A good immune response was "consistent across age, gender, race and ethnicity demographics", Pfizer said.
The two companies also said that they have met the safety milestone required by US Food and Drug Administration. Conditional approval in the European Union could be secured in the second half of December, he added.
"If all goes well I could imagine that we gain approval (from US FDA) in the second half of December and start deliveries before Christmas, but really only if all goes positively", he told Reuters TV.
The new figures from 170 participants in their phase III clinical trial show the jab was 95 per cent effective in preventing Covid-19, with a 94 per cent effectiveness in those aged 65 and over. It also has deals with three other companies that are developing COVID-19 vaccines.More news: Canceled Pro Bowl to Take Place Virtually in Madden NFL 21
"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 chairman and CEO, said in a statement. "Today is a special day", Bucci said.
"The 94% protection for older people is key".
Approximately 40 million doses of the two vaccines, both of which require two shots about four weeks apart, will be available by the end of the year, officials said.
Pfizer and BioNTech's trial included almost 44,000 volunteers, half of whom received the vaccine.
Before the vaccine is approved, federal scientists will go through all of the testing results, ask any questions they have, and make a decision based on whether they conclude the dose is both safe and effective against coronavirus.More news: Bahrain's FM Formally Requests to Open Embassy in Israel
The Johnson & Johnson (J&J) vaccine also uses genetically-engineered adenovirus as a vector, much like the Oxford vaccine.
Pfizer is also developing temperature-controlled containers to ship its vaccine at minus-70 degrees Celsius. It can, however, be kept in normal refrigeration for up to five days, or up to 15 days in a thermal shipping box.
Moderna's vaccine can be stored for up to six months at -20C though it is expected to be stable for 30 days at normal fridge temperatures of 2 to 8 degrees Celsius (36°-46°F). The only adverse effects experienced by volunteers were fatigue and headache. Older adults reported fewer and milder side effects, the companies said.
Andrew Hill is a researcher at the University of Liverpool's department of pharmacology.
Authorization of vaccines for children will take longer.More news: Chinese Covid vax appears safe, induces immune response