Moderna starts clinical trial of booster shot targeting omicron Covid variant
Moderna started a clinical trial to study the safety and effectiveness of a booster shot that specifically targets the omicron Covid variant, the company announced Wednesday.
The first participant in the phase two trial has already received a dose of the omicron-specific booster shot, according to the company.
Moderna expects to enroll about 600 adult participants ages 18 and over split equally between two groups. Participants in the first group will have previously received two-doses of Moderna’s original vaccine, and participants in the second group will have previously received the two-dose vaccine and the currently authorized booster shot.
Participants in both groups will receive a single dose of the omicron specific booster.
Moderna also published data on how its 50 microgram booster shot is holding up against omicron. Six months after the third shot, the antibodies that block omicron infection declined, but they still remained detectable in all participants. The data indicates that while the booster weakens over time, it still provides protection against the variant.
The neutralizing antibodies triggered by Moderna’s existing booster declined faster when pitted against omicron, 6.3 fold, compared with a decline of about 2.3 fold against the original strain of the virus over the same time period.
CEO Stephane Bancel said Moderna is reassured the neutralizing antibodies against omicron remain detectable after half a year.
“Nonetheless, given the long-term threat demonstrated by Omicron’s immune escape, we are advancing our Omicron-specific variant vaccine booster candidate,” Bancel said.
Bancel previously said people who received their boosters last fall will likely have enough protection to see them through this winter. However, he cautioned that people might need fourth shots in the fall of 2022 because the strength of boosters will likely decline, as was the case with the original two-doses of the vaccine.
JAN 27 2022
