- BBC World News
It seems like another piece of good news in the race for a coronavirus vaccine, but like many others it should also be viewed with caution.
And it is that according to a statement published on Wednesday by the developers of the Russian vaccine Sputnik V, the preliminary results of the last phase of clinical tests of the same suggest that it has an effectiveness of 92%.
The estimate is based on preliminary data from a Phase III clinical trial involving 40,000 volunteers, of whom 16,000 have already received the two doses that make up the vaccine.
More specifically, it was “calculated based on the 20 confirmed cases of covid-19 divided between vaccinated individuals and those who received the placebo, “the statement read, signed by the Gamalaya Center for Research in Epidemiology and Microbiology and the Russian Direct Investment Fund, RDIF.
“Efficacy was demonstrated on the basis of a first interim analysis obtained 21 days after the first injection,” he adds.
For Professor Charles Bangham, Senior Lecturer in Immunology at Imperial College London, the results are reassuring insofar as they “seem to confirm that it should be possible to produce an effective vaccine against COVID-19.”
But Professor Eleanor Riley, from the University of Edinburgh, said she was concerned that the data – made public two days later If Pfizer and BioNTech highlighted the good results of trials of their own vaccine – one of several that are being developed simultaneously around the world – would have been published too soon.
“This is not a competition. We need all testing to be carried out to the highest possible standards,” Riley cautioned.
And BBC Russia journalist Olga Diakonova told BBC Mundo that two Russian scientists she had spoken to after the announcement also told her it was “too soon to consider these figures promising. “
“The RDIF evaluated the efficacy of the vaccine after the first dose of the vaccine, although it takes two doses of the vaccine and three weeks for the immune response to develop,” Diakonova added.
“So the 92% figure is based on data from people who have not even received the second component of the vaccine“, he stressed.
In contrast, Pfizer – which on Monday announced results indicating an effectiveness “of more than 90%” for the vaccine it develops with BioNTech – made its evaluation at least seven days after the application of the second component of the same.
Comparison with Pfizer
Both the RDIF and Pfizer announcements are based on preliminary data from clinical trials that have not yet concluded.
And for Professor Bangham a proper evaluation of the safety and efficacy of both vaccines will only be possible when they have been published. full trial data.
The journal Nature, however, recalled that Pfizer’s results were based on an analysis done after they had already been detected. 94 cases of covid-19 among their study participants and when 38,000 of the 43,000 participants had already received both doses.
“Pfizer had originally planned to do its first interim analysis after 32 cases, but changed course after discussions with the US Food and Drug Administration,” the magazine explained.
And as the protocol for the Sputnik V tests still has not been made publicIt is not known if a preliminary analysis was already planned in his case after only 20 cases of covid-19, or if it was rushed in reaction to the announcement of his competitors.
For Stephen Evans, an epidemiologist at the London School of Hygiene and Tropical Medicine, the low number of cases reported in the Sputnik V trial means that there is less certainty that the true efficacy of the vaccine is above 90% than in the case from Pfizer and BioNTech.
“More follow-up is needed because the results are compatible with a much lower efficiency (60%), according to these data, “he said in statements collected by the UK’s Science Media Center.
For now, the Sputnik V vaccine has not presented major safety problems either, since no “unexpected adverse events” have been recorded 21 days after the volunteers received the first of the two injections.
And the Russian researchers have already assured that their data will be published “in one of the leading medical journals Peer-reviewed International “.
“If they are positive, that will almost certainly mean there will be more than one way to protect people against coronavirus,” said BBC health reporter Philippa Roxby.
“But there is questions that still need an answer for both vaccines, for example: how well do they protect older people who are at higher risk? And for how long? “Roxby recalled.
Hundreds of vaccines are in development and about a dozen are in the final stages of testing.
So in the next few days there will surely be new announcements of other candidates competing to be the first, or the ones who generate the most confidence, in a world desperate for a vaccine.
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