The vaccine received CMA from the agency in January 2021 as two 100 µg doses given 28 days apart: with the company now seeking to gain the green light for a 50 μg booster dose.
In the US, Moderna already has FDA authorization for a third dose for immunocompromised individuals, announced last month. On Wednesday last week it submitted data to the FDA for broader authorization (also for a 50 μg booster dose); followed by its submission to the EMA on Friday.
The company expects to submit data to other regulatory authorities around the world as well.
Booster study data
Unlike the US, the EMA has not yet authorized a booster dose for any COVID-19 vaccine or populations (In the US, Pfizer and Moderna have both received authorizations for limited use among vulnerable groups)
Separately, another EU agency - the European Center for Diseases Prevention and Control (ECDC) – last week suggested booster doses should be considered for immunocompromised individuals; but said there was no urgent need for booster doses in the general population.
Moderna's Phase 2 study of mRNA-1273 was amended to offer a booster dose of mRNA-1273 at the 50 µg dose level to interested participants six months following their second dose (neutralizing antibody titers were found to have waned significantly prior to boosting at approximately six months).
A booster dose of mRNA-1273 at the 50 µg dose level boosted neutralizing titers significantly above the Phase 3 benchmark. After a third dose, a similar level of neutralizing titers was achieved across age groups, notably in older adults (ages 65 and above). The safety profile following dose 3 was similar to that observed previously for dose 2 of mRNA-1273. Data is now to be submitted to a peer-reviewed publication.
An additional analysis showed that a booster dose induced robust antibody responses and significantly increased geometric mean titers for all variants of concern including Beta (B.1.351) by 32- fold, Gamma (P.1) by 43.6-fold and Delta (B.1.617.2) by 42.3-fold.
“We are pleased to submit for a conditional marketing approval with the EMA for our booster candidate at the 50 µg dose level. The amended Phase 2 study and additional analyses shows that a 50 µg booster dose of our COVID-19 vaccine induces robust antibody responses against the Delta variant,” said Stéphane Bancel, Chief Executive Officer of Moderna.
“We remain committed to staying ahead of the virus and following the evolving epidemiology of SARS-CoV-2.”