The patient was vaccinated with Jynneos intramuscularly instead of subcutaneous; The patient experienced tightness, firmness and muscle pain on the same day as vaccinated with Jynneos; The patient experienced tightness, firmness and muscle pain on the same day as vaccinated with Jynneos; Case reference number US-BN-2022-001791 is a spontaneous case report initially received on 05-Aug-2022 from a consumer and concerns 42-year-old male patient.  *The patient had no medical history and was not taking any concomitant medications.*  On 28-Jul-2022, the patient was vaccinated with Jynneos vaccine (Smallpox and Monkeypox Vaccine, Live, Nonreplicating; batch number: unknown) administered intramuscularly in the left arm (explicitly coded as 'Inappropriate route of vaccination') at an unknown dose.  On the same day, the patient experienced, as reported, tightness, firmness, and muscle pain.  *The reporter assessed events as possibly related and non-serious.*   *On 20-Aug-2022, the patient recovered from events of tightness, firmness and muscle pain.*  Additional information received from Bavarian Nordic on 08-Aug-2022 included local case ID.  All follow-up information is blended into the case narrative above, with the latest information presented between asterisks (*).  Follow up information was received from the reporter on 02-Sep-2022:  New information included confirmation of medical history and concomitant medications, seriousness and causality assessment and date the patient recovered from events.; Reporter's Comments: A 42-year-old male patient experienced tightness, firmness and muscle pain, on the same day he was vaccinated with Jynneos vaccine, administered intramuscularly in the left arm which is considered as inappropriate route of vaccination. Muscle tightness is considered listed according to insert for Jynneos however unexpected per insert while myalgia is both listed and expected. Incorrect route of product administration is considered listed per company convention. The patient outcome was resolved for muscle tightness and myalgia. The patient had no medical history and was not taking any concomitant medications. Causality is assessed as related for muscle tightness and myalgia due to plausible temporal relationship, known product safety profile and since contributory role of the suspect product cannot be excluded while incorrect route of product administration is assessed as not related to suspect product but to human factor. The case is non-serious.; Sender's Comments: A 42-year-old male patient experienced tightness, firmness and muscle pain, on the same day he was vaccinated with Jynneos vaccine, administered intramuscularly in the left arm which is considered as inappropriate route of vaccination. Muscle tightness is considered listed according to insert for Jynneos however unexpected per insert while myalgia is both listed and expected. Incorrect route of product administration is considered listed per company. The patient outcome was resolved for muscle tightness and myalgia. The patient had no medical history and was not taking any concomitant medications. Causality is assessed as related for muscle tightness and myalgia due to plausible temporal relationship, known product safety profile and since contributory role of the suspect product cannot be excluded while incorrect route of product administration is assessed as not related to suspect product but to human factor. The case is non-serious.