- A dual-acting vaccine directed against two coronavirus strains reduced the number of symptomatic COVID-19 cases associated with the omicron variant compared to a placebo in a large clinical trial, its developers, Sanofi and GSK, said Friday. The companies said it was the first trial that specifically tested effectiveness “in an environment of high omicron variant circulation.”
- In a test of 13,000 adults, the shot was 65% protective against all symptomatic infections and 72% effective against disease definitively determined to be caused by omicron, Sanofi and GSK said. The data are being submitted to regulators.
- Sanofi and GSK’s vaccine is directed against two older strains of the virus, D614 and beta, which circulated more frequently when the study started more than a year ago. But the findings indicate the shot may still play a potential role as a booster, alongside other omicron-specific shots from Moderna and Pfizer that are currently in development.
The Sanofi-GSK shot combines a synthetic version of the coronavirus’ signature “spike” protein with a chemical designed to enhance an immune response. The vaccine is based on an older technology than the messenger RNA approach underlying Moderna and Pfizer’s products, as well as the viral vectors used by Johnson & Johnson and AstraZeneca. Though the shot still isn’t authorized for use, public health officials believe it and other protein-based shots like it may eventually play a useful role as an alternative option for people who are reluctant to be vaccinated with newer technologies.
Expert advisers to the Food and Drug Administration are scheduled to meet next week to discuss “whether and how” vaccines should be modified as the COVID-19 vaccine pandemic evolves.
Sanofi and GSK only enrolled participants who hadn’t been vaccinated, but they did include study volunteers who had previously been infected. Broadly, the vaccine reduced the incidence of cases in previously infected by 75% compared to placebo, and in omicron-positive, volunteers cases were reduced by 93%.
The companies didn’t release any detailed safety data from the trial other than to state that the vaccine “demonstrated a favorable safety and tolerability profile.”
Earlier this month, Sanofi and GSK announced that a booster based on beta increased immune response to multiple variants of the coronavirus that cause COVID-19, including omicron. The beta-based booster doubled the immune response observed with a booster directed against D614.
In a statement, Thomas Triomphe, Sanofi’s vaccines executive vice president, said the data support the companies’ bid to gain authorization of a beta-based booster. “With the immunogenicity data from our beta-booster vaccine, they support our belief that, in a largely seropositive world, a next-generation beta booster vaccine could provide protection against variants like omicron,” he said.
Sanofi and GSK may not be the first to win FDA authorization of a protein-based COVID-19 vaccine, however. An FDA advisory committee has already recommended clearance of a similar, rival shot from Novavax.