CureVac and the German Federal Research Institute for Animal Health, Friedrich-Loeffler-Institute (FLI), Germany, reported that mRNA vaccines could induce balanced, long-lived, and protective immunity to influenza A virus infections in various animal models.
In the paper (published in Nature Biotechnology on November 25), the authors described studies showing that an mRNA vaccine encoding full-length influenza A/PuertoRico/8/1934 (PR8HA) hemagglutinin (HA) was immunogenic and induced anti-influenza B- and T-cell responses in mice. They also reported that they targeted additional influenza A virus strains by sequence-matched, HA-specific vaccines, and that all vaccines induced full protection against lethal infections, including H1N1pdm09 swine flu and H5N1 bird flu virus.
The mRNA vaccine was immunogenic and provided long-term protection in newborn as well as in aged mice. Further, the immunized mice were protected through an antibody-dependent mechanism against death and disease upon challenge with the influenza virus. In ferrets and pigs, mRNA vaccines induced immunological correlates of protection, and protective effects similar to those of a licensed influenza vaccine in pigs.
This synthetic vaccine was developed based on CureVac’s RNActive® technology. Each vaccine comprises several different mRNAs encoding for virus-specific antigens, or tumor antigens for cancer treatment. According to the company, modified mRNA, when administered intradermally, becomes incorporated by various cells and translated into protein. Protein fragments are presented as antigens to the immune system, eliciting a balanced T-cell and B-cell immune response as observed in preclinical settings as well as in clinical trials. CureVac is currently evaluating its vaccines in clinical trials for prostate and non-small-cell lung cancers.
Commenting on the potential advantages of mRNA-based vaccines, Ingmar Hoerr, Ph.D., CureVac’s CEO, said, “The synthetic nature of our RNActive vaccines reduces production time dramatically and allows for sequence-matched vaccines that can be produced quickly and reliably in a scalable process. Additionally, our vaccines can be stored at room temperature, thereby avoiding the cold-chain in contrast to all other vaccines on the market and making worldwide distribution of our vaccines logistically and financially attractive.”