The two companies said the study, involving more than 10,000 participants over 16 years of age, is the first trial to look at booster doses and their efficacy.
Pfizer-Biontech noted that the study was conducted at a time when the delta mutate was the dominant smoothie in the United States.
The participants in the study received the booster doses about 11 months after they received the second dose of the vaccine, and after taking it, five people were infected with the Corona virus, which means that the effectiveness rate of the third dose in preventing the virus increased by more than 95 percent.
Pfizer CEO Albert Borla said: “These findings provide further evidence of the benefits of reinforcers in an effort to protect people well from disease.”
“In addition to our efforts to increase global access and uptake among non-vaccinators, we believe boosters play a critical role in addressing the ongoing public health threat caused by this pandemic,” Burla added.
The US Food and Drug Administration has approved giving booster doses of Pfizer-Biontech, Moderna and Johnson & Johnson vaccines to people aged 65 years and over who are at risk of severe infection due to the virus.