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France 24
AstraZeneca-Oxford: storm in a glass of water around the vaccine results?
One of the main vaccines against Covid-19, the one developed by AstraZeneca and the University of Oxford, has been criticized by the publication of data on its effectiveness. A process that seems unfair, according to several scientists interviewed by France 24. It has long been the protagonist of candidate vaccines against Covid-19. Developed by the University of Oxford in collaboration with pharmaceutical giant AstraZeneca, ChAdOx1 nCoV-19 was the first to gain media attention and the first to participate in human trials. And on Monday, November 23, AstraZeneca said it was about 70% effective in protecting against Sars-CoV-2, but this vaccine has since found its way into the dock. The published data has been criticized and “confidence” in Astrazeneca’s scientific approach “has suffered,” summarizes the New York Times. Among the three groups vying to be the first to market a vaccine, AstraZeneca is the only one whose stock market value has dropped, points out the Financial Times. The other two, Moderna and Pfizer, saw their course of action increase by more than 10% after announcing that their vaccine was more than 90% effective. Assay “Error” The problems for ChAdOx1 nCov-19 began when the media took a closer look at the numbers. The announced 70% efficacy was actually an average obtained from the results of several series of injections performed with different dosages. The vaccine was actually only 62% effective when the patient received a double dose, but demonstrated 90% effectiveness when a person received a first injection of only half a dose. Confusing results that seem to indicate that the vaccine would protect better if injected less. Oxford scientists working on ChAdOx1 nCoV-19 admitted that they are unable to explain this phenomenon. Questioned by various media outlets, AstraZeneca further admitted that there had been a human “error” in the dosage of the vaccine for the trials that resulted in a 90% efficacy result. of confessions we want to hear about important tests such as those carried out on a vaccine against a virus responsible for the worst pandemic in more than a hundred years. From there, all of AstraZeneca’s claims were taken with a grain of salt, and when questions were asked, the lab admitted that all of the volunteers who participated in the study that demonstrated 90% effectiveness were under the age of 55. “The fact that this dosage has not been tested on older people, particularly vulnerable to Covid-19, could pose a problem in receiving emergency marketing authorization from the authorities,” notes the New York Times. >> Also read on France 24: “Vaccine against Covid-19: what will it be in poor countries?” The data published by the laboratory does not concern, moreover, “not a single large test like this was the case of Pfizer or Moderna”, underlines the Wired site. AstraZeneca “combined the results of two studies, one conducted in the UK and the other in Brazil, although they showed differences in the way these tests were conducted,” the site continues. “Now that we have found what appears to be a better efficacy, we need to validate it, so we need to do more studies,” group chief executive Pascal Soriot said in an interview with Bloomberg. “I don’t see it. There is nothing. to worry about “What discredits the AstraZeneca vaccine? This would be bad news for the fight against the pandemic, especially in low-income countries. The ChAdOx1 nCov-19 is based, in fact, on a less expensive technology than that used by Moderna or Pfizer and the doses could be sold for much less. Unlike the other two vaccines, the Oxford vaccine also does not need to be stored at very low temperatures, which logistically means it would be easier to distribute quickly and on a large scale. According to scientists interviewed by France 24, criticism of AstraZeneca’s announcements should not be seen as questioning the vaccine. “I don’t see anything of concern here. These are interim test results on some participants. These numbers will change rapidly as we have more data, which will allow us to have a better understanding of the effectiveness of all these vaccines,” explains Zania Stamataki. immunologist from the University of Birmingham working on the neutralization of Covid-19. Same analysis for Morgane Bomsel, virologist and research director of the CNRS and the Cochin institute. “We still don’t have enough hindsight to draw conclusions. It’s only been two weeks since these results were published, and these are just press releases,” he said. In fact, none of the teams working on these vaccines have yet published the details of their results in a scientific journal. It would therefore be urgent to wait before criticizing a particular vaccine candidate. “Scientifically, the only thing that can be said at the moment is that the three vaccines are showing encouraging signs of efficacy in protecting against Covid-19,” says Zania Stamataki. In fact, even though the Oxford vaccine was only 62% effective, that would already be very promising. “We must not forget that seasonal flu vaccines reduce the risk of getting infected by only 40% to 60%,” the University of Birmingham researcher points out. The “error” in the dosage that led to the avalanche of criticism of the results published by AstraZeneca could also be a blessing. Scientists may have unknowingly found the ideal dosage. In fact, it can be explained that by injecting less vaccine, a better immune response against the virus is obtained. One possible reason is the way vaccines like Oxford’s work: “You inject a SARS-CoV-2 protein with an adjuvant. [en l’occurrence un virus ayant des effets bénins sur l’homme, NDLR] which tells the immune system to defend itself. But if we put too much adjuvant, the body risks focusing on it and ignoring the Sars-CoV-2 protein “, synthesizes Morgane Bomsel. For her, as for Zania Stamataki, the real test for the three vaccines does not lie not in figures There are two essential questions for which there are still no answers: how long is the protection provided by these vaccines and how effective are they in the populations most at risk? Perhaps the real mistake comes from the decision of all these laboratories. publish interim results. “This is something we do regularly in science, but generally the media are not interested in it. no, which means that researchers are not used to having to explain that too many conclusions should not be drawn, “observes Zania Stamataki. But she still thinks it was necessary:” People are asked to make so many sacrifices to protect themselves from this v irus that it was important to tell them, with the supporting data, that there is real hope and that the vaccines that have shown efficacy have been developed in less than a year. “
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