ABSTRACT
The COVID-19 pandemic has exemplified that rigorous evaluation in large animal models is key for translation from promising in vitro results to successful clinical implementation. Among the drugs that have been largely tested in clinical trials but failed so far to bring clear evidence of clinical efficacy is favipiravir, a nucleoside analogue with large spectrum activity against several RNA viruses in vitro and in small animal models. Here, we evaluate the antiviral activity of favipiravir against Zika or SARS-CoV-2 virus in cynomolgus macaques. In both models, high doses of favipiravir are initiated before infection and viral kinetics are evaluated during 7 to 15 days after infection. Favipiravir leads to a statistically significant reduction in plasma Zika viral load compared to untreated animals. However, favipiravir has no effects on SARS-CoV-2 viral kinetics, and 4 treated animals have to be euthanized due to rapid clinical deterioration, suggesting a potential role of favipiravir in disease worsening in SARS-CoV-2 infected animals. To summarize, favipiravir has an antiviral activity against Zika virus but not against SARS-CoV-2 infection in the cynomolgus macaque model. Our results support the clinical evaluation of favipiravir against Zika virus but they advocate against its use against SARS-CoV-2 infection.
Subject(s)
COVID-19 Drug Treatment , Zika Virus Infection , Zika Virus , Amides , Animals , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Humans , Macaca fascicularis , Pandemics , Primates , Pyrazines , SARS-CoV-2 , Zika Virus Infection/drug therapyABSTRACT
The emerging coronavirus called SARS-CoV-2 has spread rapidly around the world. Responsible for severe pneumonitis (Covid-19), there are also doubts concerning a possible mother-to-fetal transmission of this virus. Current data are patchy and obtained from small groups of patients. They tend to support the idea that the mother-to-fetal transmission of SARS-CoV-2 is very rare, but the period between infection and childbirth was often very short and may not allow sufficient replication to consider transplacental passage. Here, we reviewed the existing virological data and those remaining to explore. Thus, the natural history of SARS-CoV-2 infection in pregnant women and the risk of transmission in utero is not yet fully understood and defined. Four months from the emergence of this virus, it is therefore reasonable to wait for the results of specific studies on larger cohorts which, to be conclusive, must meet the best scientific criteria.
ABSTRACT
The emerging coronavirus called SARS-CoV-2 has spread rapidly around the world. Responsible for severe pneumonitis (Covid-19), there are also doubts concerning a possible mother-to-fetal transmission of this virus. Current data are patchy and obtained from small groups of patients. They tend to support the idea that the mother-to-fetal transmission of SARS-CoV-2 is very rare, but the period between infection and childbirth was often very short and may not allow sufficient replication to consider transplacental passage. Here, we reviewed the existing virological data and those remaining to explore. Thus, the natural history of SARS-CoV-2 infection in pregnant women and the risk of transmission in utero is not yet fully understood and defined. Four months from the emergence of this virus, it is therefore reasonable to wait for the results of specific studies on larger cohorts which, to be conclusive, must meet the best scientific criteria.