US biotech company Moderna on Monday said that its experimental coronavirus disease (COVID-19) vaccine candidate has turned out to be "94.5% effective", according to interim data from a late-stage clinical trial with more than 30,000 participants.
This makes Moderna the second US company, after Pfizer, to report results in a single week that far exceed expectations.
"This positive interim analysis from our Phase 3 study has given us the first clinical validation that our vaccine can prevent COVID-19 disease, including severe disease," said Stephane Bancel, Moderna's CEO.
According to experts, although the 94% figure is the reported efficacy bound by statistical uncertainty, the practical efficacy rate ought to be well over 85%, which is still a better shot than expected.
The news reflects optimism from public health experts who were hoping for convincing evidence regarding the late-stage clinical trials. The result is better than what was initially anticipated.
Moderna has also announced that the vaccine can be kept in a conventional freezer (-20 degrees Celsius) for up to 6 months, and that once thawed the vaccine can be kept for up to 30 days at standard refrigerator (2 to 8 degrees centigrade). This makes the vaccine much easier to deliver.
There's positive news on the side-effects front as well, as the vaccine is reported to have a range of minor adverse effects, which are "unsurprising and typical of almost any vaccine", according to experts. However, these reactions tend to be local to where the injection was given and are rarely long-lasting or severe.
Moderna's update on this day also echoes the optimism from Dr. Anthony Fauci earlier this week, that the world might finally turn the corner on the deadly pandemic.
Earlier, it was reported that the US is working with a portfolio of six vaccines, using three different platform technologies and two candidates from each platform: messenger RNA, live viral vectors and recombinant protein.
Pfizer and Moderna's vaccines use the messenger RNA platform, Johnson and Johnson and AstraZeneca in partnership with Oxford University are on the live vector path while Novavax and Sanofi/ GlaxoSmithKline are building out their vaccine candidates on the recombinant protein platform.
All six vaccines are in the "clinical development stage" and four of them are in Phase Three trials.
One of them - Pfizer - announced Monday that it has achieved 90 per cent efficacy, "demonstrating that vaccination is possible against COVID-19".
The last two vaccines - on the recombinant protein platform - plan to start their Phase Three trials within the next few weeks.
The US is ready with manufacturing capability to ramp up production as soon as any vaccine candidate demonstrates clinical efficacy and gets emergency use authorisation from the US Food and Drug Administration.