Pfizer-BioNTech pharmaceutical companies announced on Thursday that its COVID-19 vaccine remains 90% effective against symptomatic disease six months after a person has received two doses of the medication.
The results of the ongoing study looked at the vaccine’s level of effectiveness in 46,307 people who enrolled in the Phase 3 trial which began in July.
The results showed that of the 927 people in the study who had a symptomatic COVID-19 infection during the six-month period after two shots were given, 850 had received a placebo instead of the Pfizer vaccine. The other 77 people who contracted the virus had been given the vaccine.
“The vaccine was 100% effective against severe disease as defined by the U.S. Centers for Disease Control and Prevention (CDC), and 95.3% effective against severe COVID-19 as defined by the U.S. Food and Drug Administration (FDA),” Pfizer and BioNTech said in a joint statement.
The vaccine, which uses a gene-based technology to direct human cells to make proteins to fight the virus, has also been shown to work against a variant of the COVID-19 virus that was first identified in South Africa.
“Thirty-two cases of severe disease, as defined by the CDC, were observed in the placebo group versus none in the BNT162b2 (South Africa variant) vaccinated group, indicating that the vaccine was 100% efficacious in this analysis against severe disease by the CDC definition,” Pfizer’s news release read. “Twenty-one cases, as defined by the FDA, were observed in the placebo group versus one case in the BNT162b2 vaccinated group, indicating 95.3% efficacy by the FDA definition.”
Pfizer’s vaccine, along with one from Moderna and one from Johnson & Johnson, is being distributed under Emergency Use Authorizations from the U.S. Food and Drug Administration. With the release of six months of research data, Pfizer will be applying for a full license to distribute the vaccine soon, the company’s CEO said.
“These data confirm the favorable efficacy and safety profile of our vaccine and position us to submit a Biologics License Application to the U.S. FDA,” Pfizer CEO Albert Bourla said in the statement.
The FDA allowed the three vaccines to be distributed after reviewing two months of trial data.
The vaccine was authorized for use in December after a Phase 3 trial found it to be 95% effective at preventing COVID-19 with symptoms.
In addition, the company said no serious safety concerns had arisen in the six months since trial participants were fully vaccinated with two doses of the vaccine.
The news comes on the heels of an announcement Wednesday that clinical trials have shown that the vaccine is 100% effective in preventing severe disease in children ages 12-15. Currently, the vaccine is approved in the United States for use in people age 16 and older.
At least one dose of the Pfizer-BioNTech vaccine has been given to nearly 77 million Americans, with 27 million of those being fully vaccinated with two doses of the medication.
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