Researchers develop broadly protective mRNA Vaccines against COVID-19 Variants

In a study published today in Science Translational Medicine, researchers at The University of Texas Medical Branch and collaborative institutions suggest an mRNA vaccine approach that can provide broad protection against existing and future COVID-19 variants.

Emergence of highly transmissible SARS-CoV-2 variants has posed constant challenges to the current COVID-19 vaccines. But by developing a vaccine that targets two viral proteins rather than one, scientists at UTMB may have found a way to combat the variants.

“Our data showed that dual spike and nucleocapsid mRNA vaccination provided robust control of both Delta and Omicron variants in preclinical models,” said Haitao Hu, PhD, lead author of the study and associate professor of Microbiology and Immunology at UTMB.

In the study, researchers generated nucleoside-modified mRNA vaccines that encode the SARS-CoV-2 spike protein (mRNA-S) or nucleocapsid protein (mRNA-N). They showed that mRNA-N vaccination alone provided modest protection against multiple SARS-CoV-2 strains. When researchers combined mRNA-N with the clinically proven spike mRNA vaccine (mRNA-S), the results showed that combination mRNA vaccination induced robust control of both Delta and Omicron variants in the lungs of vaccinated animals.

In addition, combination mRNA vaccination also provided additional control of Delta and Omicron variants in the upper respiratory tracts of the animals.

“These data are important and indicate that this vaccine approach may also reduce the risk of viral transmission,” said Kenneth Plante, PhD, study co-lead author and assistant professor of Microbiology and Immunology at UTMB.

The mRNA vaccines generated in this study were based on the original or wild-type SARS-CoV-2 viral sequence. Thus, dual mRNA vaccination may represent a robust and broadly protective vaccine platform in face of future viral mutations.

“This research presents a proof-of-concept that a vaccine approach targeting a more conserved viral protein, in addition to the variable spike protein, provides strong and broad protection against SARS-CoV-2 variants in preclinical models,” Hu said. “Given the proven safety profile of mRNA vaccines in large human populations, we hope that this vaccine approach will be further developed and advanced to clinical testing in near future.”

The study was a collaboration involving scientists from the University of Texas Medical Branch, the University of Pennsylvania, and the University of Virginia.