Exploring Monkeypox: prospects for therapeutics through computational-aided drug discovery

Background Cases of human monkeypox are rarely seen outside of west and central Africa. There are few data regarding viral kinetics or the duration of viral shedding and no licensed treatments. Two oral drugs, brincidofovir and tecovirimat, have been approved for treatment of smallpox and have demonstrated efficacy against monkeypox in animals. Our aim was to describe the longitudinal clinical course of monkeypox in a high-income setting, coupled with viral dynamics, and any adverse events related to novel antiviral therapies. Methods In this retrospective observational study, we report the clinical features, longitudinal virological findings, and response to off-label antivirals in seven patients with monkeypox who were diagnosed in the UK between 2018 and 2021, identified through retrospective case-note review. This study included all patients who were managed in dedicated high consequence infectious diseases (HCID) centres in Liverpool, London, and Newcastle, coordinated via a national HCID network. Findings We reviewed all cases since the inception of the HCID (airborne) network between Aug 15, 2018, and Sept 10, 2021, identifying seven patients. Of the seven patients, four were men and three were women. Three acquired monkeypox in the UK: one patient was a health-care worker who acquired the virus nosocomially, and one patient who acquired the virus abroad transmitted it to an adult and child within their household cluster. Notable disease features included viraemia, prolonged monkeypox virus DNA detection in upper respiratory tract swabs, reactive low mood, and one patient had a monkeypox virus PCR-positive deep tissue abscess. Five patients spent more than 3 weeks (range 22–39 days) in isolation due to prolonged PCR positivity. Three patients were treated with brincidofovir (200 mg once a week orally), all of whom developed elevated liver enzymes resulting in cessation of therapy. One patient was treated with tecovirimat (600 mg twice daily for 2 weeks orally), experienced no adverse effects, and had a shorter duration of viral shedding and illness (10 days hospitalisation) compared with the other six patients. One patient experienced a mild relapse 6 weeks after hospital discharge. Interpretation Human monkeypox poses unique challenges, even to well resourced health-care systems with HCID networks. Prolonged upper respiratory tract viral DNA shedding after skin lesion resolution challenged current infection prevention and control guidance. There is an urgent need for prospective studies of antivirals for this disease. Funding None.

Human monkeypox is a zoonotic orthopoxvirus with presentation similar to smallpox. Monkeypox is transmitted incidentally to humans when they encounter infected animals. Reports have shown that the virus can also be transmitted through direct contact (sexual or skin-to-skin), respiratory droplets, and via fomites such as towels and bedding. Multiple medical countermeasures are stockpiled for orthopoxviruses such as monkeypox. Two vaccines are currently available, JYNNEOS TM (live, replication incompetent vaccinia virus) and ACAM2000 ® (live, replication competent vaccinia virus). While most cases of monkeypox will have mild and self-limited disease, with supportive care being typically sufficient, antivirals (e.g. tecovirimat, brincidofovir, cidofovir) and vaccinia immune globulin intravenous (VIGIV) are available as treatments. Antivirals can be considered in severe disease, immunocompromised patients, pediatrics, pregnant and breastfeeding women, complicated lesions, and when lesions appear near the mouth, eyes, and genitals. The purpose of this short review is to describe each of these countermeasures.

In April 2003, an outbreak of monkeypox occurred in the United States following the importation of monkeypox virus (MPXV)-infected animals in a consignment of exotic pets from West Africa. Transmission of the virus to non-African captive species, including prairie dogs, preceded human disease. We evaluated the influence of the route of infection on clinical illness for persons with confirmed and probable cases of human monkeypox. Exposures were categorized as being "noninvasive" (e.g., the person touched an infected animal, cleaned an infected animal's cage, and/or stood within 6 feet of an infected animal) or "complex" (e.g., invasive bite or scratch from an ill prairie dog plus potential noninvasive exposure), and associations between exposure, illness manifestation, and illness progression (i.e., elapsed time from first exposure to an ill prairie dog through various benchmarks of illness) were assessed. Patients with complex exposures were more likely than patients with noninvasive exposures to have experienced pronounced signs of systemic illness (49.1% vs. 16.7%; P=.041) and to have been hospitalized during illness (68.8% vs. 10.3%; P<.001). Complex exposures were also associated with shorter incubation periods (9 days for complex exposures vs. 13 days for noninvasive exposures) and the absence of a distinct febrile prodrome. The findings of this study indicate that route of infection can influence monkeypox illness manifestations.