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Vaccinia virus (VACV) is an orthopoxvirus used in smallpox vaccines, as a vector for novel cancer treatments, and for experimental vaccine research (1). The Advisory Committee on Immunization Practices (ACIP) recommends smallpox vaccination for laboratory workers who handle replication-competent VACV (1). For bioterrorism preparedness, the U.S. government stockpiles tecovirimat, the first Food and Drug Administration-approved antiviral for treatment of smallpox (caused by variola virus and globally eradicated in 1980*,†) (2). Tecovirimat has activity against other orthopoxviruses and can be administered under a CDC investigational new drug protocol. CDC was notified about an unvaccinated laboratory worker with a needlestick exposure to VACV, who developed a lesion on her left index finger. CDC and partners performed laboratory confirmation, contacted the study sponsor to identify the VACV strain, and provided oversight for the first case of laboratory-acquired VACV treated with tecovirimat plus intravenous vaccinia immunoglobulin (VIGIV). This investigation highlights 1) the misconception among laboratory workers about the virulence of VACV strains; 2) the importance of providing laboratorians with pathogen information and postexposure procedures; and 3) that although tecovirimat can be used to treat VACV infections, its therapeutic benefit remains unclear.

Background As of June 2, 2020, 67,113 cases and 321 deaths due to Coronavirus Disease 19 (COVID-19) have been reported in healthcare personnel (HCP) in the United States. Given the close contact of HCP with individuals with COVID-19, it is important to quantify the risk of acquiring COVID-19 in the healthcare setting. Methods We conducted a retrospective cohort study of HCP exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at our academic medical center from March 15, 2020 to May 16, 2020. Exposure during the study period was defined as having contact with patients or other HCP with COVID-19 within 6 feet of distance for at least 90 seconds when HCP’s eyes, nose, or mouth were not covered. HCP with exposures were monitored for symptoms consistent with COVID-19 for 14 days from last exposure and those who developed symptoms were tested for SARS-CoV-2 using RT-PCR. Results We identified 33 exposure events; 19 of which were patient-to-HCP exposures and 14 of which were HCP-to-HCP exposures. These 33 events resulted in 959 exposed HCP among whom 238 (25%) developed one or more symptoms of COVID-19 and required SARS-CoV-2 RT-PCR testing. Testing was performed at 7.1 ± 5.0 (mean ± SD) days from exposure. Of the 238 HCP who were tested, 82% were female and 49% were registered nurses (Table 1). Five HCP tested positive for SARS-CoV-2 by RT-PCR, but one was presumed to have acquired the disease from a household member with confirmed COVID-19. Among the four HCP who were infected due to occupational exposure, three were nurses while one was an environmental service worker (Table 1). Conclusion Despite exposures among HCP, the risk of acquiring symptomatic COVID-19 in the healthcare setting was low with less than 1% of HCP with occupational exposure subsequently diagnosed with COVID-19. With the definition of exposure now changed to at least 15 minutes of close contact without personal protective equipment, we anticipate fewer exposures at our healthcare facility and that much of COVID-19 transmission affecting HCP are due to community exposures. Disclosures All Authors: No reported disclosures

Healthcare organizations are required to provide workers with respiratory protection (RP) to mitigate hazardous airborne inhalation exposures. This study sought to better identify gaps that exist between RP guidance and clinical practice to understand issues that would benefit from additional research or clarification.

Background Vaccinia virus, a virus similar to but less virulent than variola virus, is a component of smallpox vaccines and increasingly used for medical research. Vaccinia immunoglobulin intravenous (VIGIV) and tecovirimat are stockpiled in the U.S. Strategic National Stockpile (SNS) for potential smallpox bioterror events, but only VIGIV is licensed for vaccinia treatment. On January 12, 2019, CDC was consulted for worsening infection in a laboratory worker after a needlestick with vaccinia. Methods We investigated demographic, clinical, vaccination, and exposure history and determined likelihood of vaccinia virus infection. Identity of the specific strain was sought because some have genetic modifications that might impact virulence. Discussions among stakeholders informed treatment decisions and facilitated medication access and usage. Swabs from the lesion were tested by real-time polymerase chain reaction for orthopoxvirus DNA, which includes vaccinia. Results The affected worker was an otherwise healthy 26-year-old woman who developed a pustular lesion at the needlestick site on her left index finger (Image). The patient had been injecting vaccinia virus into a mouse and had declined nationally recommended vaccination. Edema, lymphadenopathy, and fever raised concern for severe illness; neither the patient nor occupational health were certain of the vaccinia strain type. CDC, SNS, local health departments, drug manufacturers, and clinicians rapidly collaborated to make treatment decisions based on available information and ensure delivery of both biologics and administration of tecovirimat under an expanded access investigational new drug protocol. Eventually, a wound swab tested positive and the strain was determined to be one with no known impact on virulence. Conclusion With increasing use of vaccinia in research, occupational infections may continue to occur. Health clinics should extensively counsel staff who decline vaccination and have documentation on-hand about vaccinia virus types to inform treatment decisions. This response prompted CDC to develop outreach materials specifically for occupational vaccinia exposures. Disclosures All authors: No reported disclosures.