Coronavirus: what we know from Professor Raoult's second study, which again concludes that chloroquine is effective against Covid-19?
The highly publicized infectious disease specialist claims to have new evidence that chloroquine can treat patients with Covid-19. He conducted a new test on 80 people and publishes very conclusive results. But his colleagues continue to remain skeptical
Despite criticisms of the methodology of his first study, Professor Didier Raoult has continued his research.
A second study, published online on Friday, March 27 by the team of the microbiology professor, would support his thesis that chloroquine (coupled with an antibiotic, azithromycin) is effective in the fight against the epidemic of Covid-19.
A specialist in infectious diseases in Marseille, Didier Raoult proclaims that, after having tested this antimalarial drug on 24 patients during a first trial. According to him, three quarters were cured after six days. If Olivier Véran, the Minister of Health, gave the green light "so that a larger trial by other teams can be initiated as soon as possible on a larger number of patients", the scientific community criticized Professor Raoult's haste and method, because it lacks rigor.
Chloroquine would be effective only combined with an antibiotic
The 80 patients in this new study received a combination of chloroquine and azithromycin, a pulmonary antibiotic. "We are demonstrating that the combination of the two treatments has a synergistic effect which completely inhibits replication of the virus," said the research team. According to them, used separately, "hydroxychloroquine and the antibiotic have little or no effect on viral production".
This formula is one of the five treatments currently being tested in the European clinical trial Discovery. It was launched in several countries on 3,200 patients - including 800 serious cases in France. However, the first results are not expected before two weeks.
Before the administration of the treatment, the cardiac risks of the patients were controlled: the combination of plaquenil and azithromycin may indeed increase them. Patients were then treated five days after the onset of symptoms, which usually started five to six days after infection.
Out of 80 cases, 78 patients recovered (but a majority had a mild form of Covid-19)
"The majority of patients (81.3%) had favorable results and left our unit with low infection scores. Only 15% required oxygen therapy," said the study. Of the 80 patients, 65 left without worsening of their symptoms. Twelve had to be put on oxygen, but were also cured. Three others went to the intensive care unit - two are now cured, and a 74-year-old man is still there. An 86-year-old patient died on arrival at the IHU Méditerranée.
However, healing patients, even those with a mild form, can be helpful in fighting the epidemic since it helps prevent contagion and complications. Professor Didier Raoult has also always indicated that chloroquine was only effective at the first stage of infection.
Criticized for its lack of rigor during the publication of his first study, Professor Didier Raoult this time followed more the methodological recommendations - even if, this time again, it was not submitted to a scientific reading committee before its publication on the Science Direct site, recognized as serious by the community and which provides free access to summaries of scientific articles.
The presentation also follows the editorial rules of scientific publications, « developing background, methods and procedures used, results obtained, contradictory debate and table of references that allow other teams to replicate the study »..
It was written in English and co-signed by thirteen researchers from the IHU Méditerranée Infection and the Mephi research unit (Microbes Evolution Phylogeny and Infection) from Aix-Marseille University.
No conclusion possible due to the absence of a control group
Main defect of this study (which was also that of Professor Raoult's first study): no control group was set up as part of the clinical trial. Made up of patients who do not receive either any treatment or a placebo, this control group measures the effectiveness of the treatment tested. Without a control group, it is difficult, if not impossible, to make a comparison to determine whether the treatment is the source of the improvement in patients.
Professor Didier Raoult and his colleagues tried to make up for the lack of a control group by comparing their results to other studies, including a study carried out in Wuhan.