Researchers have developed a nasal spray vaccine for H5N1 avian influenza, utilizing a platform initially created during the COVID-19 pandemic.

Current vaccines primarily prevent severe disease but fall short in reducing viral transmission due to their intramuscular administration, which produces strong antibodies but inadequate mucosal immunity.

The new nasal spray vaccine can be administered as a single dose, providing mucosal immunity at the virus entry point, which is essential for controlling outbreaks.

Animal studies have confirmed the nasal spray's safety and its capability to generate comprehensive immunity, including neutralizing antibodies and T-cell responses.

In March 2024, genetic surveillance revealed mutations in H5N1 that enhance its ability to infect humans, raising concerns about potential human transmission and pandemic scenarios.

H5N1 was first detected in humans in Hong Kong in 1997, and its capacity to mutate and spread poses a significant pandemic risk, particularly following a rise in cases in US dairy farms starting in early 2024.

If clinical trials are successful, this nasal spray vaccine could serve as a critical reserve for future H5N1 outbreaks, significantly shortening development timelines.

In preparation for a potential bird flu pandemic, the US government has allocated over $500 million for the development of mRNA vaccines.

The study detailing the vaccine's development has been published in Nature Communications.