In a small trial, the Pfizer/BioNtech vaccine fully protected people from symptomatic COVID-19 caused by the worrisome B.1.351 coronavirus variant widely circulating in South Africa, the companies announced in a press release.
Though researchers will need more data to confirm the result, it is just the latest bit of positive news to come out this week about how the vaccines are performing with real-world conditions and in real-world settings.
On Monday, the Centers for Disease Control and Prevention released real-world data showing that the Pfizer/BioNTech mRNA vaccine and Moderna mRNA vaccine were, collectively, 90 percent effective at preventing infections in fully vaccinated health care, frontline, and essential workers.
On Wednesday, Pfizer and BioNtech announced that their vaccine is highly effective in adolescents 12- to 15-years old—not just the adult part of the population. And on Thursday, the companies announced the B.1.351 news as well as new data on durability. That is, the latest monitoring data on people vaccinated in a Phase III trial suggests the vaccine is still 91 percent effective at preventing symptomatic disease up to six months after the second dose. That’s longer efficacy than was previously established, but researchers will need more data still to assess efficacy beyond six months.
“The bottom line message is that vaccines work very well in the real-world setting,” top infectious disease expert Anthony Fauci said in a White House COVID-19 press briefing Friday. “They work against variants, although we need further data to confirm that. They are durable for at least six months and they work in adolescents. Very, very good reason for everyone to get vaccinated as soon as its becomes available to you.”
Strong suggestions
While all the data is good news, the variant data is particularly heartening. Numerous laboratory experiments have suggested that antibodies produced by vaccines are less potent at knocking back some of the variants, particularly B.1.351. But according to the new data released by Pfizer and BioNTech, their mRNA vaccine showed “efficacy of 100 percent.”
The assertion is based on data from 800 trial participants who live in South Africa, where B.1.351 is widely circulating. Among the 800 participants, there were nine cases of COVID-19, all of which were in people who had received a placebo. Of those nine cases, genetic analysis found that six of them were caused by the B.1.351 variant.
The numbers are small, Fauci noted in today’s press briefing. However, “they showed in the setting of the troublesome B.1.351 South African variant there were six cases in the placebo [group] and zero in the vaccinated group, strongly suggesting the efficacy of the vaccines that we’re using now against problematic variants.”
Nevertheless, earlier this week, the National Institutes of Health announced that the National Institute of Allergy and Infectious Diseases (NIAID) has begun a clinical trial of a tweaked version of the Moderna vaccine, which is specifically designed to target the B.1.351 variant. At the time, Fauci, who is the director of the NIAID, said that the trial was being done “out of an abundance of caution.”
With the variant data and the durability findings, Pfizer and BioNTech are now moving to apply to have the vaccine fully approved by the Food and Drug Administration. Currently, the regulatory agency has only granted an Emergency Use Authorization, which is a classification issued during public health emergencies and bypasses the need for the normal amount of data used to secure a full approval. EUAs expire once the emergency is over.
“These data confirm the favorable efficacy and safety profile of our vaccine and position us to submit a Biologics License Application to the US FDA,” Pfizer CEO Albert Bourla said in the release. “The high vaccine efficacy observed through up to six months following a second dose and against the variant prevalent in South Africa provides further confidence in our vaccine’s overall effectiveness.”
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