FILE - This Thursday, March 18, 2021 file photo shows syringes filled with the Moderna COVID-19 vaccine at a pop up site in the Queens borough of New York. According to results released on Monday, March 29, 2021, The U.S government’s first look at the real-world use of COVID-19 vaccines found their effectiveness was nearly as robust as it was in controlled studies. (AP Photo/Mary Altaffer)

FILE - This Thursday, March 18, 2021 file photo shows syringes filled with the Moderna COVID-19 vaccine at a pop up site in the Queens borough of New York. According to results released on Monday, March 29, 2021, The U.S government’s first look at the real-world use of COVID-19 vaccines found their effectiveness was nearly as robust as it was in controlled studies. (AP Photo/Mary Altaffer)

COVID vaccine found highly effective in real-world U.S. study

The two vaccines available since December — Pfizer and Moderna — were highly effective at 90% after two doses,

The U.S. government’s first look at the real-world use of COVID-19 vaccines found their effectiveness was nearly as robust as it was in controlled studies.

The two vaccines available since December — Pfizer and Moderna — were highly effective at 90% after two doses, the Centers for Disease Control and Prevention reported Monday. In testing, the vaccines were about 95% effective in preventing COVID-19.

“This is very reassuring news,” said the CDC’s Mark Thompson, the study’s lead author. “We have a vaccine that’s working very well.”

The study is the government’s first assessment of how the shots have been working beyond the drugmakers’ initial experiments. Results can sometimes change when vaccines are used in larger, more diverse populations outside studies.

With nearly 4,000 participants from six states, the study focused on health care workers, first responders and other front-line workers who had first priority for the shots because they are at higher risk. They were given nasal swab test kits to use every week to check for signs of a coronavirus infection.

“The evidence base for (currently available) COVID-19 vaccines is already strong, and continues to mount ever higher with studies like this one,” said David Holtgrave, dean of the University at Albany’s School of Public Health, in an email.

The study included roughly 2,500 volunteers who had completed two vaccine doses, about 500 who got one dose and about 1,000 who did not get vaccinated between mid-December and mid-March.

The researchers counted 205 infections, with 161 of them in the unvaccinated group. Of the remaining 44, the CDC said 33 of them were in people apparently infected within two weeks of a shot. Experts say it takes two weeks before a dose takes full effect.

No one died, and only two were hospitalized. Thompson did not say whether the people hospitalized were vaccinated or not.

Besides the 90% figure for two doses, the study found it was 80% effective for participants two weeks or more after a first dose.

CDC Director Dr. Rochelle Walensky called the study’s findings “tremendously encouraging.”

“Our national vaccination efforts are working,” she said during a White House press briefing Monday. She added that over 93 million Americans have received at least one vaccine dose and over 51 million people have been fully vaccinated.

Different researchers have tried to look at how the vaccines have performed in real-life conditions, including work done in Israel and the United Kingdom, and a U.S. study of Mayo Clinic patients.

Unlike the Mayo study, which focused on hospitalization and death, the CDC study looked for any infection — including infections that never resulted in symptoms, or were detected before people started feeling sick.

About two-thirds of the vaccinations in the study were Pfizer shots, one-third were Moderna and five people got the newest single-dose shot from Johnson & Johnson. The study was done in Miami; Duluth, Minnesota; Portland, Oregon; Temple, Texas; Salt Lake City; and Phoenix and other areas in Arizona.

Moderna, meanwhile, announced Monday that it had shipped its 100 millionth dose to the U.S. government, meeting its pledge to supply that amount by the end of March. The company said it expects to meet its next deadlines, of delivering another 100 million doses by the end of May and its final 100 million by the end of July.

READ MORE: B.C.’s frontline worker vaccine program in flux as AstraZeneca use paused for under-55s

___

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.

Mike Stobbe, The Associated Press


Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Coronavirusvaccines

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Katherine Swampy
Maskwacis chiefs are opposed to RAPID Response

Alberta Treaty 6 First Nations say they were not properly consulted

UCP Lacombe-Ponoka MLA Ron Orr spoke to the Ponoka Chamber about the potential a new provincial government would provide to help support small business.
File photo
MLA Ron Orr: ‘Our constituents … want us to defend their livelihoods and freedoms’

Lacombe-Ponoka MLA stands with 15 other UCP members calling out retreat on restrictions

Conservative leader Erin O’Toole holds a press conference on Parliament Hill in Ottawa on Tuesday, April 6, 2020. Top Tory leaders of past and present will speak with supporters today about what a conservative economic recovery from COVID-19 could look like. THE CANADIAN PRESS/Sean Kilpatrick
O’Toole to vote against Conservative MP’s private bill on ‘sex-selective abortion’

Erin O’Toole said he supports a woman’s right to choose and will personally vote against the private member’s bill

(Government of Canada)
Liberal MP caught stark naked during House of Commons video conference

William Amos, in Quebec, appeared on the screens of his fellow members of Parliament completely naked

Health Canada headquarters in Ottawa. (Sean Kilpatrick/The Canadian Press)
Health Canada releases guidelines for reducing COVID-19 transmission at home

Improve indoor air quality by opening up your windows and doors, among the encouraged ventilation measures

Alberta Premier Jason Kenney updates media on measures taken to help with COVID-19, in Edmonton on Friday, March 20, 2020. Alberta is set to join three other provinces in exploring the feasibility of small modular reactors as a clean energy option. THE CANADIAN PRESS/Jason Franson
Four provinces to sign memorandum of understanding to explore small nuclear reactors

Alberta government said in August that it would enter into the agreement to help diversify its energy sector

Sharis Carr, a nurse at the Aaron E. Henry Community Health Service Center in Clarksdale, Miss., holds a box containing doses of the Johnson & Johnson COVID-19 vaccine Wednesday, April 7, 2021. The U.S. is recommending a “pause” in using the single-dose Johnson & Johnson COVID-19 vaccine to investigate reports of potentially dangerous blood clots. (AP Photo/Rogelio V. Solis)
EXPLAINER: What’s known about COVID vaccines and rare clots

These are not typical blood clots – they’re weird in two ways

File photo
City of Wetaskiwin awarded $5.1 million grant for additional RCMP officers

10 Additional RCMP officers to serve the City of Wetaskiwin as a result of the grant.

Titanic was the largest and most luxurious ship in the world. Photo provided and colourized by Jiri Ferdinand.
QUIZ: How much do you know about the world’s most famous shipwreck?

Titanic sank 109 years ago today, after hitting an iceberg

A health-care worker holds up a vial of the AstraZeneca Covishield vaccine at a COVID-19 vaccination clinic in Montreal, Thursday, March 18, 2021. THE CANADIAN PRESS/Paul Chiasson
PHAC receives first report of blood clot linked to AstraZeneca

The federal agency says the person is now recovering at home

A real estate sign is pictured in Vancouver, B.C. THE CANADIAN PRESS Jonathan Hayward
1 in 3 young Canadians have given up on owning a home: poll

Data released Monday says 36% of adults younger than 40 have given up on home ownership entirely

Most Read