Next generation mRNA vaccines

In 2020, I was a subject in the Moderna phase III trial for their COVID mRNA vaccine. At the same time, Pfizer-BioNTec trialed a similar mRNA vaccine. Both mRNA vaccines proved highly successful. In both cases, chemically modified mRNA encoding the SARS-CoV-2 spike protein is injected, programming cells that receive the mRNA to produce and secrete spike protein until the mRNA decays.

Now, a innovative self-amplifying mRNA vaccine has been approved in Japan has been developed that requires far less modified mRNA:

“Self-amplifying mRNA vaccines contain a gene that encodes the spike protein as well as viral genes that code for replicase, the enzyme that serves as a photocopier. So one self-amplifying mRNA molecule can produce many more.”

This self-amplifying mRNA proved to be more effective than the Pfizer-BioNTec vaccine in eliciting a high-titer antibody response.

One concern I have is that the expression of the viral replicase will elicit a T-cell-mediated immune response that will block booster injections by killing cells that express the replicase proteins.

Stephanie Arnett/Mittr | ENVATO

self-amplifying mRNA vaccines for COVID