May 18, 2021 -- Clover Biopharmaceuticals said that its second-generation, protein-based COVID-19 vaccine candidate has demonstrated in preclinical testing that it can provide broad neutralization of the original SARS-CoV-2 strain as well as variants of concern.
Mice that were vaccinated with two doses of the modified B.1.351 Spike (S)-Trimer at day 0 and day 21 showed strong humoral immune responses that broadly neutralize the original SARS-CoV-2 variants first identified in South Africa (B.1.351), Brazil (P.1), and the U.K. (B.1.1.7), according to Clover.
In other results, the researchers reported that immunization with two doses of Clover's SCB-2019 first-generation vaccine candidate and a third booster dose on day 35 of either SCB-2019 or B.1.351 S-Trimer increased cross-reactive neutralizing antibodies against B.1.351. These findings demonstrate the potential importance of booster doses, according to Clover.
The research is available as a preprint on bioRxiv and also will be submitted for a peer-review publication, the company said. Clover said it intends to continue evaluation of B.1.351 S-Trimer and advance a second-generation COVID-19 vaccine candidate into clinical trials in the second half of 2021.