Pfizer says early analysis shows its Covid-19 vaccine is 90% effective.
The first interim results in large-scale trials show the Pfizer/BioNTech candidate is 90% effective, according to the manufacturers, whose analysis shows a much better performance if the trend continues.
The interim 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 those who get it.
The company says there have been no serious side effects.
“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,” said Dr Albert Bourla, the Pfizer chairperson and chief executive.
“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, so there is potential for the efficacy rate to change, but a finding that 90% of infections were prevented will excite politicians and public health leaders and brings into view a potential end to the pandemic.
The phase 3 trials have involved more than 43 000 people. People from black and minority ethnic backgrounds appear to have been as well protected as everyone else, the company says.