Flu: what if a nasal vaccine based on nanoparticles was THE solution?

Made up of nanoparticles, the intranasal vaccine was tested by the researchers on mice. They discovered that it elicits a different immune response against different flu strains. The American study was published in the scientific journal ACS. Applied Materials & Interfaces.

The limits of the annual flu vaccine

Each year, 2 to 8 million people are affected by the flu in France, with excess mortality attributable to the flu of 10,000 to 15,000 deaths, mainly in fragile subjects. Because influenza viruses undergo constant genetic modification, it is necessary to adjust the composition of the vaccine each year to adjust to the most recent strains. But the effectiveness of the vaccine therefore depends on the good match between the composition of the vaccine and the strains in circulation, but also on the age and the immune status of the vaccinated subject.

Seasonal influenza vaccines thus induce narrow immune responses that decline rapidly, making populations vulnerable to new influenza strains.

More than six months of protection

Researchers have developed a vaccine consisting of PEI-HA/CpG nanoparticles. PEI (polyethyleneimine), a robust and versatile delivery system, can simultaneously transport antigens (hemagglutinin, HA) that induce an immune response in the body and adjuvants (CpG) that enhance the body’s immune response to an antigen to optimal immuno-enhancement. The researchers targeted a more stable part of the virus, ideally offering more protection.

This vaccine provided enhanced protection against several influenza strains for more than six months after vaccination. “Nanoparticles show good potential as a cross-protective influenza vaccine candidate“, said Dr. Baozhong Wang, corresponding author of the study and professor at the Georgia State Institute of Biomedical Sciences.

Nasal vaccine, vaccine of the future?

Researchers know: intranasal vaccination is an ideal approach for infectious respiratory diseases such as influenza. It can improve the immune responses at the level of the nasal mucous membranes by preventing influenza infection from the point of entry of the virus.

Long-term effects to watch out for

According to Dr. Chunhong Dong, the study’s first author and postdoctoral fellow at the Institute of Biomedical Sciences, “challenges remain for the research and development of nanoparticle-based vaccines. Although no apparent adverse effects were observed in the study, a more comprehensive evaluation of the safety of the nanoparticle-based adjuvant system is needed before conducting clinical trials in humans.”.

To be continued…