Sanofi-GSK next-generation COVID-19 booster vaccine makes strong protective showing against variants of concern

In two trials of a new Sanofi-GSK COVID-19 booster vaccine, strong immune responses were offered to previously vaccinated adults, and solid protection was offered against variants of concern, according to the company’s latest data.

This booster is modeled on the Beta variant antigen, including GSK’s pandemic adjuvant. In both trials, it showed a favorable safety and tolerability profile among recipients, and the immune response it prompted proved stronger even than Pfizer-BioNTech’s Comirnaty booster, with 76.1 percent of participants showing at least a 10-fold increase in neutralizing antibody titers against the original D614 SARS-CoV-2 strain by day 15 of testing. This is compared to 63.2 percent for recipients of the Comirnaty booster and 55.3 percent for Sanofi-GSK’s first-generation booster candidate.

Respectively, the trials consisted of the VAT02 Cohort 2 and COVIBOOST VAT013 programs. COVIBOOST brought in 247 participants for testing of the three boosters noted above, while Cohort 2 included 1,500 participants. While the trials showed the capabilities of Sanofi-GSK’s latest booster candidate on all fronts, it fared particularly well against Omicron, providing a 40-fold increase in antibody titers against BA.1 in preliminary data, compared to a 15-fold increase against the parent virus and 30-fold increase against Beta.

“COVID-19 keeps evolving, and the combination of emergence of variants and waning immunity is likely to lead to the need for additional booster shots, at least in some populations,” Thomas Triomphe, executive vice president of Sanofi Vaccines, said. “The Beta variant expresses similar mutations across multiple variants of concern, including Omicron, making it a strong vaccine candidate to confer broad protection against multiple strains of COVID-19. Seeing the cross-neutralization data from the independent AP-HP study, we believe this next-generation booster could have an important role to play for public health vaccination campaigns. We look forward to submitting these data to global regulatory authorities.”

Full results of VAT02 are expected to be published in a peer-reviewed journal later this year, while results from the independent COVIBOOST study – run by the Assistance Publique – Hôpitaux de Paris (AP-HP) and funded by the French Ministry of Solidarity and Health and Sanofi – is already available on a preprint server, pending publication.

Sanofi-GSK intends to submit relevant data to regulatory authorities soon and hopes to make the booster available sometime this year.