ATLANTA (NewsNation Now) — The COVID-19 vaccines developed by Pfizer Inc with BioNTech SE and Moderna Inc are highly effective and reduced the risk of infection by 90% by two weeks after the second shot among healthcare personnel and first responders, according to a the U.S. study released Monday.

The findings from a study by the U.S. Centers for Disease Control and Prevention of the real-world use of these messenger RNA (mRNA) vaccines confirm what was seen in large controlled clinical trials conducted before they received emergency use authorizations from the U.S. Food and Drug Administration.

“This study shows that our national vaccination efforts are working. The authorized mRNA COVID-19 vaccines provided early, substantial real-world protection against infection for our nation’s health care personnel, first responders, and other frontline essential workers,” said CDC Director Rochelle P. Walensky, MD, MPH. “These findings should offer hope to the millions of Americans receiving COVID-19 vaccines each day and to those who will have the opportunity to roll up their sleeves and get vaccinated in the weeks ahead. The authorized vaccines are the key tool that will help bring an end to this devastating pandemic.”

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Reporting by Ankur Banerjee and Vishwadha Chander in Bengaluru; Editing by Bill Berkrot.

Reuters contributed to this report.