In a new study, researchers examined the antiviral effect of hydroxychloroquine in macaques (a type of monkey) infected with the COVID-19 virus, used alone or in combination with drug azithromycin.
They did not find an obvious antiviral effect of the drug on COVID-19.
The research was conducted by a team at Université de Paris-Saclay and elsewhere.
The study, launched in February 2020, evaluates the antiviral effect of hydroxychloroquine against the SARS-CoV-2 virus in vivo.
The hydroxychloroquine was administered before infection, as a prophylactic treatment, or in the first days after infection to reduce the viral load.
The possible anti-inflammatory effects of hydroxychloroquine were not tested.
The study first showed the relevance of the non-human primate (NHP) model.
This showed that the disease observed in macaques is very similar to the disease observed in the majority of COVID-19 patients who do not need hospitalization.
The use of an animal model in this study was critical to characterize the pharmacokinetics of hydroxychloroquine, i.e. analyzing the concentration of hydroxychloroquine in blood and in the lung tissues, which is not feasible in humans, to ensure that it reaches sufficient levels compatible with those required to obtain an antiviral effect in the Vero cells in vitro model.
The major results of the study are that hydroxychloroquine did not protect the animals in the prophylactic setting and none of the hydroxychloroquine treatment strategies showed any significant effect on SARS-CoV-2 viral loads when compared to placebo-treated animals.
The team says this preclinical study, complementing the ongoing hydroxychloroquine clinical studies, brings new highlights in the understanding of the pathogenesis of SARS-CoV-2 infection and the value of hydroxychloroquine for preventing and treating infection in humans.
One author of the study is Pauline Maisonnasse.
The study is published in Research Square.
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