Global Flu Surveillance Faces Crisis Amid Funding Cuts and US-WHO Rift
A significant reduction in global influenza virus sample submissions has been reported, potentially impacting the effectiveness of future flu vaccines and the understanding of viral evolution. This development coincides with challenges to the World Health Organization's (WHO) funding following the U.S. withdrawal from the organization, despite the U.S. Centers for Disease Control and Prevention (CDC) continuing virtual participation in key international meetings.
The Steep Decline in Sample Submissions
Flu virus samples are critical for informing the understanding of viral evolution and guiding the World Health Organization's annual flu vaccine design. Reports indicate a concerning decrease in these submissions.
From February through July, the CDC received only 427 samples, marking a substantial 60% reduction compared to the same period in the previous year. By July, merely 12 countries had submitted samples to the CDC, representing a significant 65% decrease from 2024 figures. Demetre Daskalakis, former head of the National Center for Immunization and Respiratory Diseases at the U.S. CDC until August, stated that the flow of this crucial data had substantially decreased.
Maria Van Kerkhove, interim director of the WHO's department of epidemic and pandemic threat management, also reported a decrease in sample shipments to the WHO's global network, which includes seven collaborating centers and over 150 National Influenza Centers worldwide. While one report indicates that the flow of samples slowed but has since resumed following a reduction in WHO funding, concerns about the long-term sustainability of the system persist due to ongoing funding limitations.
"A sustained reduction in sample submissions could result in a less complete understanding of influenza evolution and significantly impact surveillance."
Daniel Jernigan, who resigned as director of the CDC's National Center for Emerging and Zoonotic Infectious Diseases in August, commented that a reduction in incoming virus samples directly impacts vaccine composition, potentially leading to decreased vaccine effectiveness. Kanta Subbarao, a flu researcher at Laval University and former head of a collaborating center, further indicated that a sustained reduction in sample submissions could result in a less complete understanding of influenza evolution and significantly impact surveillance.
U.S. Withdrawal from WHO: Financial and Influential Ramifications
On January 20, President Trump announced the U.S. withdrawal from the WHO, citing accusations of Chinese control. This action resulted in an approximate billion-dollar reduction in the WHO's budget, which typically funds the vital shipment of virus samples. Ms. Van Kerkhove stated the WHO is actively seeking alternative funding to maintain its essential flu monitoring and assessment capabilities.
Despite the U.S. withdrawal from the WHO, the CDC participated virtually in a recent week-long meeting organized by the WHO in Istanbul. This meeting involved approximately 50 flu scientists reviewing data on global virus evolution, past vaccine performance, and potential strains for vaccine production for an upcoming flu season. The Department of Health and Human Services (HHS) confirmed CDC's attendance, stating its focus was on providing technical expertise, sharing surveillance data, and contributing to scientific discussions for vaccine strain recommendations. HHS clarified that this participation does not alter the U.S. position on withdrawing from the WHO.
Mr. Jernigan noted that the absence of U.S. officials at the conference table could affect U.S. influence in vaccine strain selection, suggesting that representatives from other countries might be less inclined to prioritize vaccine viruses representing potential circulating strains in the United States without in-person interaction. HHS did not provide a response when asked to address this particular concern.
Vaccine Development and Pandemic Preparedness at Risk
Annually in February and September, scientists from WHO collaborating centers convene to determine the influenza strains for the upcoming northern and southern hemisphere flu seasons. Flu vaccines typically include multiple strains to provide broader protection, as the dominant virus for the next season cannot be precisely predicted.
The selection of vaccine strains relies heavily on predictive analysis informed by specialized laboratories such as the CDC, which conducts viral analysis, sequencing, and ferret testing. Arnold Monto, an epidemiologist at the University of Michigan, stated that reduced sample numbers would complicate these analyses by decreasing available data. WHO officials did not specify the exact reduction in data shared with collaborating centers. The next critical meeting for strain selection is scheduled for February.
"Reduced CDC involvement could diminish U.S. pandemic preparedness."
Mr. Daskalakis expressed concern that the CDC's reduced sample intake might be difficult to reverse, potentially due to countries' reluctance to share data with the U.S. following its WHO withdrawal. He also indicated that reduced CDC involvement could diminish U.S. pandemic preparedness. He noted that the CDC usually receives approximately a dozen candidate vaccine viruses from the WHO network for vaccine production, in addition to thousands of influenza samples. By late August, the CDC had received only two such viruses, which could severely affect the ability to scale up a response to a potential flu pandemic.
Mr. Daskalakis further stated that the CDC's insight into other pathogens, including COVID-19 and polio, is decreasing, which may hinder the agency's ability to identify new viral variants that could lead to outbreaks. He previously observed during the COVID-19 pandemic that delays and reduced coordination had direct impacts on mortality.
The WHO is expected to announce the recommended strains for the upcoming flu season, initiating a nine-month production process for manufacturers.