Pfizer claims to have developed a Covid-19 vaccine that is 90% effective.
This is according to the first interim results in large-scale trials of the Pfizer/BioNTech candidate.
The analysis looked at the first 94 confirmed cases of Covid-19 among the more than 43 000 volunteers who got either two doses of the vaccine or a placebo.
It found that fewer than 10% of infections were in participants who had been given the vaccine.
More than 90% of the cases were in people who had been given a placebo.
The high percentage of those protected makes the findings compelling.
Regulators have said they would approve a vaccine that is just 50% effective – protecting half of those who get it.
The pharmaceutical giant says there have been no serious side-effects so far.
Dr Albert Bourla, the Pfizer chairperson and chief executive, says: “Today is a great day for science and humanity. The first set of results from our phase 3 Covid-19 vaccine trial provides the initial evidence of our vaccine’s ability to prevent Covid-19.
“We are reaching this critical milestone in our vaccine development programme at a time when the world needs it most, with infection rates setting new records, hospitals nearing over-capacity and economies struggling to reopen.”
The trial will continue until there have been 164 confirmed cases, but a finding that 90% of infections were prevented will excite politicians and the public health sector and offers for an end to the deadly pandemic.
The phase 3 trials have involved more than 43 000 people.