LONDON (AP) – AstraZeneca’s COVID-19 vaccine has provided strong protection against disease and has eliminated hospitalizations and deaths from the disease, including in older adults, in the final stages of testing in the United States, the company announced on Monday.
AstraZeneca said its experts have not identified any safety concerns related to the vaccine, including the undiscovered increased risk of rare blood clots identified in Europe. The question now is whether the findings will help rebuild public confidence in the vaccine worldwide, as the company seeks clearance in the United States.
In a statement, AstraZeneca said that its COVID-19 vaccine was 79% effective in preventing symptomatic COVID-19 and was 100% effective in stopping serious illnesses and hospitalization, although it has not yet published complete data, so it is not clear whether there was severe enough cases to make that discovery meaningful. The researchers said the vaccine worked on adults of all ages, including older people – something that experts want to get better data for.
AstraZeneca’s provisional results are based on 141 cases of COVID-19, but authorities refused to tell reporters at a news conference on Monday how many study volunteers received the vaccine and how many of those who received false injections.
“These findings confirm previous observed results,” said Ann Falsey, of the University of Rochester School of Medicine, who helped conduct the study. “It is exciting to see similar efficacy results for the first time in people over 65.”
AstraZeneca will apply for authorization to use the vaccine in the United States from the Food and Drug Administration in the first half of April, Ruud Dobber, the company’s executive vice president, told reporters on Monday. An FDA advisory committee will publicly debate the evidence behind the shots before the agency decides whether to allow emergency use. Dobber said that if the FDA approves the vaccine, the company will deliver 30 million doses immediately – and another 20 in the first month.
The AstraZeneca injection, which has been authorized in more than 70 countries, is a pillar of a UN-supported project known as COVAX that aims to bring COVID-19 vaccines to the poorest countries, and has also become a key tool in European countries. efforts to boost their slow vaccine implementations. But the confidence in the shot was hit repeatedly due to concerns about how the data was reported from some previous studies, confusion about its effectiveness in older adults and a recent fear of clotting.
Stephen Evans, of the London School of Hygiene & Tropical Medicine, said the new data may help to dispel concerns about the vaccine.
“The benefits of these results will be mainly for the rest of the world, where confidence in the AZ vaccine (AstraZeneca) has declined, largely due to political and media comments,” he said.
The study involved more than 30,000 volunteers, two-thirds of whom received the vaccine, while the rest received false injections. Two doses were administered to people four weeks apart.
Dr Paul Hunter, professor of medicine at the University of East Anglia, said the results are reassuring, but more details are needed to support AstraZeneca’s claim that the vaccine was completely effective in preventing serious illness and hospitalization.
“It would be nice to know how many serious cases occurred in the control group and what the confidence intervals are for that 100% value,” said Hunter, who was not connected to the study. “But that should increase confidence that the vaccine is doing what is most needed.”
Scientists hoped the US study would clear up some of the confusion about how well injections really work, especially in older people. Previous research has suggested that the vaccine was effective in younger populations, but there was no solid data to prove its effectiveness in people over 65, usually those most vulnerable to COVID-19.
Britain authorized the vaccine for the first time based on partial test results in the United Kingdom, Brazil and South Africa, which suggested that the vaccines were about 70% effective. But those results were overshadowed by a manufacturing error that led some participants to receive only half a dose on their first dose – a mistake that the researchers did not immediately recognize.
Then came more questions about how well the vaccine protected the elderly and how long to wait before the second dose. Some European countries, including Germany, France and Belgium, initially denied the injection of older adults and only reversed their decisions after new data suggested it was offering protection to the elderly.
The development of the AstraZeneca vaccine was also difficult in the USA. Last fall, the FDA suspended the company’s study for an unusual six weeks, while frustrated regulators sought information about some neurological complaints reported in Britain; ultimately, there was no evidence that the vaccine was to blame.
Last week, more than a dozen countries, mainly in Europe, temporarily suspended the use of the AstraZeneca vaccine after reports that it was linked to rare blood clots – even with international health agencies insisting that the benefits of the vaccine outweighed the risks. On Thursday, the European Medicines Agency concluded after an investigation that the vaccine does not increase the overall risk of blood clots, but cannot rule out that it is linked to two very rare types of clots. He recommended adding an alert on these cases to the vaccine leaflet.
It is not unheard of for such rare problems to emerge as vaccines are launched, as the tests usually look at tens of thousands of people, and some problems are seen only when the injection is given to millions of people.
France, Germany, Italy and other countries later resumed the use of the shot on Friday, with senior politicians rolling up their sleeves to show that the vaccine was safe.
AstraZeneca said it will continue to analyze US data before sending it to the FDA in the coming weeks. He said the data would also be published soon in a peer-reviewed newspaper.
The AstraZeneca injection is what scientists call a “viral vector” vaccine. Vaccines are made with a harmless virus, a cold virus that normally infects chimpanzees. It acts like a Trojan horse to transport the genetic material from the coronavirus peak protein to the body, which in turn produces a harmless protein. This prepares the immune system to fight if the real virus appears.
Two other companies, Johnson & Johnson and CanSino Biologics from China, make COVID-19 vaccines using the same technology, but using different cold viruses.
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Neergaard reported from Washington.
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