Coronavirus vaccine (illustrative)
Coronavirus vaccine (illustrative)Reuters

Moderna has said that its booster vaccine is effective against the Delta coronavirus variant, NBC News reported.

The study, released Thursday, presented the findings of a Phase 2 trial testing a 50-microgram dose of three candidates for a booster vaccine in previously vaccinated individuals. All of the boosters produced encouraging immune response against three coronavirus variants, including the Delta variant.

These immune responses were similar to the immune response seen in previously-unvaccinated individuals who had received two 100-microgram doses, Moderna explained.

In a statement quoted by NBC, Moderna wrote: "While we see durable Phase 3 efficacy through 6 months, we expect neutralizing titers will continue to wane and eventually impact vaccine efficacy. Given this intersection, we believe dose 3 booster will likely be necessary prior to the winter season."

Noting that their vaccine produces a "robust" immune response, the company also said that its Phase 3 study found the two-dose vaccine to be 93% effective, and that efficacy "remained durable" for at least six months following the second dose.

The findings have been submitted to a peer-reviewed journal for publication.