Scotland’s vaccination program substantially reduced hospital admissions for COVID-19, according to the results of a study published Monday, offering the strongest signal in the real world of the efficacy of the COVID-19 vaccine. AstraZeneca-Oxford which much of the world relies on to end the pandemic.
People receive the COVID-19 vaccine from Pfizer-BioNTech in Cardiff, Wales. Photo Andrew Testa / The New York Times.
Britain has delayed giving the second dose to three months after the first, opting to offer more people the partial protection of a single injection.
The study, which covers both the AstraZeneca vaccine and the Pfizer-BioNTech, examined the number of people who were hospitalized after receiving single dose of the vaccine.
However, the study warns about the duration of the high levels of protection from a single dose.
The risk of hospitalization was reduced from a week later people received the first injection, reaching a low point four to five weeks after vaccination.
But then it seemed increase againr.
The scientists who conducted the study said it was too early to know whether the protection offered by a single dose diminished after a month, and they cautioned that they needed more proof.
The Scotland findings reinforced previous results from Israel, which showed the vaccines offered significant protection against the virus.
Israeli studies have focused on the vaccine Pfizer, but the Scottish study was extended to injecting AstraZeneca, which has been administered in Great Britain since the beginning of January.
The AstraZeneca injection is the backbone of many countries’ vaccination plans: it is much cheaper to produce, and it can be shipped and stored in normal refrigerators rather than the ultra-cold freezers used for other vaccines.
“Both work spectacularly well”Aziz Sheikh, a professor at the University of Edinburgh who participated in the study, told a news conference on Monday.
Researchers in Scotland examined about 8,000 coronavirus-related hospital admissions and studied how the risk of hospitalization differed between people who had been vaccinated and those who had not.
In total, more than 1.1 million people they were vaccinated in the period the researchers studied.
The number of vaccinated people who sought care in hospitals was too small to compare the AstraZeneca and Pfizer vaccines, or to give precise figures on their effectiveness, the researchers said.
In that same time period, Pfizer’s vaccine reduced the risk of hospitalizations by approximately one 85 percent.
In both cases, these figures fit within a wide range of possible effects.
But 28 to 34 days after the first injection, the AstraZeneca vaccine reduced the risk of hospital admissions for COVID-19 by approximately one 94 percent.
Since the Pfizer vaccine was licensed in Britain before AstraZeneca’s, the researchers had more data on the Pfizer vaccine, and found that protection against hospital admissions was slightly reduced for longer periods after the first injection.
“ANDThe protection peak occurs at four weeks, and then it starts to decline, ”said Simon Clarke, a professor of cell microbiology at the University of Reading who was not involved in the study.
AstraZeneca’s vaccine has faced skepticism in parts of Europe after many countries chose not to give it to older people, claiming that data from clinical trials in that group were lacking.
The Scottish study was unable to provide precise figures on the efficacy of that vaccine in older people.
But the combined effect of the AstraZeneca and Pfizer vaccines substantially reduced hospital admissions for people over the age of 80.
Many older people received the AstraZeneca vaccine.
Benjamin Mueller is the UK correspondent for The New York Times. He was a reporter on police and law enforcement issues in the Metro section since 2014. @benjmueller
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