A team of researchers from the Institute for Biomedical Sciences at Georgia State University has found that an intranasal influenza (flu) vaccine, which is made of nanoparticles, enhances the body’s immune response to the virus infection and offers broad protection against different strains of the flu virus.

Intranasal flu vaccines are a promising strategy for curbing influenza-related respiratory diseases. In fact, they have been found more effective than vaccines because they can induce mucosal immune responses in the respiratory tract itself, preventing infection at the portal of virus entry, according to Medical Xpress.

In addition to that, intranasal vaccines can stimulate systemic immune responses throughout the body.

The researchers developed an intranasal flu vaccine using a protein called recombinant hemagglutinin (HA) that is found on the surface of flu viruses, as the antigen component of the vaccine. They also developed a nanomaterial and found that it offered immune-enhancing effects on influenza vaccines delivered intranasally.

The study was published in the journal Proceedings of the National Academy of Sciences.

Senior author of the study Dr. Baozhong Wang said, “Conventional flu vaccines predominantly induce antibody responses. However, recent research demonstrates that lung resident memory T cell responses are indispensable for optimal cross-protection against pulmonary influenza infection.”

“The development of lung resident T cell responses requires vaccination by a respiratory route or influenza virus infection,” he added. “Our research opens a new path for the development of needle-free and logistically simplified intranasal flu vaccines for cross-protection.”

Lead author of the study Dr. Chunhong Dong said, “In our study, we reported for the first time that two-dimensional graphene oxide nanomaterials had a potent adjuvant effect in boosting the immune responses of intranasal hemagglutinin (HA) vaccines.”

“This study gives new insights into developing high-performance intranasal vaccine systems with two-dimensional sheet-like nanoparticles,” he added.

“The graphene oxide nanoparticles have extraordinary attributes for drug delivery or vaccine development, such as the ultra-large surface area for high-density antigen loading, and the vaccine showed superior immunoenhancing properties in vitro and in vivo,” Dr. Dong explained. “The nanoplatform could be easily adapted for constructing mucosal vaccines for different respiratory pathogens.”

The study, which was conducted in mice and cell culture, found the intranasal vaccines effective at enhancing immune responses at mucosal surfaces and throughout the body in mice, offering protection against flu virus challenges by the same virus strains and different virus strains. The study findings are also promising because intranasal vaccines are needle-free so they are easy to administer.