ALL NEWS

CDC study finds Pfizer, Moderna vaccines are 90% effective after two doses in real-world conditions

Mar 29, 2021, 3:31 PM

Full vaccination or a weekly negative Covid-19 test will be required by Jan. 4th. (Photo by Chip So...

Full vaccination or a weekly negative Covid-19 test will be required by Jan. 4th. (Photo by Chip Somodevilla/Getty Images)

(Photo by Chip Somodevilla/Getty Images)

(CNN) — Under real-world conditions, the Pfizer and Moderna COVID-19 vaccines provide highly effective protection, according to a new report from the US Centers for Disease Control and Prevention.

At full vaccination, the vaccines were 90% effective at preventing infections, including infections that had no symptoms. At least 14 days after the first dose but before the second dose, they were 80% protective, according to the agency’s Morbidity and Mortality Weekly Report published Monday. The CDC said it is the first of many planned COVID-19 vaccine effectiveness studies.

CDC vaccines study

The study looked at how the vaccines protected nearly 4,000 health care workers and first responders. The volunteers in the study worked in eight locations around the country and had been observed from mid-December to mid-March.

The CDC tested volunteers routinely regardless of symptoms. The CDC also monitored the volunteers through text messages, e-mail and direct medical reports. The volunteers also did a nasal swab once a week.

Most of the volunteers, more than 62%, had received both doses of either a Pfizer or Moderna COVID-19 vaccine. More than 12% had received just a single dose.

Among the 2,961 people vaccinated with one or more doses and the 989 unvaccinated participants, a total of 205 had a positive PCR test for COVID-19. One hundred sixty-one infections were identified when participants were unvaccinated; eight were identified among those partially immunized and three were identified among those fully immunized — more than 14 days after their second dose of vaccine. Thirty-three identified cases were excluded because the person’s immune status was not clear.

More than 87% of COVID-19 cases had symptoms. Nearly 23% of the cases sought help from a doctor. There were two hospitalizations, but no deaths.

The results of this study are similar to what scientists saw in clinical trials for the vaccines, but studies like this are important to show how effective the vaccines are, particularly in a population that, through their work, can encounters a large number of people who have COVID-19.

The results showing the level of protection from a single dose after two weeks are similar to findings from other recent studies in the UK and Israel.

“Reducing the risk for transmissible infection, which can occur among persons with asymptomatic infection or among persons several days before symptoms onset, is especially important among health care personnel, first responders, and other essential and frontline workers given their potential to transmit the virus through frequent close contact with patients and the public,” the report concluded.

“This study is tremendously encouraging,” CDC Director Dr. Rochelle Walensky said Monday at the White House COVID-19 briefing. “These findings also underscore the importance of getting both of the recommended doses of the vaccine in order to get the greatest level of protection against Covid-19, especially as our concerns about variants escalate.”

“Our national vaccination efforts are working,” Walensky added.

The US has made a big push to get people vaccinated. As of Monday, nearly 29% of the US population — more than 95 million people — have received at least one dose, and nearly 16% of the population — about 52.6 million people — are fully vaccinated, CDC data shows. Among those 18 and older, more than 1 in 5 are fully vaccinated.

“Get vaccinated when you can,” Walensky said. “So that all those people that we all love will still be here when this pandemic ends.”

The-CNN-Wire
™ & © 2021 Cable News Network, Inc., a WarnerMedia Company. All rights reserved.

We want to hear from you.

Have a story idea or tip? Send it to the KSL NewsRadio team here.

All News

...

Alex Cabrero

South Jordan residents react to thousands of tumbleweeds in front of their homes

As heavy winds blew through a Daybreak neighborhood in South Jordan, avoiding tumbleweeds kind of became a sport.

28 minutes ago

Salt Lake City International Airport is also being impacted by the winterstorm moving through Utah....

Mark Jones

Delays, cancelations reported at Salt Lake City International Airport

As of 7:40 p.m. on Saturday, airport officials said 146 flights had been delayed, which is 39% of the departing flights.

42 minutes ago

Crews working on a power pole that was damaged when heavy winds blew through the area near Shivwits...

Derrick Jones

Power restored to thousands, work continues, after winter slams Utah

Rocky Mountain Power attributed the outages to power lines downed or damaged by the wind and snow.

5 hours ago

Dusk on the last day of the 2024 legislative session at the Utah Capitol in Salt Lake City on Frida...

Bridger Beal-Cvetko

The Utah 2024 Legislative Session is over. Here’s what lawmakers did

Utah lawmakers made the most out of the 2024 general legislative session, passing 591 bills, surpassing last year's previous high of 575.

8 hours ago

Tumbleweeds surround an Eagle Mountain home on March 2, 2024. (Photo credit: Brennen Katsos)...

Josh Ellis

High winds hit Wasatch Front as storm moves in

Winds will continue to increase over western Utah valleys Saturday ahead of a front and spread into southern Utah.

8 hours ago

A lone camper truck moves north bound on the I-80 at the Donner Pass Exit on Friday, March 1, 2024,...

SCOTT SONNER, Associated Press

Blizzard ‘as bad as it gets’ hits California, Nevada. Strip of I-80 shut down

The National Weather Service has issued a blizzard warning through Sunday for a 300-mile stretch of the mountain range.

8 hours ago

Sponsored Articles

Mother and cute toddler child in a little fancy wooden cottage, reading a book, drinking tea and en...

Visit Bear Lake

How to find the best winter lodging in Bear Lake, Utah

Winter lodging in Bear Lake can be more limited than in the summer, but with some careful planning you can easily book your next winter trip.

Happy family in winter clothing at the ski resort, winter time, watching at mountains in front of t...

Visit Bear Lake

Ski more for less: Affordable ski resorts near Bear Lake, Utah

Plan your perfect ski getaway in Bear Lake this winter, with pristine slopes, affordable tickets, and breathtaking scenery.

front of the Butch Cassidy museum with a man in a cowboy hat standing in the doorway...

Bear Lake Convention and Visitors Bureau

Looking Back: The History of Bear Lake

The history of Bear Lake is full of fascinating stories. At over 250,000 years old, the lake has seen generations of people visit its shores.

silhouette of a family looking over a lake with a bird in the top corner flying...

Bear Lake Convention and Visitors Bureau

8 Fun Activities To Do in Bear Lake Without Getting in the Water

Bear Lake offers plenty of activities for the whole family to enjoy without having to get in the water. Catch 8 of our favorite activities.

Wellsville Mountains in the spring with a pond in the foreground...

Wasatch Property Management

Advantages of Renting Over Owning a Home

Renting allows you to enjoy luxury amenities and low maintenance without the long-term commitment and responsibilities of owning a home.

Clouds over a red rock vista in Hurricane, Utah...

Wasatch Property Management

Why Southern Utah is a Retirement Paradise

Retirement in southern Utah offers plenty of cultural and recreational opportunities. Find out all that this region has to offer.

CDC study finds Pfizer, Moderna vaccines are 90% effective after two doses in real-world conditions