Moderna's coronavirus vaccine is "94.5% effective" in preventing infection, according to early data released by the American biotechnology company on Monday.
The results come hot on the heels of an announcement by US-based pharmaceutical company Pfizer last week that its vaccine candidate was 90% effective.
It’s just as good as it gets – 94.5% is truly outstanding," Dr Anthony Fauci, America's top infectious disease expert, said of the Moderna news.
The early results showed the vaccine protected people from getting both mild and severe forms of Covid-19, according to the company.
In Moderna’s trial, 15,000 study participants were given a placebo, which is a shot of saline that has no effect. Over several months, 90 of those people developed Covid-19.
Another 15,000 participants were given the vaccine, and five of them developed Covid-19.
Among those receiving a placebo, 11 became severely ill, but none of the participants who received the vaccine became severely ill.
The company said its vaccine did not have any significant side effects. A small percentage of those who received it experienced symptoms such as body aches and headaches.
Moderna plans to apply to the US Food and Drug Administration for authorization of its vaccine soon after it accumulates more safety data later this month.
Fauci said he expects the first vaccinations to begin “towards the latter part of December, rather than the early part of December.”
How the Moderna and Pfizer vaccine candidates compare: Moderna’s vaccine has some practical advantages over Pfizer’s. Moderna’s vaccine can be kept in a freezer that’s typically available in doctors’ offices and pharmacies, and then can be kept in the refrigerator for 30 days. Pfizer’s vaccine needs to be kept much colder, and doctors’ offices and pharmacies don’t have freezers that go that low. It then can stay in the refrigerator for only five days.