American biotechnology company Moderna announced on Wednesday promising initial results from trials of its modified COVID-19 vaccine, which specifically targets the Omicron variant and can be administered as a new booster shot in the coming months.
Moderna stated that a 50 microgram booster dose produced a higher antibody response against the Omicron variant one month after administration. The new vaccine, also developed using messenger RNA technology and named mRNA-1273.214, is a bivalent vaccine, meaning it targets both the original strain of the virus—like the vaccines currently being administered worldwide—as well as the Omicron variant.
With this fourth dose, antibodies against Omicron increased eightfold compared to pre-injection levels, while the increase was fourfold using the original vaccine, according to the company.
Stefan Bancel, CEO of Moderna, stated, "We expect extended protection against concerning variants with the mRNA-1273.214 vaccine, making it our primary candidate for booster doses in the fall of 2022." He added, "We are sending our preliminary data and analyses to regulatory authorities and expect the bivalent booster vaccine against Omicron to be available by late summer."
The company also mentioned that they plan to study the immune response again 91 days after vaccination, noting that the side effects of this dose were similar to those experienced with the original vaccine and were well tolerated by the 437 participants in the trial.
While Moderna's announcement is good news and has been welcomed, some experts noted that the available data does not guarantee that the new vaccine will be more effective at preventing infections or even severe cases of the disease. Pfizer-BioNTech is also conducting trials on an updated version of its vaccine specifically targeting Omicron.