US firm Moderna on Monday announced its experimental vaccine against Covid-19 was 94.5% effective, marking a second major breakthrough in the vaccine hunt.

Moderna released early results from a clinical trial with more than 30,000 participants, after US company Pfizer and its German partner BioNTech last week said their vaccine was 90% effective.

Both vaccines are based on a new platform called messenger RNA, which is faster to produce than traditional vaccines and effectively turn human cells into vaccine factories.


The company plans to submit applications for emergency approval in the US and around the world within weeks, and says it expects to have approximately 20 million doses ready to ship in the US by the end of the year.


The Moderna vaccine, which was co-developed by the US National Institutes of Health, is given in two doses 28 days apart, and the preliminary results are based on 95 volunteers of the 30,000 who fell ill with Covid-19.

Of the 95, 90 had been in the trial's placebo group, and five in the group that received the drug.

There were 11 people who fell severely ill, all of whom were in the placebo group.

The vaccine was well tolerated, with the majority of side-effects classed as mild or moderate.

It is not yet clear how long lasting the protection will be from either the Moderna or Pfizer vaccines, nor how well they work for the elderly, the age-group at highest risk from Covid-19.