Pfizer and Moderna vaccines 80% effective at preventing COVID-19 after one shot, CDC says

Two doses showed 90% effectiveness.

Corinne Reichert Senior Editor
Corinne Reichert (she/her) grew up in Sydney, Australia and moved to California in 2019. She holds degrees in law and communications, and currently writes news, analysis and features for CNET across the topics of electric vehicles, broadband networks, mobile devices, big tech, artificial intelligence, home technology and entertainment. In her spare time, she watches soccer games and F1 races, and goes to Disneyland as often as possible.
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Corinne Reichert

The vaccines are not only effective at preventing symptoms.

Sarah Tew/CNET

A study by the US Centers for Disease Control and Prevention has shown the Pfizer and Moderna vaccines are 80% effective in preventing COVID-19 infections two weeks after getting the first shot -- and 90% effective two weeks after the second dose. Previously, the vaccines were shown to be effective in preventing the symptoms of COVID-19. This study shows they help prevent people from contracting the coronavirus. 

The CDC study followed almost 4,000 health care workers, first responders and other essential and front-line workers, giving them weekly COVID-19 tests for 13 weeks in a row after they were immunized.

Read more: 16 important do's and don'ts for getting your COVID-19 vaccine

The news comes the same day President Joe Biden announced 90% of adults will be eligible for a COVID-19 vaccine by April 19, and that the majority of Americans will have a vaccination site within 5 miles of their home. Biden had previously said all adults in the US should be eligible for a vaccine by May 1.

Here's where to get a COVID-19 shot and how to track how many vaccines are available in your state.

The information contained in this article is for educational and informational purposes only and is not intended as health or medical advice. Always consult a physician or other qualified health provider regarding any questions you may have about a medical condition or health objectives.