Third Dose of Pfizer Shot 95.6% Effective

"A third dose of the Covid-19 vaccine from Pfizer Inc. and BioNTech SE was found in a large study to be highly protective against symptomatic Covid-19, the companies said.

 

Researchers found 109 cases of symptomatic Covid-19 among study subjects who received a placebo shot, compared with five cases in people who took the vaccine, resulting in 95.6% efficacy, the companies said.

 

The additional dose was safe and tolerable, and consistent with what was known about the vaccine, the companies said.

The study was carried out while the highly contagious Delta variant was prevalent, the companies said, suggesting the booster helps protect against the contagious strain.

"These results provide further evidence of the benefits of boosters as we aim to keep people well-protected against this disease," said Albert Bourla, Pfizer's chief executive officer.

The results were the first from a study testing whether an additional dose of a Covid-19 vaccine provides protection in people. Until now, companies have reported a booster increased antibody levels but haven't tied the immune response specifically to whether that meant increased protection.

Based on the antibody data, U.S. health authorities in September authorized a third dose of the Pfizer-BioNTech vaccine for adults 65 years and older and others at high risk.

The data could help the Food and Drug Administration as it weighs whether to broaden Pfizer's booster use beyond the seniors and high-risk people permitted under current authorization.

The companies said they planned to submit the data to health authorities in the U.S. and other countries.

The companies provided few medical details. The results haven't been published in a peer-reviewed medical journal.

 

In the study, the companies enrolled more than 10,000 people who were 16 years and older and had received the two-dose shot.

 

The protection from the vaccine was consistent across age, sex, race, ethnicity and comorbidities, the companies said." [1]

Still 4.4% of symptomatic cases left.

1. U.S. News: Third Dose of Pfizer Shot 95.6% Effective
Hopkins, Jared S.  Wall Street Journal, Eastern edition; New York, N.Y. [New York, N.Y]. 22 Oct 2021: A.3.