0
0
MEMPHIS, TN – As the H5N1 avian influenza outbreak continues to raise concerns, new research from St. Jude Children’s Research Hospital reveals that current antiviral treatments may be inadequate against the virus found in contaminated cow’s milk.
Scientists have been closely monitoring the H5N1 virus, which has been detected in dairy cows and has infected farm workers, prompting urgent investigations into effective treatments. The study, published in Nature Microbiology, indicates that the two most common FDA-approved flu antivirals, oseltamivir (Tamiflu) and baloxavir (Xofluza), exhibit poor performance against severe H5N1 infections in preclinical models.
“Our evidence suggests that it is likely going to be hard to treat people severely infected with this H5N1 bird flu strain,” said Richard Webby, Ph.D., corresponding author and researcher at St. Jude’s Department of Host-Microbe Interactions. “Instead, reducing infection risk by not drinking raw milk and reducing dairy farm workers’ exposures, for example, may be the most effective interventions.”
The researchers used a mouse model to assess the effectiveness of these antivirals against H5N1 acquired through different exposure routes: the eye, mouth, and nose. These routes represent the most likely ways humans could contract the virus, particularly through contaminated raw milk or exposure to infected animals.
“In general, baloxavir [Xofluza] caused a greater reduction in viral levels than oseltamivir [Tamiflu], but neither were always effective,” explained Jeremy Jones, Ph.D., first author of the study.
Notably, infections acquired through the oral route, simulating the consumption of raw infected milk, resulted in the most severe infections and proved the most difficult to treat. “The virus spread far beyond its normal infection of the lungs,” Webby stated. “It expanded to the brain and the bloodstream, and the antivirals failed to stop it or improve survival outcomes.”
However, baloxavir demonstrated better control of infections acquired through the ocular route, which is particularly relevant for dairy farm workers exposed to splashes or aerosolized particles. “Baloxavir achieved 100% survival compared to 25% with oseltamivir,” Jones noted.
Results for nasal exposure were mixed, with baloxavir showing better viral reduction than oseltamivir, but both antivirals still allowed the virus to reach the brain. While both increased survival rates, neither provided complete protection.
“We showed our existing antivirals’ effectiveness against H5N1 bird flu is route- and drug-dependent, in some cases doing almost nothing,” Webby said. “Therefore, while we explore different drug combinations and doses, we need to do anything we can to reduce the risk of infection, as that is the best way to protect people from this virus right now.”
The researchers emphasize the importance of preventive measures, such as avoiding raw milk consumption and implementing stringent safety protocols for dairy farm workers, to mitigate the risk of H5N1 infection.
Disclaimer: This news article is based on scientific research and should not be interpreted as medical advice. Always consult with a healthcare professional for any health concerns. The findings discussed are based on preclinical models and may not directly translate to human outcomes. Further research and clinical trials are necessary to fully understand the effectiveness of antiviral treatments against H5N1 in humans. The current understanding of H5N1 is rapidly evolving, and information may change.
