Although the highly pathogenic H5N1 avian influenza A virus (HPAI H5N1) poses a low danger to the general public, public health officials continue to pay close attention to it. According to experts at the National Institutes of Health (NIH), present and in-development vaccinations and therapies provide adequate protection against serious disease. However, Dr. Jeanne Marrazzo, Director of the National Institute of Allergy and Infectious Diseases (NIAID), and Dr. Michael G. Ison, Chief of the Respiratory Diseases Branch at NIAID, wrote in a recent commentary in the New England Journal of Medicine that the need for continuous virus monitoring and evaluation remains paramount. 

"The public should strike a balance between enhanced vigilance and 'business as usual' with respect to HPAI H5N1," said the panel of specialists. Their evaluation comes as the virus has spread globally and recently emerged in unexpected hosts.

Since its discovery in 1996, HPAI H5N1 has spread throughout at least 23 countries, causing epidemics in wild birds and poultry. The virus travelled from Europe to North America in late 2021 and then to South America in 2022, wreaking havoc on birds and marine mammals. Notably, in March 2024, U.S. Department of Agriculture (USDA) scientists discovered HPAI H5N1 in dairy cows, expanding its spread to herds in 16 states. 

Three states have reported finding the virus in dairy cattle over the last 30 days. In 2024, the United States reported 66 confirmed and seven probable human cases, with one more reported in Canada. Infections have resulted from two separate virus subtypes: D1.1 (circulating in birds) and B3.13 (found in dairy cows). 

Drs. Marrazzo and Ison's four pillars provide an interrelated framework that is important for dealing with the continuing HPAI H5N1 outbreak. Collaboration between human and animal health professionals means that knowledge and resources are used to effectively detect and manage cases. Working together is very important for monitoring systems to work well. These systems use sharing data and sequencing genomes to find changes in viruses and track their transmission paths. Such surveillance immediately informs the creation of medical countermeasures, allowing researchers to build vaccinations and therapies that are specific to the virus's developing properties. Finally, preventive measures are the first line of defence, protecting vulnerable groups and limiting exposure to the virus. Together, these techniques form a comprehensive response that strikes a balance between readiness and aggressive action, protecting both public and occupational health. 

The opinion emphasises the need to address unanswered concerns about the virus's propagation, evolution, and overall impact. "Following these steps will enable scientists and public health officials to better understand and mitigate the risks posed by HPAI H5N1," the study's authors write. 

While the immediate risk is modest, focusing on preventative actions provides readiness for any potential increase. Public health officials, academics, and occupational workers must work together to solve the problems posed by this emerging virus.