Covid: Pfizer’s vaccine is 95% effective according to full results.
The vaccine developed by the Pfizer/BioNTech alliance is 95% effective in preventing Covid-19, according to full results of their large-scale clinical trial, the companies announced yesterday.
The results revealed by the pharmaceutical group Pfizer yesterday are better than the partial results published last week, which already showed “more than 90%” efficacy. At 95 percent efficacy, this supports U.S. officials’ predictions that at least one vaccine will begin to be injected into the arms of Americans before the end of the year.
Specifically, 162 patients in the placebo group of the trial contracted Covid-19, compared to only eight in the vaccine group, within seven days of the second dose of the vaccine (two doses were injected, three weeks apart). The trial protocol called for evaluation of efficacy once the threshold of 170 cases was reached in both groups. Nine severe cases of Covid-19 were observed in the placebo group, only one in the vaccine group.
In total, more than 43,000 people volunteered for this trial, which started at the end of July and is expected to continue.
“Well tolerated”
Pfizer will seek marketing approval “within days” from the U.S. Food and Drug Administration (FDA), which could then give the go-ahead to market as early as December, according to Moncef Slaoui, a senior government official in charge of the government’s vaccine operation.
The effectiveness of the Pfizer/BioNTech vaccine for people over 65 years of age was “more than 94 percent,” the statement said.
This level of effectiveness, if confirmed in the population, would place the vaccine among the most effective in the world, comparable to measles, and far better than the influenza vaccine, which recently was only 19 to 60 percent effective.
The only significant side effects observed in more than 2 percent of participants were fatigue (3.8 percent) and headaches (2 percent), leading manufacturers to say that the vaccine is “well-tolerated.
Pfizer was waiting for two months of follow-up for at least half of the participants before applying for FDA approval, a milestone the group knew would be reached this week.
“The trial marks an important milestone in Pfizer’s historic eight-month quest to develop a vaccine capable of ending this devastating pandemic,” said Pfizer CEO Albert Bourla.
For Ugur Sahin, co-founder of BioNTech, the small German biotechnology company that developed the novel technology on which the vaccine is based, messenger RNA, “this success illustrates the potential of messenger RNA as a new class of drugs”.
50 million doses by the end of the year
Moderna, a U.S. company, announced on Monday similar results (94.5% efficacy) with a vaccine also based on messenger RNA. In both cases, the vaccines appeared to be particularly effective in preventing severe forms of Covid-19.
But the FDA will have to evaluate in detail the data on the efficacy and safety of both vaccines, details that have not been made public by the manufacturers. The regulator is committed to doing this as publicly as possible.
The United States, Europe, and other countries have already reserved hundreds of millions of doses of Pfizer vaccine. Pfizer plans to produce 50 million doses this year, enough to vaccinate 25 million people, and 1.3 billion by 2021.
