Scientists Still Have Problems With AstraZeneca and Oxford’s Vaccine Results
Buzzfeed News reporters take pride in bringing you reliable and relevant reporting about coronoviruses. To help keep this news free, become a member and sign up for our newsletter, Upcoming.
The first peer-reviewed results describing clinical trials of a COVID-19 vaccine developed by Oxford University and drug company AstraZeneca were published on Tuesday, sparking confusion and criticism among scientists in late November.
Published in the medical journal Lancet, this paper describes the vaccine trials conducted by Oxford in the UK, Brazil and South Africa. Overall, data from the UK and Brazil indicate that the vaccine was 70% effective in preventing symptomatic COVID-19. No serious security issues were reported in the three countries.
The results, announced by a press release in November, stated that the vaccine could be up to 90% effective if given half the dose for the first pill. But the group did not disclose that the data was obtained as the result of an error, and scientists later criticized trial leaders' lack of transparency and rigor.
Oxford team chief Andrew Pollard told Buzzfeed News that he hoped the paper would create concerns about the trial. "Mostly there has been the perception that we are trying to get cherry-data to get good results," he said. "But this is not the case. We have agreed in advance with the regulators to take the approach."
Nevertheless, scientists who were confused with earlier press releases are not sure their concerns have been fully addressed.
"In terms of policy formulation, 70% of the number is difficult to interpret," Natalie Dean, a biostatistician at the University of Florida who specializes in designing strategies to test vaccines against emerging diseases, Buzzfeed News reported .
"It's a mess," John Moore, a virologist at Weil Cornell Medical College in New York, who works on developing vaccines against HIV, Buzzfeed News reported. "The vaccine works, obviously," but we still don't know how good it is.
The vaccine, developed by Oxford University and its spinoff company Vacitech, is being marketed in collaboration with AstraZeneca, a British-Swedish pharmaceutical company. It includes a chimpanzee adenovirus - a group of viruses that can cause the common cold in people - engineered to make a "spike" protein from SARS-CoV-2, a virus that causes COVID-19.
Scientists and public health officials are eagerly awaiting these results because the Oxford-AstraZeneca vaccine is the most widespread COVID-19 vaccine that governments hope will eventually bring the epidemic under control.
This appeal is for the low cost of the vaccine and ease of delivery. The supply deals announced so far indicate that the Oxford-AstraZeneca vaccine is on the market for less than $ 4 per dose compared to between $ 20 to $ 25 for other vaccines with results from large-scale clinical trials Will descend, which was done by drug writer Vishal Pfizer and Modern. , Is a biotech company based in Cambridge, Massachusetts.
What's more, the Oxford-AstraZeneca vaccine can be stored at normal refrigeration temperatures, unlike Pfizer and Moderna, which must be deep frozen for some time before use - in the case of the Pfizer vaccine, around -70 Degree cellarius.
But claims of vaccine efficacy have been under a cloud since November 23, when AstraZeneca released a misleading press release describing the combined results of tests run by Oxford University in the UK and Brazil involving about 23,000 volunteers. AstraZeneca claimed "an average efficacy of 70%" based on how 131 cases of COVID-19 were distributed across the test vaccines and placebo arms.
It suggested that the vaccine was less effective than its main rivals, as Pfizer and Modern announced earlier each November that testing of their vaccines indicated they were more than 90% effective.
But in a twist, AstraZeneca and Oxford claimed that if the participants were given half the dose after the entire dose, their vaccine was also 90% effective. The two full doses, meanwhile, had only 62% efficacy. More successful results appeared prominently in his promotional push.
Pollard stated in the press release, "Encouragingly, we have found that one of our dose regimens can be approximately 90% effective and if this dosing regime is used, more people can be supplied with the vaccine. "
Scientists were initially confused by these findings. "I got results, as hard to explain," Dean told Buzzfeed News last week.
And as more details surfaced, experts increasingly doubted the 90% claim. First Pangalos, AstraZeneca's head of non-oncology research and development, admitted to Reuters that half the dose was actually the result of an error - made by Italian manufacturer Advent and first revealed by Mirror in June.
Then on November 24, with Operation War Speed, leading scientist Monsep Saloui, a partnership of the US federal government to accelerate the development of the COVID-19 vaccine, told reporters that volunteers accidentally gave the first half dose, all of them from 55 Were younger - therefore not representative of the age of the volunteers during the entire trial.
advertisement
The fact that the error affects a nonrepresentative group reflects another misleading aspect of the UK trial: Since it was first listed in ClinicalTrials.GO in late May, the number of specific patient groups in the trial There is a steady increase in, resulting in nervousness The array of 12 experimental groups and 25 subgroups each provide different treatments.
"What do these tests mean? We don't know, "Moore told Buzzfeed News last week.
In the new Lancet paper, the Oxford team statistically controlled for age differences between groups given different doses, which found that better efficacy for half-dose, full-dose treatment remains. But other scientists remain concerned that there is no data yet on how well it works in older people - those most vulnerable to COVID-19.
"It needs further evaluation," Dean said.
0 Comments