Jynneos was administered intramuscularly instead of subcutaneously; The patient did not receive the scheduled second dose of Jynneos; Case reference number US-BN-2022-001807 is a spontaneous case report initially received on 08-Aug-2022 from a healthcare professional via Bavarian Nordic and concerns a 57-year-old male patient.  The patient's medical history included acquired immunodeficiency syndrome (AIDS), chronic obstructive pulmonary disease (COPD), and hepatitis C.  The patient's concomitant medication included doxycycline, diphenhydramine, B complex B12, Ensure (nutrients NOS), cholecalciferol, Albuterol (salbutamol sulfate), budesonide, Spiriva (tiotropium bromide), Biktarvy (bictegravir sodium, emtricitabine, tenofovir alafenamide fumarate), valganciclovir, dronabinol, and bupropion.  On 04-Aug-2022, the patient was vaccinated with the first dose of Jynneos (smallpox and monkeypox vaccine, live, nonreplicating; batch number: FDP00003), at a dose of 0.5 milliliters, administered intramuscularly (explicitly coded as 'inappropriate route of vaccination') in the right deltoid region, for immunization.  *As reported, the patient did not show up for the scheduled second dose of Jynneos* (explicitly coded as 'incomplete course of vaccination').  The patient did not experience any adverse events due to Jynneos vaccination.  Additional information received from Bavarian Nordic on 09-Aug-2022 included vaccine brand name confirmation.  All follow-up information is blended into the case narrative above, with the latest information presented between asterisks (*).  Follow-up information received from the other healthcare professional via Bavarian Nordic on 17-Aug-2022: New information included the patient's details, including medical history, vaccination details for Jynneos, and confirmation that the patient did not experience any adverse event.  Follow-up information received from the other healthcare professional via Bavarian Nordic on 02-Sep-2022: New information included concomitant medications, date and dosage of administered Jynneos, and confirmation that the patient at the time of the report did not receive any additional Jynneos doses.  Follow-up information received from the other healthcare professional via Bavarian Nordic on 09-Sep-2022: New information included confirmation that the patient did not show up for the scheduled vaccination which caused the non-event of missed dose to be replaced with the incomplete course of vaccination.; Reporter's Comments: A 57-year-old patient was vaccinated with Jynneos vaccine, administered intramuscularly in the right deltoid region (at a dose of 0.5 milliliters), which is considered as inappropriate route of vaccination, at un unknown dose for immunization. Reportedly,the patient did not show up for the scheduled second dose of Jynneos which is considered as incomplete course of vaccination. Incorrect route of product administration and incomplete course of vaccination are both considered listed per company convention. The patient did not experience any adverse event due to Jynneos vaccine. The patient's current medical condition included acquired immunodeficiency syndrome (AIDS), chronic obstructive pulmonary disease (COPD) and hepatitis C and concomitant medication included doxycycline, diphenhydramine, B complex B12, Ensure (nutrients NOS), cholecalciferol, Albuterol (salbutamol sulfate), budesonide, Spiriva (tiotropium bromide), Biktarvy (bictegravir sodium, emtricitabine, tenofovir alafenamide fumarate), valganciclovir, dronabinol, and bupropion. Causality for incorrect route of product administration and incomplete course of vaccination is assessed as not related to suspect product but to human factor. The case is non-serious.; Sender's Comments: A 57-year-old patient was vaccinated with Jynneos vaccine, administered intramuscularly in the right deltoid region (at a dose of 0.5 milliliters), which is considered as inappropriate route of vaccination, at un unknown dose for immunization. Reportedly,the patient did not show up for the scheduled second dose of Jynneos which is considered as incomplete course of vaccination. Incorrect route of product administration and incomplete course of vaccination are both considered listed per company convention. The patient did not experience any adverse event due to Jynneos vaccine. The patient's current medical condition included acquired immunodeficiency syndrome (AIDS), chronic obstructive pulmonary disease (COPD) and hepatitis C and concomitant medication included doxycycline, diphenhydramine, B complex B12, Ensure (nutrients NOS), cholecalciferol, Albuterol (salbutamol sulfate), budesonide, Spiriva (tiotropium bromide), Biktarvy (bictegravir sodium, emtricitabine, tenofovir alafenamide fumarate), valganciclovir, dronabinol, and bupropion. Causality for incorrect route of product administration and incomplete course of vaccination is assessed as not related to suspect product but to human factor. The case is non-serious.