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The first results describing the clinical trials of the COVID-19 vaccine developed by Oxford University and AstraZeneca were published on Tuesday. prior notice what happened in late November sparked confusion and criticism among scientists.
The paper, Published in the medical journal Lancet, described Oxford’s vaccine trials in the United Kingdom, Brazil and South Africa. Overall, data from the UK and Brazil indicate that the vaccine was 70% for the prevention of symptomatic COVID-19. No serious security problems were reported in all three countries.
The results announced in a press release in November revealed that the vaccine could be up to 90% effective if given in the middle dose for the first shot. But the team did not report that the data was obtained as a result of a dosing error, and scientists later criticized the trial leaders for their lack of transparency and rigor.
Andrew Pollard, head of the Oxford team, told BuzzFeed News that he hopes the paper will ease concerns about the trial. “Most of the data has assumed that we are trying to collect data to find good results,” he said. “But that’s not it. We have agreed in advance with the approach to be taken with the regulators. “
However, the researchers confused the scientists before press releases they are not sure that their concerns have been fully addressed.
“When it comes to policy making, the 70% figure is difficult to interpret,” said Natalie Dean, a biostatistician at the University of Florida who specializes in designing strategies to test emerging disease vaccines.
“It’s a mess,” John Moore, a virologist at Weill Cornell Medical College in New York who works to develop HIV vaccines, told BuzzFeed News. “The vaccine works clearly, but we still don’t know how well.”
The vaccine, developed by Oxford University and the spinoff company Vaccitech, is being launched in conjunction with the British-Swedish pharmaceutical company AstraZeneca. It is made up of a chimpanzee adenovirus – a group of viruses that can cause colds in people – SARS-CoV-2, a virus that causes COVID-19, designed to make a “spike” protein.
Scientists and public health officials have been worried about these results, the Oxford-AstraZeneca vaccine has been pre-ordered among COVID-19 vaccines and governments hope to eventually control the pandemic.
The appeal lies in the low cost of the vaccine and the ease of delivery. Provisions announced so far indicate that the Oxford-AstraZeneca vaccine will be marketed for less than $ 4 per dose, ranging from $ 20 to $ 25 with the results of large-scale clinical trials, made by drug giant Pfizer and Moderna. , A biotechnology company based in Cambridge, Massachusetts.
What’s more, the Oxford-AstraZeneca vaccine can be stored at normal cooling temperatures, unlike Pfizer and Moderna, which need to be frozen until shortly before use – in the case of the Pfizer vaccine -70 degrees Celsius.
But claims about vaccine effectiveness have been under a cloud since November 23, when it was released by AstraZeneca confusing press release describes the combined test results of Oxford University in the UK and Brazil with around 23,000 volunteers. COVID-19 cases were based on 131 test vaccines and placebo arms, AstraZeneca claimed “Average efficiency of 70%”.
This suggested that the vaccine was more effective than its main rivals Pfizer and Modern each announced earlier in November that its vaccine trials were more than 90% effective.
But twice, AstraZeneca and Oxford also said their vaccine was 90%, if participants were given half and a full dose. Meanwhile, the two whole doses had only 62% efficacy. The most successful result was the boost in advertising.
“It’s exciting that we’ve found that one of our dose regimens can be around 90%, and if this dose regimen is used, more people can be included with the planned vaccine supply,” Pollard said in a press release.
Scientists were initially confused by these findings. “I found the results I found difficult to interpret,” Dean told BuzzFeed News last week.
As more details about what happened surfaced, experts became increasingly skeptical of the 90% claim. First Mene Pangalos, head of non-oncology research and development at AstraZeneca, admitted Reuters half the dose, in fact, was the result of an error in the first place the newspaper diary revealed back in June.
On November 24, Moncef Slaoui, Chief Scientist of Operation Warp Speed, cooperated with the U.S. federal government to accelerate the development of the COVID-19 vaccine, they told reporters that the volunteers gave the wrong half of the initial dose were under the age of 55, so they were not the same age as the volunteers throughout the test.
The fact that the dosing error affected a non-representative group reflects another confusing aspect of the UK trial: since it was the first Listed at ClinicalTrials.gov by the end of May, the number of specific patient groups in the trial has steadily increased, creating an astonishing set of different treatments consisting of 12 experimental groups and 25 subgroups.
