With cases of avian influenza A (H5N1) continuing to rise among cattle and humans in the US, scientists and government health officials are preparing for the potential of the virus adapting to enable human-to-human transmission. While there is no evidence yet that H5N1 could spread between humans, pandemic preparedness is essential, and mRNA vaccines offer great potential to mitigate a future pandemic, says GlobalData, a leading data and analytics company.
H5N1 is classified as a highly pathogenic avian influenza (HPAI) virus that predominately affects wild birds and poultry. Since March 2024, there has been an ongoing, multi-state outbreak among dairy cattle, affecting over 900 dairy herds across 16 states, according to the most recent reports from the Centers for Disease Control and Prevention (CDC). Further, there were 66 confirmed cases of H5N1 influenza among humans in the US throughout 2024. The first human H5N1 death was recorded in the US in January 2025.
Stephanie Kurdach, Infectious Disease Analyst at GlobalData, comments: “Although H5N1 infections remain a low risk to the general public, they can cause severe disease and should be taken seriously.”
The CDC is carefully surveilling H5N1 outbreaks and exposures among humans, partnering with the US Department of Interior, the US Department of Agriculture, and state and local health departments. Officials from the National Institute of Allergy and Infectious Diseases (NIAID) remain assured that the current outbreak can be controlled via collaboration, vigilant surveillance, the development of medical countermeasures, and prevention methods. This includes the development of a vaccine candidate, which could be swiftly manufactured and administered in the event of a widespread outbreak among humans.
Kurdach continues: “An mRNA H5N1 vaccine would be particularly beneficial in the event of a pandemic, as they can be manufactured much quicker than traditional vaccines.”
According to GlobalData, there are 12 vaccines in active clinical development (Phases I-III) indicated for pandemic influenza/influenza A (H5N1). Five of these vaccines are being manufactured utilizing mRNA technology, including GSK/CureVac’s influenza A/H5N1 vaccine, Moderna’s mRNA-1018, and Sanofi’s influenza H5 vaccine.
The US Biomedical Advanced Research and Development Authority (BARDA), a department within the Administration for Strategic Preparedness and Response (ASPR), is working to support pandemic influenza preparedness by partnering with developers and manufacturers, supporting the development of vaccines, diagnostics, and therapeutics, and funding ongoing clinical trials. Arcturus Therapeutics’ H5N1 pandemic influenza vaccine candidate, ARCT-2304, is a self-amplifying mRNA vaccine candidate, whose Phase I clinical trial is funded by BARDA.
Kurdach concludes: “There are concerns surrounding the uncertainty of the H5N1 virus; however, the implementation of pandemic preparedness measures, specifically the development of H5N1 mRNA vaccines, offers great potential to mitigate a future pandemic.”