The drugmaker Pfizer announced that early analysis of its coronavirus vaccine trial suggested the vaccine was robustly effective in preventing Covid-19.
If the results hold up, that level of protection would put it on par with highly effective childhood vaccines for diseases such as measles. No serious safety concerns have been observed, the company said.
Pfizer plans to ask the Food and Drug Administration for emergency authorization of the two-dose vaccine later this month after it has collected the recommended two months of safety data. By the end of the year it will have manufactured enough doses to immunize 15 to 20 million people, company executives have said.