Berlin: A booster dose of the COVID-19 vaccine developed by Pfizer and German partner BioNTech restored 95.6 percent efficacy against the virus, including the Delta variant, companies data from a large study show.
The companies said in a press release that the trial, which has not been peer-reviewed, tested 10,000 participants aged 16 and older and found that the booster shot had a favorable safety profile.
Dr. Walid Gellad, a professor at the University of Pittsburgh’s medical school, said there seems to be an advantage in having the third dose in the Delta wave for symptomatic COVID-19.
“I’m just still very curious if it’s primarily in people who are much, much older. Because what we do not want to do is run dry and give boosters to 25-year-olds who had COVID before and received two doses of the vaccine, just based on this press release, ”said Gellad.
Pfizer had said the effect of its two-shot vaccine was declining over time, citing a study that showed 84 percent efficacy from a peak of 96 percent four months after a second dose. Some countries had already begun plans to provide booster doses.
The results of the trial come a day after the US Food and Drug Administration approved booster doses of the COVID-19 vaccines from Moderna and Johnson & Johnson, saying Americans could choose a different shot than their original vaccine as a booster.
The Agency approved previous boosters of Pfizer / BioNTech shots at least six months after the first round of shots to increase protection for people aged 65 and over, those at risk of serious illness and those exposed to the virus through their work.
The drug manufacturers said Thursday, local time, the median time between the second dose and the booster shot or placebo in the study was about 11 months, adding that there were only five cases of COVID-19 in the booster group compared to 109 cases in the group receiving placebo shots .