GSK and the German biopharmaceutical company CureVac said their second-generation mRNA Covid-19 vaccine demonstrated an improved immune response than the first generation, marking higher neutralizing antibody capacity against the variant strains.

GSK and the German biopharmaceutical company CureVac said their second-generation mRNA Covid-19 vaccine showed an improved immune response with a higher antibody neutralizing capacity against the variant strains.
GSK and the German biopharmaceutical company CureVac said their second-generation mRNA Covid-19 vaccine showed an improved immune response with a higher antibody neutralizing capacity against the variant strains.

The preclinical study assessed the Covid-19 immune response and protection of CVnCoV, a first-generation vaccine candidate, and CV2CoV, the second-generation vaccine candidate, in non-human primates. The companies immunized cynomolgus macaques, a non-human primate, 12 micrograms of either their first-generation vaccine candidate or the second-generation vaccine with a 28-day interval.

The group given the CV2CoV had a faster response, higher titers of antibodies, and stronger memory B and T cell activation than those receiving the first-generation candidate. The second-generation vaccine candidate also demonstrated higher neutralizing antibody capacity in all variants, including beta, delta, and lambda strains.

In addition, when given to the primate model, CV2CoV effectively removed the Covid-19 virus from lungs and nasal pathways, showing a higher preventive effect in the study.

“In the animal study, CV2CoV has shown broad antibody and cellular immune responses similar to immune responses observed after being infected by the Covid-19 virus,” CureVac CSO Igor Splawski said. “The study shows that the immune responses and protection generated by the second-generation vaccine candidate, based on our mRNA technology, have shown improved responses against the Covid-19, including beta, delta, and lambda variants, in primates.”

Rino Rappuoli, chief scientist and head of GSK Vaccines R&D unit, said, “The mRNA technology is our key strategy, and we have invested significantly in various mRNA programs with CureVac.”

Rappuoli said that the strong immune response and preventive effects of the second-generation mRNA vaccine confirmed in the preclinical trials are very encouraging and will be an important milestone for future development.

GSK explained the optimized mRNA-based vaccine used in the recent collaboration could be developed as a multivalent or combination vaccine that responds to various strains. The two companies plan to start the phase 1 clinical trial for CV2CoV in the fourth quarter of 2021 after completing the ongoing preclinical trial phase.

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