- A booster shot of Moderna's authorized coronavirus vaccine significantly increases antibody levels against the omicron variant, according to the results of laboratory tests the company disclosed Monday. The update comes days after another analysis indicated the initial two-shot regimen is less effective at neutralizing omicron than other variants like delta.
- As a result of the booster's apparent cross-protection against multiple variants, Moderna said it will focus its efforts away from a more complex "multivalent" shot and toward further study of its existing booster dose formulation. The biotech said it will still develop an omicron-specific booster, however, and aims to begin clinical testing of that in early 2022.
- Moderna's findings are similar to those of Pfizer and BioNTech, which reported that low antibody levels against omicron from their vaccine's initial two-shot regimen could be raised substantially by an additional dose. The booster shot of Pfizer's and BioNTech's vaccine increased antibody levels against omicron by 25-fold, while Moderna observed a 37-fold increase between pre- and post-boost levels.
Since omicron's detection less than a month ago, scientists and public health authorities have scrambled to determine whether the current arsenal of treatments and vaccines will be sufficient to fight it. The news so far has been mixed — the variant appears to be more transmissible and seems to dodge antibody drugs and vaccines more readily, but may not completely escape the protection they offer.
Moderna is the latest to detail the effects omicron has on its vaccine. The company tested the blood of boosted individuals against an engineered version of omicron called a "pseudovirus." The samples were from groups of 20 people given various versions of Moderna's boosters, including the authorized 50 microgram dose, the 100 microgram dose of the initial vaccination regimen, which is also the authorized third dose given to immunocompromised people. Also included in the analysis were three groups of people given experimental multivalent booster candidates.
Among the 100-microgram dose group, omicron-specific antibody levels climbed 83-fold over pre-boost levels, Moderna said. Multivalent boosters also increased omicron-specific antibodies by a similar amount to the 50 and 100 microgram shots of the authorized vaccine, the company said.
The data was released via a Moderna press release and has not been peer reviewed.
Moderna CEO Stéphane Bancel described the data as "reassuring," but added that omicron's rapid spread highlights the challenges vaccine makers face as they try to respond. Earlier versions of variant-specific vaccines, which address the original strain as well as beta and delta, may become obsolete after an omicron wave, and an omicron-specific booster due to begin human testing next year might not gain authorization before a new dominant strain emerges.
The authorized vaccine used as a booster, meanwhile, still stimulates an immune response to omicron and could remain effective for some time.
Shares in Moderna initially rose in Monday morning trading, before falling to trade back by nearly 4%.