A new universal flu vaccine protects against influenza B virus, provides broad defense against different strains and improves immune protection, according to a new study by researchers at Georgia State University’s Institute of Biomedical Sciences.
A double-layered protein nanoparticle vaccine consisting of a stable portion of the influenza virus (the hemagglutinin (HA) stalk) induces a broad reactive immune response and provides robust and sustained cross-immunity against two lineages of influenza B strains Conservation. The findings are published in the journal biomaterials.
Influenza epidemics pose a major threat to public health, and influenza B has coincided with several severe influenza outbreaks. About a quarter of clinical infections each year are caused by influenza B virus. Influenza B viruses are sometimes the predominant strains of flu seasons, such as the 2019-20 US flu season, when influenza B viruses caused more than 50% of infections.
Influenza B has two genetically distinct lineages and triggers different immune responses. Seasonal influenza vaccines are developed using one or both lineages of influenza B viruses, but they are limited by the ability of circulating strains to evade the immune system or vaccination. These vaccines are often ineffective because the variable part of the influenza virus (the HA head) evolves. Therefore, seasonal influenza vaccines need to be reformulated and updated frequently. To overcome these limitations, there is an urgent need for a universal influenza vaccine that contains conserved parts of the virus and provides broad cross-protection against different virus strains.
“In this study, we generated structurally stable HA stalk antigens from influenza B virus and fabricated bilayer protein nanoparticles as universal influenza B vaccine candidates,” said the study’s senior author, the institute Dr. Baozhong Wang, Distinguished University Professor. Biomedical Sciences at Georgia State University. “We found that layered protein nanoparticles bound to structurally stable constant antigens have potential as a universal influenza vaccine with higher efficacy and breadth of immune protection.”
Nanoparticle vaccines were tested in cell cultures and mice. Cell culture studies have found that protein nanoparticles are efficiently taken up to activate dendritic cells, which are essential for inducing 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 we have previously studied with the influenza B nanoparticles we made and tested here to create a multivalent universal influenza nanoparticle that targets both influenza A and B Vaccines,” Wang said.
Co-authors of the study include Yufeng Song (first author), Wandi Zhu, Ye Wang, Lei Deng, Ma Yao, Chunhong Dong, Gilbert X. Gonzalez, Joo Kim, Wei Lai, Sang-Moo Kang, and Bao-Zhong Wang Georgia Biomedical Center for Inflammation, Immunity and Infection, Institute of Science. Deng is also affiliated with Hunan University in Changsha, China.
The research was funded by the National Institute of Allergy and Infectious Diseases (NIAID) of the National Institutes of Health (NIH).