The final results from Pfizer's coronavirus vaccine trial have been released and the pharmaceutical giant says shows a 95% success rate.
It comes with two months of safety data and the company says it will apply for emergency authorization within days to use it in the United States.
Pfizer, an American company, and its German partner BioNTech -- had released their initial results only a week ago that showed 90% effectiveness.
Dozens of drugmakers and research groups have been racing to develop vaccines against COVID-19.
Pfizer's new rate would make it the highest of any candidate in late-stage clinical trials so far.
Ian Jones is a Virology professor at the University of Reading:
“The Pfizer BioNTech is probably the most well focussed of the vaccines because it uses only this thing called the receptor-binding domain. // Which means that pretty much all the antibodies that are generated are going to be neutralizing.”
Moderna Inc on Monday released preliminary data for its vaccine, showing similar effectiveness -- 94.5%.
Both have raised hopes for an end to a pandemic that has so far killed more than 1.3 million people.
Pfizer said the vaccine was well-tolerated and that the only severe adverse side-effect was fatigue, which affected 3.7% of recipients.
It added that the efficacy of the vaccine was consistent across different age and ethnic groups -- a sign that the immunization could be employed broadly around the world.
However, while some groups such as healthcare workers will be prioritized in the United States for vaccinations this year, it will likely be months before large-scale rollouts begin.