AstraZeneca: US data shows vaccine effective for all ages
AstraZeneca says its COVID-19 vaccine provided strong protection against sickness and eliminated hospitalizations and deaths from the disease across all age groups in a late-stage study in the United States
March 22, 2021, 10:12 AM
5 min read
FILE - In this Friday, March 19, 2021 file photo Medical staff members administer the AstraZeneca vaccine at La Nuvola (The Cloud) convention center that was temporarily turned into a COVID-19 vaccination hub, in Rome. AstraZeneca said Monday March 22, 2021 that advanced trial data from a U.S. study on its COVID vaccine shows it is 79% effective. The U.S. study comprised 30,000 volunteers, 20,000 of whom were given the vaccine while the rest got dummy shots. (AP Photo/Gregorio Borgia)
LONDON -- AstraZeneca’s COVID-19 vaccine provided strong protection against sickness and eliminated hospitalizations and deaths from the disease across all age groups in a late-stage study in the United States, the company announced Monday.
AstraZeneca said its experts did not identify any safety concerns related to the vaccine, including finding no increased risk of rare blood clots identified in Europe.
Although AstraZeneca's vaccine has been authorized in more than 50 countries, it has not yet been given the green light in the U.S. — and has struggled to gain public trust amid a troubled rollout. The study comprised more than 30,000 volunteers, of whom two-thirds were given the vaccine while the rest got dummy shots.
In a statement, AstraZeneca said its COVID-19 vaccine had a 79% efficacy rate at preventing symptomatic COVID-19 and was 100% effective in stopping severe disease and hospitalization, though it has not yet published full data. Investigators said the vaccine was effective across all ages, including older people — something previous studies in other countries had failed to establish. Two doses of the AstraZeneca vaccine were given to people four weeks apart.
“These findings reconfirm previous results observed,” said Ann Falsey of the University of Rochester School of Medicine who helped lead the trial. “It’s exciting to see similar efficacy results in people over 65 for the first time.”
The AstraZeneca shot is a pillar of a U.N.-backed project known as COVAX that aims to get COVID-19 vaccines to poorer countries, and it has also become a key tool in European countries’ efforts to boost their sluggish vaccine rollouts.
The early findings from the U.S. study are just one set of information AstraZeneca must submit to the Food and Drug Administration. An FDA advisory committee will publicly debate the evidence behind the shots before the agency decides whether to allow emergency use of the vaccine. In the past, the time between a company revealing efficacy data and a shot being authorized in the U.S. has been about a month.
Julian Tang, a virologist at the University of Leicester who was not connected to the study, described the results as “good news” for the vaccine.
“The earlier U.K., Brazil, South Africa trials had a more variable and inconsistent design and it was thought that the U.S. FDA would never approve the use of the AZ vaccine on this basis, but now the U.S. clinical trial has confirmed the efficacy of this vaccine in their own clinical trials,” he said.
Scientists have been awaiting results of the U.S. study in hopes it will clear up some of the confusion about just how well the shots really work, particularly in older people. Previous research suggested the vaccine was effective in younger populations, but there were no solid data proving its efficacy in those over 65, often those most vulnerable to COVID-19.
Britain first authorized the vaccine based on partial results from testing in the United Kingdom, Brazil and South Africa that suggested the shots were about 70% effective. But those results were clouded by a manufacturing mistake that led some participants to get just a half dose in their first shot — an error the researchers didn’t immediately acknowledge.
