A new universal flu vaccine protects against influenza B viruses, offering broad protection against different strains and improved immune protection, according to a new study by researchers at Georgia State University’s Biomedical Sciences Institute.
The bilayer protein nanoparticle vaccine, which was engineered with a stabilized part of the influenza virus (the hemagglutinin (HA) stem), induced broadly reactive immune responses and provided robust and sustained cross-immune protection against influenza B virus strains of both lineages. The findings are published in the journal Biomaterials.
Influenza epidemics are a major threat to public health, and influenza B has coincided with several severe influenza epidemics. Each year, about a quarter of clinical cases of infection are caused by influenza B viruses. Influenza B viruses are sometimes the dominant circulating strains during flu seasons, such as the 2019-20 US flu season, when influenza B caused more than 50 rate of infections.
Influenza B has two lineages that are genetically different and elicit different immune responses. Seasonal influenza vaccines have been developed with one or both lineages of influenza B viruses, but they are limited by the ability of circulating strains to escape the immune system or vaccination. These vaccines are often ineffective because the variable part of the flu virus (the HA head) evolves. As a result, seasonal flu vaccines must be reformulated and updated frequently. To overcome these limitations, a universal influenza vaccine containing conserved parts of the virus and providing significant broad cross-protection against different virus strains is urgently needed.
“In this study, we generated structurally stabilized HA stem antigens from influenza B and produced bilayer protein nanoparticles as universal influenza B vaccine candidates,” said Dr. Baozhong Wang, senior author of the study and distinguished university professor at the Institute of Biomedical Sciences in Georgia State University. “We found that layered protein nanoparticles incorporated with structurally stabilized persistent antigens have potential as a universal influenza vaccine with improved immune protective potency and breadth.”
The nanoparticle vaccine has been tested in cell culture and in mice. Studies in cell cultures have found that protein nanoparticles are efficiently taken up to activate dendritic cells, which are critical for eliciting protective immune responses against pathogens. The vaccine was found to be safe, biocompatible, biodegradable and highly immunogenic in animals.
“Our next goal is to combine the influenza A nanoparticles from our previous study with the influenza B nanoparticles we produced and tested here to create a multivalent universal nanoparticle influenza vaccine against influenza A and B,” Wang said.
Study co-authors include Yufeng Song (first author), Wandi Zhu, Ye Wang, Lei Deng, Yao Ma, Chunhong Dong, Gilbert X. Gonzalez, Joo Kim, Lai Wei, Sang-Moo Kang and Bao-Zhong Wang of the Inflammation Center , Immunity and Infection at the Georgia State Institute of Biomedical Sciences. Deng is also affiliated with Hunan University in Changsha, China.
The study was funded by the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH).
Materials provided by Georgia State University. Note: Content may be edited for style and length.