US implements pre-emptive measures amid rising H5N1 cases

New Delhi: The US is ramping up its pandemic preparedness measures in response to rising cases of avian influenza A (H5N1) among cattle, as reported by GlobalData.

Despite the lack of evidence suggesting human-to-human transmission, government health officials are taking proactive steps, including the development and stockpiling of two vaccine candidates.

Avian influenza A (H5N1) primarily affects wild birds and poultry. Since March 2024, a multi-state outbreak has spread among dairy cattle, impacting 49 herds across nine states. Notably, there has been one human case reported among a dairy worker and evidence of transmission from infected cattle to cats at a dairy farm.

Stephanie Kurdach, Infectious Disease Analyst at GlobalData, comments: “Although H5N1 infections in humans are rare, they can cause severe disease and should be taken seriously. According to the World Health Organization (WHO), the mortality rate among humans infected with influenza A (H5N1) is approximately 50%.”

In preparation for a potential human outbreak, the US government has stockpiled two vaccine candidates. If necessary, hundreds of thousands of doses could be distributed within weeks, and over 100 million doses within three to four months.

Kurdach added, “These precautionary measures being taken by the US government are essential in order to prepare for and mitigate the effects of a potential pandemic, which is a possibility if viral mutations allow H5N1 to be readily transmitted between humans.”

According to the WHO, the next pandemic is most likely to be caused by the influenza virus. GlobalData has identified 13 vaccines currently in clinical development (Phases I-III) for pandemic influenza/influenza A(H5N1). Noteworthy candidates include GSK’s influenza A/H5N1 vaccine and Moderna’s mRNA-1018, both of which are mRNA vaccines in Phase I/II trials. mRNA vaccines are particularly advantageous in a pandemic scenario due to their rapid production capabilities compared to traditional vaccines.

Kurdach concludes, “Although the current risk of infection with influenza A(H5N1) to the general public is low, it is important to avoid contact with domestic and wild birds, and to cook poultry products well.”

The Centers for Disease Control and Prevention (CDC) are closely monitoring H5N1 outbreaks and potential human exposures in collaboration with the US Department of Interior, the US Department of Agriculture, and state and local health departments. Surveillance efforts include public health laboratories, emergency departments, clinical laboratory trends, and wastewater sources.