ebola virus in rhesus monkeys. travis warren, who has been a usamriid principal investigator since 2007, said that the "work is a result of the continuing collaboration between usamriid and gilead sciences". the "initial screening" of the "gilead sciences compound library to find molecules with promising antiviral activity" was performed by scientists at the centers for disease control and prevention (cdc). as a result of this work, it was recommended that remdesivir "should be further developed as a potential treatment." remdesivir was rapidly pushed through clinical trials due to the west african ebola virus epidemic of 2013–2016, eventually being used in people with the disease. preliminary results were promising; it was used in the emergency setting during the kivu ebola epidemic that started in 2018, along with further clinical trials, until august 2019, when congolese health officials announced that it was significantly less effective than monoclonal antibody treatments such as ansuvimab and atoltivimab/maftivimab/odesivimab. the trials, however, established its safety profile. hospitalized patients remdesivir was approved for medical use in the united states in october 2020. the u.s. food and drug administration (fda) approved remdesivir based on the agency's analysis of data from three randomized, controlled clinical trials that included participants hospitalized with mild-to-severe covid‑19. the fda granted approval and reissued the revised eua to gilead sciences inc. the fda approved remdesivir based primarily on evidence from three clinical trials (nct04280705, nct04292899, and nct04292730) of 2043 hospitalized participants with covid‑19. the trials were conducted at 226 sites in 17 countries including the united states. in november 2020, the world health organization (who) updated its guideline on therapeutics for covid‑19 to include a conditional recommendation against the use of remdesivir, triggered by results from the who solidarity trial. meanwhile, the public health agency of canada's covid-19 clinical pharmacology task group recommended that remdesivir only be administered to hospitalized patients as part of a randomized controlled trial due to limited information on risks and benefits. in january 2022, the canadian component of the who solidarity trial reported that in-hospital people with covid‑19 treated with remdesivir had 17% lower relative risk of death (18.7% versus 22.6% death rates) and 47% reduced relative risk for needing oxygen and mechanical ventilation (8.0% versus 15.0%) compared to people receiving standard-of-care treatments. in september 2022, the who updated their guidelines to recommend use of remdesivir for both non-hospitalized and hospitalized patients. this was based on final results from the solidarity trial that showed a reduction in mortality or progression to mechanical ventilation for non-ventilated patients. nonhospitalized outpatients in january 2022, a study indicated that nonhospitalized people who were at high risk for covid-19 progression had an 87% lower risk of hospitalization or death after a 3-day course of intravenous remdesivir. remdesivir/baricitinib in may 2020, the national institute of allergy and infectious diseases (niaid) started the adaptive covid‑19 treatment trial 2 (actt-2) to evaluate the safety and efficacy of a treatment regimen consisting of remdesivir plus baricitinib for treating hospitalized adults who have a laboratory-confirmed sars-cov-2 infection with evidence of lung involvement, including a need for supplemental oxygen, abnormal chest x-rays, or illness requiring mechanical ventilation. in november 2020, the u.s. food and drug administration (fda) issued an emergency use authorization (eua) for the drug baricitinib, in combination with remdesivir, for the treatment of suspected or laboratory-confirmed covid‑19 in hospitalized people two years of age or older requiring supplemental oxygen, invasive mechanical ventilation, or extracorporeal membrane oxygenation (ecmo). the data supporting the eua for baricitinib combined with remdesivir are based on a randomized, double-blind, placebo-controlled clinical trial (actt-2), which was conducted by the national institute of allergy and infectious diseases (niaid). the eua was issued to eli lilly and company. remdesivir/interferon beta-1a in august 2020, the niaid started the adaptive covid‑19 treatment trial 3 (actt 3) to evaluate the safety and efficacy of a treatment regimen consisting of remdesivir plus interferon beta-1a for hospitalized adults who have a laboratory-confirmed sars-cov-2 infection with evidence of lung involvement, including a need for supplemental oxygen, abnormal chest x-rays, or illness requiring mechanical ventilation. veterinary uses in 2019, gs-441524 was shown to have promise for treating feline infectious peritonitis caused by a coronavirus. it has not been evaluated or approved by the us food and drug administration (fda) for the treatment of feline coronavirus or feline infectious peritonitis but has been available since 2019, through websites and social media as an unregulated black market substance. because gs-441524 is the main circulating metabolite of remdesivir and because gs-441524 has similar potency against sars-cov-2 in vitro, some researchers have argued for the direct administration of gs-441524 as a covid‑19 treatment.