The Covid-19 vaccine from Pfizer and BioNTech is 95% effective and has passed its safety checks, according to further data released by Pfizer.
The pharmaceutical giant and its partner BioNTech published interim results last week showing the vaccine could prevent more than 90% of people developing Covid-19.
That data was based on the first 94 volunteers to develop Covid-19, but further figures released today are based on the first 170 cases of the virus in the clinical trial.
The vaccine has been tested on 43,500 people in six countries and no safety concerns have been raised.
Pfizer and BioNTech expect to be able to produce up to 50 million vaccine doses globally in 2020 and up to 1.3 billion in 2021.
Pfizer chief executive Albert Bourla said the firm is preparing to file for emergency use authorisation from the US Food and Drug Administration.
Another vaccine, from US firm Moderna, was shown this week in early data to be almost 95% effective.