The vaccine developed by the Pfizer / BioNTech alliance is 95% safe and effective in preventing Covid-19, according to comprehensive results from their clinical trial, a level similar to Moderna’s and which increases the chances that at least one can begin to be injected into the arms of Americans before the end of the year.
The acceleration of the epidemic in the United States in recent weeks has given a boost to the clinical trials of the two companies, mechanically proving the effectiveness of their vaccines, while reassuring their safety.
The two companies have been competing for press releases for ten days and should in any case hold the first two vaccines authorized in the United States, and probably in the Western world. Others are developed by China and Russia.
Pfizer, an American giant, and BioNTech, a small German biotechnology company, announced on November 9 that their vaccine had demonstrated “more than 90%” of effectiveness, according to preliminary results relating to 94 cases of Covid-19 among participants of their trial carried out in several countries.
As of Wednesday, the total had jumped to 170 cases: 162 in the placebo group, and only 8 in the vaccinated group, for a calculated efficacy of 95%.
“Phenomenal”, tweeted Eric Topol, American expert in clinical trials.
These cases were counted within seven days of the second dose of the vaccine, which is taken in two doses three weeks apart. In total, more than 43,000 people have volunteered for the trial, which began in late July, and is expected to continue.
Another reassuring statistic: nine severe cases of Covid-19 were observed in the placebo group, against only one in the vaccinated group.
Pfizer will apply for marketing authorization “within days” from the United States Drug Administration (FDA).
The latter could then give the green light to the marketing as early as December, said Monday a senior official of the government operation for vaccines, Moncef Slaoui.
The Pfizer / BioNTech vaccine is reportedly effective across gender, age and ethnicity, with “greater than 94%” effectiveness for people over 65 years of age.
This efficacy, if confirmed in the population, would place the vaccine among the most effective in the world, comparable to that of measles, and much better than the influenza vaccine, which recently was only effective between 19 and 60 %.
The only significant side effects seen in over 2% of participants were fatigue (3.8%) and headaches (2%), leading manufacturers to claim that the vaccine is “well tolerated”.
Pfizer was waiting to have two months of follow-up for at least half of the participants before seeking clearance from the FDA, a step the group knew would be taken this week.
“The trial marks an important milestone in the historic eight-month quest to develop a vaccine capable of ending this devastating pandemic,” said Pfizer CEO Albert Bourla.
For Ugur Sahin, the co-founder of BioNTech, who developed the new technology on which the vaccine is based, messenger RNA, “this achievement illustrates the potential of messenger RNA as a new class of drugs”.
Moderna, an American company, announced on Monday similar results (94.5% effectiveness), with a vaccine also based on messenger RNA. In both cases, the vaccines appeared particularly effective in preventing severe forms of Covid-19, the disease caused by the new coronavirus.
But the FDA will need to assess in detail the data on the efficacy and safety of the two vaccines, which have not been made public by the manufacturers. The regulator is committed to doing so as publicly as possible.
The European regulator for its part examines the data continuously.
The United States, Europe, Canada, Japan and other wealthy countries have already reserved hundreds of millions of doses of one or both vaccines. But on Wednesday, Moderna had not yet signed with Brussels.
A logistical difference exists between the two vaccines: that of Pfizer is more complicated to distribute because it must be transported at -70 ° C, against -20 ° C for Moderna.