Pfizer’s COVID-19 Vaccine 90 Percent Effective: Initial Data

Vaccine experts say the results surpass their expectations, but the study is not complete, and the data have not been peer reviewed.

Written byMax Kozlov

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Update (November 18): After the companies concluded their Phase 3 trials and found that the vaccine is 95 percent effective in an analysis of 170 confirmed COVID-19 cases, Pfizer and BioNTech are expected to seek emergency authorization from global regulators within days. The results put the vaccine on par with competitor Moderna’s COVID-19 vaccine, which was found on Monday to be 94.5 percent effective in a preliminary analysis of 95 participants.

Preliminary data from pharmaceutical giant Pfizer and German biotechnology firm BioNTech show that their COVID-19 vaccine is more than 90 percent effective at protecting people from the infection, compared to patients who received a placebo saline shot, according to a Pfizer statement today (November 9).

“I’ve been in vaccine development for 35 years,” William Gruber, Pfizer’s senior vice president of vaccine clinical research and development, tells STAT. “I’ve seen some really good things. This is ...

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Meet the Author

Max Kozlov
Max is a science journalist from Boston. Though he studied cognitive neuroscience, he now prefers to write about brains rather than research them. Prior to writing for The Scientist as an editorial intern in late 2020 and early 2021, Max worked at the Museum of Science in Boston, where his favorite part of the job was dressing in a giant bee costume and teaching children about honeybees. He was also a AAAS Mass Media Fellow, where he worked as a science reporter for the St. Louis Post-Dispatch. Read more of his work at www.maxkozlov.com.
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