Pfizer and BioNTech Say COVID-19 Booster Injection Show High Efficacy in Large Study

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BERLIN – A booster dose of the COVID-19 vaccine developed by Pfizer Inc and German partner BioNTech SE restored efficacy to 95.6% against the virus, including the Delta variant, data released by companies from a large I study on Thursday.

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The companies said in a press release that the trial, which has not been peer-reviewed, evaluated 10,000 participants aged 16 and over and found the booster vaccine to have a favorable safety profile.

The trial results come a day after the U.S. Food and Drug Administration authorized booster doses of COVID-19 vaccines from Moderna Inc and Johnson & Johnson, and said Americans could choose a different injection. of its original inoculation as a booster.

The agency previously authorized boosters of the Pfizer / BioNTech vaccine at least six months after the first round of injections to increase protection for people 65 years of age and older, those who are at risk for serious diseases, and those who are exposed to it. viruses through your work.

Dr. Walid Gellad, a professor at the University of Pittsburgh School of Medicine, said there appears to be a benefit to having the third dose in the delta wave for symptomatic COVID-19.

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“I’m still very curious if this occurs mainly in much older people. Because what we don’t want to do is exhaust ourselves and give boosters to 25-year-olds who had COVID before and received two doses of the vaccine, based only on this press release, ”Gellad said.

Pfizer had said that the effectiveness of its two-shot vaccine diminishes over time, citing a study that showed an 84% effectiveness from a peak of 96% four months after a second dose. Some countries had already gone ahead with their plans to administer booster doses.

Drug makers said Thursday that the median time between the second dose and the booster injection or placebo in the study was around 11 months, adding that there were only five cases of COVID-19 in the booster group, compared to 109 cases in the group that received the placebo injection.

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The median age of the participants was 53 years, with 55.5% of the participants between 16 and 55 years and 23.3% at 65 years or older.

Jefferies analyst Michael Yee said the trial results add to accumulating data that the boosters could help provide long-lasting protection against symptomatic infection.

No cases of severe illness were reported, suggesting strong protection against infection from the primary vaccination series alone, Yee wrote in a note.

The companies said they would submit the detailed trial results for peer-reviewed publication to the US FDA, the European Medicines Agency and other regulatory agencies as soon as possible.