will shape our ability to respond to immediate and future pandemic risks,” write Jesse Goodman, MD, PhD; Rick A. Bright, PhD; and Nicole Lurie, MD, MSPH, in an article JAMA Viewpoint published on September 4.

The current H5N1 influenza outbreak in North America has infected poultry, cows, wild birds, marine and terrestrial mammals, and at least 13 humans, primarily on dairy and poultry farms. No human-to-human transmission has been reported.

“It is very concerning that this H5N1 strain, compared to previous ones, has seen unprecedented spread among mammals,” Goodman said. “Although human cases have been relatively mild to date, the threat of a pandemic is real, given the virus’s widespread and continued presence in close proximity to humans and its ability to reassort with human influenza viruses or mutate to acquire the ability to transmit between humans.”

Goodman is a professor of medicine at Georgetown University School of Medicine and a former chief scientist at the FDA; Bright is director of Bright Global Health and a former deputy assistant secretary for preparedness and response and director of the Biomedical Advanced Research and Development Authority (BARDA); and Lurie is executive director of preparedness and response at the Coalition for Epidemic Preparedness Innovations and director of CEPI-US and a former assistant secretary for preparedness and response at the U.S. Department of Health and Human Services.

Focusing on vaccines, Goodman and colleagues outline short-, medium-, and long-term actions to combat H5N1 risk: protecting exposed people and reducing pandemic risk; renewing vaccine supplies and building capacity; and laying the foundation for mitigating future threats.

In the short term

The authors note that the U.S. government has 4.8 million doses of H5N8 vaccine in stockpile, which should provide cross-protection against current H5N1 strains.

In the short term, the authors say, “subject to adequate supporting data and regulatory review, stockpiled vaccines should be offered voluntarily to those at risk.” Those at risk include farm workers in close contact with animals.

Medium term

In the medium term, the authors stress the importance of ensuring that vaccine stocks are replenished with doses that are well-matched to circulating viruses. The goal is to ensure that at least 20 million people, especially essential workers, can be rapidly vaccinated in the event of a pandemic.

In addition, the public health trio calls for action now to prepare and improve capacity for pandemic influenza vaccine development and production globally, including by evaluating the potential of mRNA vaccines, which offer faster and more scalable manufacturing processes.

In the long term

Longer term, Goodman and colleagues advocate exploring pre-pandemic vaccination strategies. This could involve vaccinating high-risk groups during interpandemic periods to boost population immunity against potential pandemic strains, a strategy that, while unproven, could significantly mitigate the impact of future pandemics.

Finally, the authors call on elected officials, governments, international partners, and the private sector to address the threats of H5N1 and other pandemic influenza with a comprehensive human and animal health strategy that includes pandemic vaccines, diagnostics, therapeutics, and nonpharmaceutical interventions. They emphasize that the convergence of health and agricultural concerns, including the protection of workers, livestock, and the economy, offers an opportunity to transcend divides.

They conclude: “The time to act decisively is not when a pandemic strikes, but today, while we have the chance.”