Pfizer Inc said on Wednesday that final results from the late-stage trial of its COVID-19 vaccine show it was 95 percent effective, adding it had the required two months of safety data and would apply for emergency U.S. authorization within days.

The final analysis comes just one week after initial results from the trial showed the vaccine was more than 90 percent effective. 

Read more: First 'milestone' COVID-19 vaccine is 90% effective, says Pfizer

The study included 170 confirmed cases of COVID-19, with the vaccine candidate demonstrating 95 percent efficacy beginning 28 days after the first dose, said Pfizer. 

The observed efficacy in adults over 65 years of age was over 94 percent, it added. 

The company also said that 3.8 percent of participants experienced fatigue after receiving a second dose of the shot. No serious safety concerns were observed, it added.

Pfizer and German partner BioNTech are the first drug makers to release successful data from a large-scale clinical trial of a vaccine, with their analysis showing a much better performance than most experts had hoped for from coronavirus vaccines. 

On Monday, U.S. biotechnology company Moderna also released preliminary data, saying its COVID-19 vaccine appears to be 94.5 percent effective.

Read more: Moderna says its COVID-19 vaccine nearly 95% effective

Chinese Foreign Ministry on Wednesday also briefed the media about the country's vaccine development progress. 

After the pandemic broke out, the Chinese government at the earliest time possible laid out five technical routes including inactivated vaccines, recombinant vaccines, adenovirus-based vaccines, live-attenuated vaccines and nucleic acid vaccines, said Zhao Lijian, a spokesperson for the ministry. 

Five Chinese vaccine candidates are under clinical trials in countries including the UAE, Brazil, Pakistan and Peru, and phase one and phase two clinical trials of some other vaccines are being accelerated, Zhao told reporters. 

(With input from Reuters)