Moderna’s COVID-19 Vaccine is 93 Percent Effective at Six Months, Company Still Pursuing Boosters

Moderna said that its COVID-19 vaccine is 93 percent effective six months after the second shot, but that the company is still pressing ahead on developing booster shots.

Moderna made the announcement in its quarterly earnings report yesterday, one day after the World Health Organization called for a moratorium on booster shots until every country can immunize at least 10 percent of its population.

The results come from the final analysis of a phase 3 study of mRNA-1273.

The company also announced that vaccination with three different Moderna mRNA booster candidates in a phase 2 study induced robust antibody responses against the wildtype D614G COVID-19 strain and against variants of concern including Gamma, Beta and Delta.

One of the boosters is a half dose of the regular vaccine. The other two are investigational candidates.

“Neutralizing antibody levels following the boost approached those observed after primary vaccination with two doses” of the regular Moderna vaccine, the company reported, adding that the data have been submitted to a peer-reviewed journal for publication.

In June, Moderna said it was adding two new production lines at its COVID-19 vaccine manufacturing facility in Norwood, Mass., in order to speed production of booster shots. (DID, June 22).

Moderna and Pfizer/BioNTech are the only two companies to have Emergency Use Authorization (EUA) in the U.S. for mRNA-based COVID-19 vaccines, both granted in December 2020. Johnson & Johnson’s EUA for its adenovirus-based vaccine was granted in February. Having just an EUA limits the companies’ ability to market their vaccines directly to consumers.

The FDA has not approved any COVID-19 booster shots yet.

Pfizer/BioNTech filed its Biologics License Application (BLA) for full licensure of its COVID-19 vaccine for adults in May (DID, May 10) Last month, the agency granted the vaccine a priority review for full approval (DID, Aug. 2) and that approval may be just weeks away, as reports indicate an agency-wide push to meet that goal by Labor Day — if not sooner.

Moderna, which filed its BLA on June 1 (DID, June 2), says it expects to finish the rolling submission of its application for full FDA approval this month.

J&J hasn’t yet filed a BLA for its COVID-19 vaccine. — Suz Redfearn