In a small group of monkeys, an omicron-specific version of Moderna’s COVID-19 vaccine did not protect against the omicron variant better than Moderna’s current, highly effective booster. This finding casts doubt on whether a switch to variant-specific doses is necessary.
The study was led by researchers at the National Institutes of Health and posted on a preprint server last Friday. The study has not been peer-reviewed or published in a scientific journal. It also has all the limitations of an animal study and only involved eight monkeys. The study’s findings will have to be verified in human trials, which are currently underway.
Still, there’s good reason to think the finding will hold up. As the authors of the study note, this isn’t Moderna’s first variant-specific booster. The company had previously developed a booster against the concerning variant beta. As with the omicron-specific booster, the beta-booster didn’t outperform the original vaccine at protecting primates from beta. And that finding later held up in human trials.