Contact transmission of vaccinia; secondary transmission from mother to child; This case was obtained from a scientific literature titled "Contact transmission of vaccinia to an infant diagnosed by viral culture and metagenomic sequencing", on date 11MAR2021.   Literature citation: Contact transmission of vaccinia to an infant diagnosed by viral culture and metagenomic sequencing. Open Forum Infect Dis. 2020.   A 10-month-old female infant who had "contact transmission of vaccinia; sores on the baby's hands and mouth were a result of autoinoculation" (PT: Vaccinia virus infection) following Vaccinia transmission was suspected with ACAM2000 (smallpox vaccine, live). It was reported that an "occult transmission from a recent vaccine to the mother, and then from mother to child, to be the most likely etiology of the child's skin lesions in this case" (PT: Secondary transmission).    Case report: It was reported that she was presented to a hospital for evaluation of fever and new skin lesions. On exam, the diaper area had 10 circular to irregularly shaped ulcers, 1-2.5 cm in size, with undermined borders, all painful to touch. The parents reported "blisters" that developed 4-5 days prior and ulcerated in the following days. Scattered red macules were noted in perioral and acral locations.   The patient had received no medical care before this illness, and she was behind in her vaccines, not travel and no animal exposure or recent changes in topical hygiene products. The patient improved with supportive care. Vaccinia immune globulin and antivirals with anti-vaccinia activity were considered for treatment of the skin lesions but ultimately were not administered.   The patient's mother had a history of moderate to severe atopic dermatitis and reported a recent illness and flare of her skin disease. On exam, she had numerous circular collarettes of scale over her forearms and arms from a vesicular eruption that began the week prior but was resolving without intervention. The patient's father, an active-duty military member, had a 1-cm vesicular, crusted plaque above his right upper lip, which he attributed to a cold sore. Neither parent, nor other close contacts, had received recent live-virus vaccinations.    At the time of this report, the child's parents had not undergone testing for vaccinia exposure, and a follow-up epidemiologic investigation failed to identify another potential source of exposure. As neither parent had been recently vaccinated, the author considered occult transmission from a recent vaccinee to the mother, and then from mother to child, to be the most likely etiology of the child's skin lesions in this case. Given the distribution of the child's lesions, it was suspected that transmission occurred during diaper care and that the sores on the baby's hands and mouth were a result of autoinoculation.   The author commented that ACAM2000 contains replication-competent virus that can be shed from the intradermal vaccination site for up to 3 weeks, and this vaccine was in use during the time this patient developed infection. As many military members in the father's workplace receive ACAM2000 vaccine, it was theoretically possible that contact transmission resulted in unrecognized secondary vaccinia infection in the father, with or without tertiary infection in the mother, subsequently followed by infection in this infant. Secondary transmission to the child through fomites in the household is also possible, although less likely based on the location of the lesions and given a lack of identifiable family contact with known recent vaccinees.   Based on the available information in the article, 3 individual case safety reports 21000032LT (infant) 21000033LT (mother) and 21000034LT (father) were created and cross linked in the database.  Company Comment: The company agrees with the author that there was a secondary and tertiary transmission from the mother to the baby. ACAM2000 is a live virus vaccine and has a potential to cause vaccinia infection to household members and close contacts by accidental (contact) inoculation, and the causality of vaccinia virus infection and secondary transmission is assessed as possible. The case does not meet the seriousness criteria but will be submitted to the FDA as required.; Sender's Comments: The company agrees with the author that there was a secondary and tertiary transmission from the mother to the baby. ACAM2000 is a live virus vaccine and has a potential to cause vaccinia infection to household members and close contacts by accidental (contact) inoculation, and the causality of vaccinia virus infection and secondary transmission is assessed as possible. The case does not meet the seriousness criteria but will be submitted to the FDA as required.