CureVac, GSK's Experimental COVID Variant Vaccine Effective in Mice: Study

By Ludwig Burger

April 22, 2022

FRANKFURT (Reuters) - CureVac and GSK's second-generation vaccine candidate targeting two recent COVID-19 variants has been shown to be highly effective in preclinical studies on mice, CureVac said, as it seeks to catch up with rivals' development work.

A study in mice, published as a preprint on the bioRxiv website, showed that the bivalent vaccine candidate, designed to address the Beta and Delta variants of the coronavirus, elicited total neutralizing antibody levels that were comparable to the monovalent vaccine candidates targeting only one of the variants.

"During exposure of the vaccinated animals to either the Beta or the Delta variant, the bivalent mRNA vaccine significantly reduced the viral load in the animals," CureVac said in a statement on Thursday.

While the early results point to potentially broader protection in never-immunized subjects from one bivalent shot compared to a vaccine that only addresses one variant, validation via much more onerous testing on humans will be required.

Germany's CureVac has specialised in mRNA, the same technology used by the BioNTech-Pfizer partnership as well as by Moderna for their established COVID shots.

After failed efforts to bring a COVID-19 vaccine to market last year, CureVac intensified its work with partner GlaxoSmithKline on improved vaccine versions.

Germany, which backed the biotech firm's initial development attempt, in a renewed show of confidence this month signed a contract with CureVac and GSK for over 80 million doses of future mRNA vaccines to bolster supplies in case of further public health emergencies.

BioNTech-Pfizer and Moderna are ahead in the testing on humans of experimental monovalent and bivalent vaccines to better protect against the dominant Omicron variant and also against any future variants.

CureVac at the end of March started early testing on humans of an improved monovalent shot, designed to target the original COVID-19 coronavirus that was discovered in Wuhan, China.