Might have had an allergic reaction; The patient supposed to have the second Jynneos dose but postponed until further information; The vaccine administered at the third layer of the skin; Rash inside mouth, on the roof of the mouth, painful and bleeding; Rash inside mouth, on the roof of the mouth, painful and bleeding; Rash inside mouth, on the roof of the mouth, painful and bleeding; Lump behind arm: black and blue, hard and raised; Lump behind arm: black and blue, hard and raised; Lump behind arm: black and blue, hard and raised; Itching; Case reference number US-BN-2022-002187 is a spontaneous case report initially received on 31-Aug-2022 from a consumer via Communication (reference number: USBAV22-1244) and concerns a 26-year-old male patient.  The patient's medical history and concomitant medication details were not provided.  On 29-Jul-2022, the patient was vaccinated with the first dose of Jynneos (Smallpox and Monkeypox Vaccine, Live, Nonreplicating; batch number unknown), at an unknown dose, in the third layer of the skin behind the patient's left arm, for monkeypox prophylaxis (explicitly coded as 'Inappropriate route of vaccination'). On the same day, the patient experienced itching and a lump behind the arm which was black and blue, hard, and raised.  On 14-Aug-2022, 16 days after Jynneos vaccination, the patient experienced a rash inside the mouth, on the roof of the mouth which was painful and bleeding and it was the most concerning symptom to the patient. As reported, the patient took home remedies (unspecified), some water, and Tylenol (paracetamol).  On an unspecified date in 2022, reported as three weeks after the onset date (29-Jul-2022), the patient recovered from the events of 'itching' and 'lump behind arm: black and blue, hard and raised'.  On an unspecified date in 2022, reported as one week after the onset date (14-Aug-2022), the patient recovered from the event of 'rash inside the mouth, on the roof of the mouth, painful and bleeding'.  On an unspecified date, the patient might have had an allergic reaction. As reported, the patient was supposed to have the second Jynneos dose at the time of this report, reported as today, but it was postponed until further information (explicitly coded as 'missed dose'). It was stated that allergic reactions could go to the airway. As reported, no treatment was given due to adverse events, and no laboratory tests were performed. *The patient planned to have an allergic test to Jynneos vaccine ingredients.*  At the time of this report, the outcome of the event of ''allergic reaction'' was unknown.  The reporter assessed the events of 'rash mouth', 'rash haemorrhagic', 'mouth pain', 'injection site lump', 'injection site coloration', 'injection site induration', 'itching', and 'allergic reaction' as non-serious and possibly related to Jynneos vaccine.  Additional information received on 01-Sep-2022 from 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 received from a consumer via Communication on 01-Sep-2022 included the reporter's email address and question about  Jynneos vaccine ingredients because of the allergic test patient was planning to have.; Reporter's Comments: A 26-year-old male patient experienced the non-serious events of injection site lump, injection site discolouration, injection site induration and pruritus on day 0, following first vaccination of Jynneos, at an unknown dose for monkeypox prophylaxis, applied in the third layer of the skin behind the patient's left arm (which is considered an inappropriate route of vaccination). On day 16, the patient experienced the non-serious event of painful and bleeding oral rash. It was thought that the patient had possibly experienced an allergic reaction. Therefore, the second vaccination was postponed (which is considered product dose omission). The events of oral rash, bleeding rash and mouth pain are unlisted per guidelines for Jynneos. The events of injection site lump and injection site discolouration are listed per guidelines for Jynneos. The events of injection site induration, pruritus and allergic reaction are listed per guidelines for Jynneos. The events of product dose omission issue and incorrect route of product administration are considered listed per company convention. The patient's relevant medical history and concomitant medications were not reported. Considering their short latency, as well as the known safety profile, the events of injection site lump, induration, discolouration and pruritus are considered related to Jynneos. With the limited information available, a causal relationship between Jynneos and the events of painful and bleeding oral rash and possible allergic reaction cannot be ruled out, and events are assessed as related to Jynneos. Product dose omission issue and incorrect route of product administration are not related to the suspect product, but to human factor.; Sender's Comments: A 26-year-old male patient experienced the non-serious events of injection site lump, injection site discolouration, injection site induration and pruritus on day 0, following first vaccination of Jynneos, at an unknown dose for monkeypox prophylaxis, applied in the third layer of the skin behind the patient's left arm (which is considered an inappropriate route of vaccination). On day 16, the patient experienced the non-serious event of painful and bleeding oral rash. It was thought that the patient had possibly experienced an allergic reaction. Therefore, the second vaccination was postponed (which is considered product dose omission). The events of oral rash, bleeding rash and mouth pain are unlisted per guidelines for Jynneos. The events of injection site lump and injection site discolouration are listed per guidelines but unlisted per guidelines for Jynneos. The events of injection site induration, pruritus and allergic reaction are listed per guidelines for Jynneos. The events of product dose omission issue and incorrect route of product administration are considered listed per company convention. The patient's relevant medical history and concomitant medications were not reported. Considering their short latency, as well as the known safety profile, the events of injection site lump, induration, discolouration and pruritus are considered related to Jynneos. With the limited information available, a causal relationship between Jynneos and the events of painful and bleeding oral rash and possible allergic reaction cannot be ruled out, and events are assessed as related to Jynneos. Product dose omission issue and incorrect route of product administration are not related to the suspect product, but to human factor.