A final analysis of a COVID-19 vaccine candidate produced by Pfizer and BioNTech shows that the drug is 95% effective in preventing the coronavirus, and the companies say they hope to apply for Emergency Use Authorization within "days," the company reported Wednesday.
The announcement is an improvement from an initial analysis released by the company just over a week ago that showed the drug to be 90% effective. Those results were released when it had been confirmed that 94 participants in the trial who received a shot had contracted COVID-19, and only 10% of those participants who contracted the virus had actually received the vaccine.
Updated information now shows that 170 people who participated in the trial have contracted COVID-19, which crosses the threshold for final analysis. Of those participants, 162 received a placebo shot.
Of the 20,000 participants who received the vaccine, just one has developed a severe case of COVID-19. The other seven people who received the vaccine and caught the virus are only experiencing mild symptoms.
Pfizer also added that the vaccine has proven to be 94% efficient in older people — a welcome sign, given that the virus tends to present more severe symptoms in elderly patients.
Pfizer's trial included about 40,000 participants, half of which received the vaccine, and the other half which received the placebo. The vaccine requires two shots, which need to be taken 28 days apart.
The company added that there have been no safety concerns with the vaccine. In a randomized survey of 8,000 participants, only 2% reported suffering severe fatigue, and only 4% reported suffering severe headaches. Those who say they suffered side effects only experienced them briefly after vaccination.
Wednesday's announcement means Pfizer is on track to shatter records for vaccine development, a process that typically takes several years.
Pfizer and BioNTech already have their vaccine candidate in production, meaning it will be ready for distribution as soon as the Food and Drug Administration grants Emergency Use Authorization.
Pfizer's announcement comes days after an initial analysis of a Moderna-produced vaccine was also shown to be 95% effective. Several other companies also have a COVID-19 vaccine in the works, something that health officials say is important for logistics and safety.