Study Finds Universal Influenza B Vaccine Induces Broad and Lasting Protection

A study by researchers at Georgia State University’s Institute of Biomedical Sciences has found a new universal flu vaccine has been found to protect against influenza B viruses that offer broad defenses against different strains and improve immune protection. The double-layered protein nanoparticle vaccine, constructed with a stabilized portion of the influenza virus (the hemagglutinin [HA] stalk), induces broadly reactive immune responses and conferred robust and sustained cross-immune protection against influenza B virus strains of both lineages.

Influenza B has two lineages that are genetically distinct and trigger different immune responses. And, since seasonal flu vaccines are developed with one or both lineages of influenza B viruses, they’re limited by the ability to circulate strains to escape the immune system or vaccination, often making these vaccines ineffective because the variable portion of the influenza virus (the HA head) evolves. As a result, seasonal influenza vaccines need to be reformulated and updated frequently. To overcome these limitations, a universal influenza vaccine containing conserved parts of the virus and providing substantial broad cross-protection against diverse virus strains is needed.

“In this study, we generated structure-stabilized HA stalk antigens from influenza B and fabricated double-layered protein nanoparticles as universal influenza B vaccine candidates,” said Baozhong Wang, PhD, senior author of the study and distinguished university professor in the Institute for Biomedical Sciences at Georgia State University. “We found that layered protein nanoparticles incorporated with structure-stabilized constant antigens have potential as a universal influenza vaccine with improved immune protective potency and breadth.”

The nanoparticle vaccine was tested in cell culture and in mice. Studies in cell culture found the protein nanoparticles were effectively taken up to activate dendritic cells that are critical for inducing protective immune responses against pathogens. The vaccine was found to be safe, biocompatible, biodegradable and highly immunogenic in animals.

“Our next aim is to combine the influenza A nanoparticles from our previous study with the influenza B nanoparticles we have fabricated and tested here to create a multivalent universal influenza nanoparticle vaccine against both influenza A and B,” Dr. Wang said.