FDA Chief on H5N1: 'We Have to Be Ready'

FDA Commissioner Robert Califf, MD, described his agency's role in helping to prevent a wider outbreak of H5N1 avian influenza during a hearing of the Senate Appropriations Committee on Wednesday.

While the risk to the public is still low, upfront investments and pandemic preparedness are critical, he said. "If we institute the countermeasures now, and reduce the spread of the virus ... we're much less likely to see a mutation that jumps to humans for which we're ill-prepared."

Upon first learning about the outbreak, the FDA developed a program to test milk to ensure it was safe to drink, recognizing the strong likelihood that more dairy cattle herds had been infected than had been initially identified, Califf said.

After testing raw, unpasteurized milk from bulk tanks, the FDA found that about 20% of a national sample contained virus fragments, he explained, noting that the agency went on to test pasteurized milk and ultimately found "no evidence of live virus."

While the supply of dairy products is safe, Califf said, "this virus, like all viruses, is mutating ... So we've got to have testing, got to have antivirals, and we need to have a vaccine ready to go ... if the virus does mutate in a way that jumps into humans on a larger level."

Committee ranking member Sen. John Hoeven (R-N.D.) pointed out that there has already been one case in a human -- a dairy farm worker in Texas.

Of note, conjunctivitis was the only symptom reported by the dairy farm worker.

"The real worry is that [the virus] will jump to the human lungs, where when that has happened in other parts of the world for brief outbreaks, the mortality rates have been 25%," Califf said, noting that that would be 10 times worse than COVID.

Whether a mutation could occur that would make the receptors in the lining of human lungs susceptible to the virus is "a mathematical probabilistic thing," he added, but transmission through the airways "would be really bad."

"So, we have to be ready," he said. "And we have to do everything we can to limit the spread of the virus, which has gone around the world multiple times now in many different species."

The FDA is among a handful of government players responsible for responding to the H5N1 outbreak.

The Department of Agriculture regulates cows, the FDA regulates milk, and the CDC is responsible for the health of dairy farm workers, Califf said. At the highest level, the White House Office of Pandemic Preparedness and Response Policy, which launched in 2023, coordinates across all of the relevant agencies. The leaders of these agencies have a daily call to review what happened the previous day, and to discuss their short- and long-term plans. Within HHS, there's a separate call that includes the FDA, CDC, and the Administration for Strategic Preparedness and Response.

Hoeven asked Califf how the FDA can implement "a barrier" to prevent the spread from animals or byproducts to humans.

"There is no absolute barrier that can be created, but there are elements of protection that are important," Califf said. For example, he noted that the mortality rate from the virus in cows is about 1%, which means a sick cow can potentially spread it to a dairy farm worker.

So, just like with hospital workers who wore personal protective equipment (PPE) during the pandemic, dairy farm workers who are near infected animals will also need to wear PPE, he continued, which is something that's already become routine among poultry workers.

During the hearing, Califf also presented the agency's 2025 budget request of $7.2 billion, which is a $341 million increase over fiscal year 2024 enacted levels.

The budget includes $12.3 million to improve the supply chain across all areas of products, $8.3 million to strengthen and expand data modernization capabilities, and $2 million to carry out common business processes and data optimization.

Califf also described the "largest reorganization" in the history of the agency, with particular attention to food safety (in light of recent incidents like the infant formula crisis).

The agency plans to gather all resources and personnel from across different branches under one new Human Foods Program and under the direction of a single leader, a new deputy commissioner. In total, the agency is requesting an additional $15 million for the reorganization.

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