couldn't go to work or sleep; The pain was so bad the patient could not lift arm up, go to work or sleep; Veins from injection site were turning black; Unbearable pain, felt like a constant wasp sting; The pain was so bad the patient could not lift arm up, go to work or sleep; It was moving five or six inches up arm and the spot it rock hard; The injection site was about the size of a golf ball; couldn't go to work or sleep; The pain of the vaccine was unbearable; Injection site started swelling the next day; The vaccine was administered under the skin with 1/5th the dose; Jynneos vaccine administered under the skin; Case reference number US-BN-2022-002185 is a spontaneous case report initially received on 31-Aug-2022 from consumer via Communication (reference number: USBAV22-1241) and concerns a male patient.  The patient's medical history included brown recluse bite, skin necrosis and motorcycle wreck.  The patient's historical drug included smallpox vaccine (brand name unknown) in 1961.  The patient's concomitant medication details were not provided.  On 28-Aug-2022, the patient was vaccinated with the first dose of Jynneos (smallpox and monkey-pox vaccine, live, nonreplicating; batch number: unknown) at a dose reported as 1/5th the dose (explicitly coded as 'vaccine underdose'), administered under the skin, for an unknown indication (explicitly coded as 'inappropriate route of vaccination').  On an unspecified date, also reported as 'the next day', the injection site started swelling.  On an unspecified date, the patient experienced unbearable pain, felt like a constant wasp sting, stating that he never went through any pain like that in his life. The patient had motorcycle wreck about 13 years ago and would equate the pain of the affected vaccine to twice that. The injection site was about the size of a golf ball and had black veins going from it. It was on the patient's fore-arm and veins were turning black. It was moving five to six inches up the patient's arm and the spot was rock hard.  On an unspecified date, the pain was so bad and that the patient could not go to work or sleep and could not lift his arm up. The patient received Lortab (loratadine) as a treatment, however it had no effect on these adverse events, as reported. The patient was using marijuana to reduce the pain.  At the time of this report, the outcome for the events of 'pain in arm', 'vein discoloration', 'wasp sting', 'impaired work ability', 'movements reduced', 'insomnia', 'injection site pain', 'injection site swelling', 'injection site induration' and 'injection site lump' was reported as not recovered/not re-solved.  The reporter did not provide seriousness assessment for these events. However, the event of 'pain in extremity' was assessed as serious due to medical significance, as the patient was unable to work or sleep and the event of 'impaired work ability' was assessed as serious due to seriousness criteria of disability. The reporter assessed all the events as possibly related to the product.   Additional information received on 01-Sep-2022 included local BN case ID.; Reporter's Comments: A male adult patient, experienced the non-serious event of injection site swelling on day 1 following vaccination with Jynneos (smallpox and monkeypox vaccine), administered under the skin at a 1/5th of the dose (which is considered inappropriate route of administration and vaccine underdose), for an unknown indication. The patient also experienced the serious events of impaired work ability (disability) and pain in arm (medically significant), as well as the non-serious events of vein discolouration, stinging (pain), hypokinesia, injection site induration, injection site mass, sleep disorder and injection site pain. Vein discoloration, stinging (pain) and impaired work ability are unlisted, whereas injection site induration, injection site pain and injection site swelling are listed per the Agency for Jynneos. Pain in extremity, hypokinesia, injection site lump and sleep disorder are unlisted per Agency. The patient's medical history included a smallpox vaccination in his childhood. No concomitant medication information was present. Considering the short latency of the symptoms constellation, as well as the known safety profile of the suspect vaccine, the events are considered related to Jynneos. Vaccine underdose and inappropriate route of vaccination are considered listed and not related per company convention. This case is considered a serious case due to disability and medically significant.; Sender's Comments: A male adult patient, experienced the non-serious event of injection site swelling on day 1 following vaccination with Jynneos (smallpox and monkeypox vaccine), administered under the skin at a 1/5th of the dose (which is considered inappropriate route of administration and vaccine underdose), for an unknown indication. The patient also experienced the serious events of impaired work ability (disability) and pain in arm (medically significant), as well as the non-serious events of vein discolouration, stinging (pain), hypokinesia, injection site induration, injection site mass, sleep disorder and injection site pain. Vein discoloration, stinging (pain) and impaired work ability are unlisted, whereas injection site induration, injection site pain and injection site swelling are listed per the Agency for Jynneos. Pain in extremity, hypokinesia, injection site lump and sleep disorder are unlisted per Agency. The patient's medical history included a smallpox vaccination in his childhood. No concomitant medication information was present. Considering the short latency of the symptoms constellation, as well as the known safety profile of the suspect vaccine, the events are considered related to Jynneos. Vaccine underdose and inappropriate route of vaccination are considered listed and not related per company convention. This case is considered a serious case due to disability and medically significant.