If Moderna Inc’s Covid-19 vaccine proves to be at least 70 per cent effective, the company plans to seek emergency authorisation for its use in high-risk groups, the company’s chief executive Stephane Bancel told Reuters.

Moderna’s vaccine candidate — mRNA-1273 — is nearing the finish line in its push to enroll 30,000 individuals in a late-stage trial of a novel coronavirus vaccine. But the company may be able to declare victory early if it is able to show that people who got the vaccine fared much better in its trial that people who didn’t.

Vaccines must demonstrate they are at least 50 per cent more effective than a placebo to be considered for approval. To prove that, government officials have said, at least 150 Covid-19 infections must be recorded among trial participants with at least twice as many occurring among the placebo group.

An independent safety board will take a first look at Moderna’s data as soon as a total of 53 people in the trial become infected with Covid-19. Moderna is projecting the interim analysis will occur in November, but it could come as early as October. If most of the people who got sick got the placebo shot, that would indicate the vaccine was protecting those inoculated and could be enough evidence to seek US regulatory approval for Emergency Use Authorisation (EUA).

“If the interim readout is deemed by the independent safety committee as positive with 70 or 80 or 90 per cent efficacy, we will indeed consider approval,” Bancel said. “At such a level of efficacy, if we get there, we can protect a lot of lives…,” Bancel said.