Pfizer Inc. has said a final analysis of clinical-trial data showed its Covid-19 vaccine was 95% effective.

The company said it planned to apply for emergency approval from the Food and Drug Administration “within days.”

The U.S. drugmaker and its partner, BioNTech SE said their vaccine protected people of all ages and ethnicities, with no significant safety problems so far in a trial that includes almost 44,000 participants.

The data showed that the vaccine prevented mild and severe forms of Covid-19, the company said. And it was 94 percent effective in older adults, who are more vulnerable to developing severe Covid-19 and who do not respond strongly to some types of vaccines.

The trial results — less than a year after researchers began working on the vaccine — shattered all speed records for vaccine development, a process that usually takes years.

“The study results mark an important step in this historic eight-month journey to bring forward a vaccine capable of helping to end this devastating pandemic,” Dr. Albert Bourla, Pfizer’s chief executive, said in a statement.

If the F.D.A. authorizes the two-dose vaccine, Pfizer has said that it could have up to 50 million doses available by the end of the year, and up to 1.3 billion by the end of next year.