Since the beginning of Donald Trump’s administration in January, key US public health organizations have reduced their pandemic preparedness efforts regarding potential avian flu outbreaks. However, in contrast, another government agency has ramped up its activities.

The U.S. Department of Health and Human Services (HHS) previously conducted regular updates on measures to prevent a broader transmission of the deadly avian influenza virus known as H5N1 among humans, but these efforts were largely suspended after Trump took office. Funding for vaccines targeting the virus was also cancelled. Meanwhile, the USDA intensified its fight against the spread of H5N1 in poultry and dairy populations.

This particular strain of avian flu, named H5N1, poses a significant risk to human health, with about half of the nearly 1,000 individuals who tested positive globally since 2003. While the virus spreads quickly among birds, it remains poorly adapted to infect humans and is not known to transmit between individuals. However, mutations might enhance its ability to spread among mammals, presenting an escalating risk with increasing infections in mammals.

The likelihood of H5N1 evolving into a more human-threatening variant has significantly amplified since March 2024, when it transitioned from migratory birds in Texas to dairy cattle. More than 1,070 flocks across 17 states have since been affected.

H5N1 also impacts poultry, making it more human-compatible. Since 2022, nearly 175 million domestic birds in the US have been culled due to H5N1, with 71 people testing positive after direct contact with infected livestock.

“We must take [H5N1] seriously. Its spread continues, and it frequently spills over into humans,” says Sheema Calkdawara from Emory University in Georgia. The virus has already claimed lives in the US, including children in Mexico this year.

However, the number of incidents has minimized since Trump took office, with the last recorded human case in February and a significant reduction in affected poultry herds by 95% from then through June. Outbreaks within dairy cattle herds are also being managed effectively.

The cause of this decline remains unclear. Some speculate it may be due to a decrease in bird migration, limiting the opportunities for the virus to jump from wild birds to livestock. It may also reflect the USDA’s proactive containment strategies on farms. In February, USDA detailed a $1 billion investment plan to combat H5N1, which includes free biosecurity evaluations to help farmers enhance their defenses against the virus. Only one workplace among the 150 reviewed reported an outbreak.

Under Trump’s administration, the USDA also maintained its national milk testing initiative, requiring farms to submit raw milk samples for influenza testing. Should a farm test positive for H5N1, the USDA can monitor livestock and take preventative measures. The USDA initiated a comprehensive program in December, further enhancing their engagement in 45 states.

“The National Milk Test Strategy is a robust approach,” states Erin Sorrell from Johns Hopkins University in Maryland. Coupled with improvements in on-farm biosecurity, milk testing is crucial for containing outbreaks, Sorrell believes.

Despite the USDA’s heightened efforts concerning H5N1, HHS doesn’t seem to be keeping pace. According to Sorrell, the decrease in human cases may also be due to diminished surveillance resulting from staff cuts. In April, HHS announced 10,000 job cuts, impacting 90% of the workforce at the National Institute for Occupational Safety and Health, which monitors H5N1 incidence among farm workers.

“As the saying goes, you can’t detect something unless you test for it,” Sorrell comments. Nevertheless, a spokesperson from the US Centers for Disease Control and Prevention (CDC) stated that their guidance and surveillance initiatives remain unchanged. “State and local health departments are still tracking illnesses in individuals exposed to sick animals,” they expressed to New Scientist. “The CDC is dedicated to promptly sharing information regarding H5N1 as necessary.”

Vaccination strategies are another area of contention between USDA and HHS. USDA has allocated $100 million towards the development of vaccines and additional strategies to mitigate H5N1’s spread among livestock, while HHS has halted $776 million in contracts aimed at developing influenza vaccines. This contract, which ended on May 28, was with Moderna for a vaccine targeting various influenza subtypes, including H5N1, potentially leading to future pandemics. This announcement coincided with Moderna revealing that nearly 98% of around 300 participants who received two H5 vaccines in clinical trials exhibited antibody levels considered protective against the virus.

The US currently possesses approximately 5 million doses of the H5N1 vaccine, produced via egg-based and cultured cell methods, which is more time-consuming compared to mRNA vaccines such as Moderna’s. Sorrell observes that Moderna’s mRNA vaccine platform enables rapid government response and production capabilities during a pandemic, providing a solid foundation should a general public vaccine be required.

HHS’s cancellation of its contract stemmed from concerns regarding the mRNA vaccine technology, an issue previously flagged by Robert F. Kennedy Jr., a leading public health figure in the nation. “The reality is that mRNA technology remains inadequately tested, and we will not waste taxpayer dollars repeating past errors,” stated HHS Communications Director Andrew Nixon, as reported by New Scientist.

However, mRNA technology is far from novel and has been in development for over 50 years, with various clinical trials confirming its safety. Like all treatments, there can be mild side effects, but these are typical of most medical interventions. In a recent announcement, Moderna indicated its intention to seek alternative funding avenues for the project.

“I firmly believe we shouldn’t dismiss any option, including various vaccine strategies,” asserts Calkdawara.

“Vaccinations are the most effective defense against infectious diseases,” emphasizes Sorrell. “Having them available as a contingency provides a wider range of options.”