For the first time, a scientific journal validated, Tuesday, December 8, a vaccine against Covid-19, that developed by AstraZeneca and the British University of Oxford.
The publication by The Lancet of these results, scrutinized by independent scientists, confirms that this vaccine is effective by 70% on average, according to what AstraZeneca announced on November 23.
It is one of the three most advanced vaccines, just one year after the onset of this new disease.
The other two are that of the American laboratory Moderna and that of the American-German alliance Pfizer / BioNTech, with which the United Kingdom began its vaccination campaign on Tuesday.
Published and studied around the world
The latter two boast an efficiency of 94.1% and 95% respectively.
Their detailed data have so far not been published in a scientific journal, but have been sent to the various drug agencies responsible for examining marketing applications.
It is on this basis that the United Kingdom has already authorized that of Pfizer / BioNTech.
The data of this vaccine were also made public Tuesday by the United States Medicines Agency (FDA), according to which it does not present a safety risk, which paves the way for its upcoming authorization in the United States.
Beyond the authorization procedures, the fact that the data is published allows scientists around the world to examine it in detail and gain a clearer idea of the efficacy and safety of vaccines.
The efficacy figures for that of AstraZeneca / Oxford relate to 11,636 volunteers in the United Kingdom and Brazil, half of whom received the vaccine and the other half a placebo.
Efficiency in question
Efficacy is calculated by looking at how many people get Covid-19 in the group of vaccinated volunteers compared to the placebo group.
Out of 131 cases of Covid-19 detected 14 days after the second injection of the vaccine, 30 came from the vaccinated group (which had 5,807 volunteers) and 101 from the placebo group (5,829), i.e. an efficiency of 70%.
This efficacy is only an average, however, as two different protocols were used during the trial.
In fact, 1,367 British volunteers first received a half dose, then a full dose a month later.
For these volunteers, the efficiency is 90%.
On the other hand, it goes down to 62% for the rest of the volunteers who were however more vaccinated, with two complete doses a month apart.
A few days after the announcement of the first results, AstraZeneca admitted that it was by mistake that only half a dose had been administered to some volunteers.
In addition, the volunteers who received the half dose were all under the age of 55, which may skew the results.
Reviews
All of this drew criticism, which prompted the laboratory to announce on November 26 that it was holding an "additional study" to verify these results.
Moreover, according to data published by The Lancet, AstraZeneca's vaccine "is safe".
Of the total of 23,754 volunteers who participated in these trials, only one patient who received this vaccine experienced a "possibly related serious adverse reaction" to this injection.
It was a case of transverse myelitis (a rare neurological impairment) which had motivated the temporary interruption of the trial in early September.
Two other cases of serious side effects were detected: one in a volunteer in the placebo group, and the other in a volunteer whose group it is not known to.
"These three participants are cured or in the process of being cured and continue to be part of the trial," according to its officials.
"We have started to submit the data to regulatory authorities around the world for rapid authorization and our production lines are operational," AstraZeneca CEO Pascal Soriot commented in a statement.
The company says it is capable of manufacturing some 3 billion doses of its vaccine in 2021.
With AFP
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