New mRNA Vaccine Platform Offers Broad Protection and Greater Scalability

Researchers from the University of Pittsburgh School of Public Health and Pennsylvania State University have developed a new type of mRNA vaccine that may be more adaptable and scalable for use against rapidly changing viruses such as SARS-CoV-2 and H5N1. Their findings were published in npj Vaccines.

Current mRNA vaccines, including those used for COVID-19, face two main obstacles: they require large amounts of mRNA to be effective, and they must be frequently updated to keep pace with the evolving virus. “The virus changes, moving the goal post, and updating the vaccine takes some time,” explained Suresh Kuchipudi, Ph.D., senior author.

To address these issues, the team designed a proof-of-concept COVID-19 vaccine using a "trans-amplifying" mRNA platform. This method separates the mRNA into two components: the antigen sequence and the replicase sequence. The replicase sequence can be prepared in advance, allowing for faster and larger-scale vaccine production if a new variant emerges.

The researchers also examined the spike protein sequences of all known SARS-CoV-2 variants to identify common features. This enabled them to create a “consensus spike protein” as the vaccine’s antigen, aiming for broader protection.

In mouse studies, the vaccine generated a strong immune response against multiple SARS-CoV-2 strains. According to Kuchipudi, “This has the potential for more lasting immunity that would not require updating, because the vaccine has the potential to provide broad protection.” He also noted that this approach uses an mRNA dose 40 times lower than conventional vaccines, which could significantly reduce production costs.

Kuchipudi added that these findings may help guide the development of efficient vaccines for other evolving RNA viruses, such as those causing bird flu.