Moderna has commenced its submission to the US Food and Drug Administration (FDA) for the assessment of a booster shot of its Covid-19 vaccine, mRNA-1273, at the 50µg dose level.
The company plans to make similar submissions to the European Medicines Agency (EMA), as well as other global regulatory agencies soon.
In December last year, the FDA authorised the emergency use of this messenger ribonucleic acid (mRNA) vaccine for people aged 18 years or above.
Moderna COVID-19 Vaccine encodes for a prefusion stabilised form of the Spike protein.
The submission for the vaccine booster is based on data of the 50µg dose level.
A Phase II clinical trial of the vaccine was modified to offer the 50µg booster shot to interested subjects six months after their second shot.
Findings showed that neutralising antibody titers declined before boosting at nearly six months. A 50µg booster dose improved the neutralising titers substantially above the Phase III standard levels.
Furthermore, a consistent level of neutralising titers was observed after the third shot in all age groups, especially in older adults aged 65 years or above.
The safety profile on administering the third dose was in line with that reported earlier for the second dose of the vaccine.
In another assessment, the booster shot elicited strong antibody responses and substantially elevated geometric mean titers (GMT) for all variants of concern.
The third shot increased GMT by 32, 43.6 and 42.3- fold against Beta, Gamma and Delta variants, respectively.
Moderna CEO Stéphane Bancel said: “Our submission is supported by data generated with the 50µg dose of our COVID-19 vaccine, which shows robust antibody responses against the Delta variant.
“We will continue to generate data and transparently share to support governments and regulators as they make evidence-based decisions regarding future vaccination strategies.”
Separately, the FDA plans to conduct Vaccines and Related Biological Products Advisory Committee meeting to discuss Covid-19 vaccine booster doses, particularly Pfizer-BioNTech’s supplemental biologics license application for a booster shot of their Covid-19 vaccine, Comirnaty.
Last month, the companies initiated a rolling submission of sBLA to FDA for the third dose to prevent Covid-19 in people aged 16 years or above.