“What do these tests mean? We don’t know, ”Moore told BuzzFeed News last week.
In the new Lancet paper, the Oxford team statistically monitored age differences between groups given different doses, seeing that the effectiveness of mid-dose and full-dose treatment was improved. Other scientists remain concerned that there is no data on how it works in the elderly (those who are most vulnerable to COVID-19) so far.
“It needs more evaluation,” Dean said.
Unlike Pfizer and Modern, Oxford University and AstraZeneca did not release all the details of the test protocols so that other researchers could study them at the beginning of the large-scale tests, making it difficult to understand the results presented in previous press releases. More concerns about transparency arose in September after vaccine trials had a serious backlash against an alleged UK participant. The break was made public only after the biomedical news was reported site Stat.
In a statement sent to BuzzFeed News last week, the Oxford team downplayed the significance of the dosing error and said the plan to continue the study had been cleared with UK regulatory authorities: “[W]when it was revealed that a lower dose was being used, we discussed this with the regulator and agreed on a plan to test two lower doses / higher dose and higher dose / higher dose, allowing for the inclusion of two approaches. “
The new paper warns that the protocol was changed on June 5, a week after the trial began. Pollard told reporters at the Science Media Center in London today that the change was made before the “database lockout” for the trial, which was part of an officially approved plan.
However, mixed results are unlikely to be approved by the FDA. The U.S. regulator is expected to await the results of another AstraZeneca trial currently underway in the U.S., headed by AstraZeneca instead of Oxford, before deciding whether to accept the emergency vaccine.
“What I can say is that there is a lot to do,” Paul Offit, director of the Philadelphia Children’s Hospital Vaccine Education Center and a member of the FDA’s Vaccine and Related Biological Products Advisory Committee, told BuzzFeed News last week. .
“It’s not obvious to conclude why the efficiency results appear to have been significantly different, 90% versus 62%,” Slaoui, chief scientist at Operation Warp Speed, said in a press conference on Dec. 2. it is a clear explanation based on the data and data behind these two numbers. It is very likely that the package will not have enough acceptance. “
Pascal Soriot, CEO of AstraZeneca, spoke at an appearance at the Science Media Center and said the FDA anticipated that it would request the results of the U.S. trial.
Another concern is the results in the UK and Brazilian trials designed as a separate test for vaccine efficacy, with slightly different treatment and placebo arms. It was necessary to combine the data from the two trials after the Oxford team noticed that the UK’s success in cutting COVID-19 transmission in late spring meant the UK trial did not see enough cases to get definitive results.
There was the Oxford team initially bullish COVID-19 shows an effective vaccine about the chances of being the first. “We’re probably in a position at one of the highest levels of COVID transmission in Europe at the moment, probably in Europe, so we’re pretty good at achieving efficiency over the next three months,” said Adrian Hill, director of the Jenner Institute in Oxford. he told CNN at the end of April.
A few months later, Hill he told the Telegraph newspaper: “The virus is a race against extinction and against time. At the moment, there is a 50% chance of no results. “
The stakes are high for the high expectations generated by the Oxford-AstraZeneca vaccine. This is especially true in the UK, where Prime Minister Boris Johnson is praised the work “one of our greatest scientists,” and one of his office units reported that he was encouraged to label vaccine containers with a chain of unions. According to the Huffington Post.
The barriers to emergency vaccination admission in the UK are expected to be lower than in the US. In fact, it has the nation’s Agency for the Regulation of Medicines and Health Products already accepted Pfizer vaccine, still continues to study By the FDA. The U.S. health agency’s advisory board is meeting this Thursday to evaluate the results of the Pfizer vaccine, which will be the first vaccine to receive an emergency permit in the U.S.
The UK’s acceptance of the Oxford-AstraZeneca vaccine could lead to a frustrated demand, given the cost of the vaccine and ease of delivery. According to one data analysis The life science analysis company Airfinity of the science journal Nature already has high demand, with 2.7 billion doses already pre-ordered, far more than any other vaccine candidate.
Scientists are concerned about the questions that arise about the effectiveness of the vaccine because the problems that arise later can damage the overall confidence in COVID-19 vaccines.
“Our biggest collective fear is that things that jeopardize people’s trust will go wrong,” Moore said. “We wanted the process to be as clean as possible.”
Stephanie M. Lee helped report this story.
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