Patient received 0.1 mL of Jynneos vaccine under the skin - forearm; Patient received 0.1 mL of Jynneos vaccine under the skin - forearm; Injection site warmth; the site where the vaccine was injected (forearm) looked like a tinny pin prick and the next day like pimple with forehead with a bubbly center; Injection site redness; Injection site swelling; Injection site itching; Muscle aches; Case reference number US-BN-2022-002003 is a spontaneous case report initially received from a consumer via Communications (reference number: USBAV22-1109) on 22-Aug-2022 and concerns an adult male patient born in 1959.  The patient's medical history and concomitant medication details were not provided.  On 19-Aug-2022, the patient was vaccinated with the first dose of Jynneos (smallpox and monkeypox vaccine, live, nonreplicating, batch number FDP00013) at a dose of 0.1 mL intradermally for monkeypox prophylaxis (explicitly coded as underdose' and inappropriate route of vaccination'). On the same day, the site where the vaccine was injected (forearm) looked like a tinny pin prick, as reported.  On 20-Aug-2022, the patient's site where the vaccine was injected (forearm) looked like pimple with forehead with a bubbly center and the redness disappears from the middle to the outer site (it was 2 inch circle and swollen). On the same day, the patient experienced itching and slightly warm and muscle aches.  At the time of this report, the outcome for the events were not recovered/not resolved.  The reporter assessed the events as non-serious and possibly related to Jynneos.  Additional information received from on 22-Aug-2022 included local case ID.; Reporter's Comments: An adult male patient born in 1959 was vaccinated with the first dose of Jynneos, at a dose of 0.1 mL intradermally for monkeypox prophylaxis which is considered as underdose and inappropriate route of vaccination and on the same day, the site where the vaccine was injected (forearm) looked like a tinny pin prick. One day after he was vaccinated, the patient's injection site (forearm) looked like pimple with forehead with a bubbly center with redness which disappears from the middle to the outer site, itching, slightly warm and muscle aches. Injection site warmth and injection site mass are listed according to guidelines however unexpected according to guidelines for Jynneos. Injection site erythema, injection site swelling, injection site pruritus and myalgia are all listed and expected according to guidelines for Jynneos while underdose and incorrect route of product administration are both considered listed per company conventions. At this point,  the outcome was not resolved for all reported events. The patient's medical history and concomitant medication details were not provided. Causal relationship for injection site warmth, injection site mass, injection site erythema, injection site swelling, injection site pruritus and myalgia is assessed as related due to plausible temporal relationship, known product safety profile and since contributory role of the suspect product cannot be excluded. Underdose and  incorrect route of product administration are both assessed as not related to suspect product but to human factor. The case is non-serious.; Sender's Comments: An adult male patient born in 1959 was vaccinated with the first dose of Jynneos, at a dose of 0.1 mL intradermally for monkeypox prophylaxis which is considered as underdose and inappropriate route of vaccination and on the same day, the site where the vaccine was injected (forearm) looked like a tinny pin prick. One day after he was vaccinated, the patient's injection site (forearm) looked like pimple with forehead with a bubbly center with redness which disappears from the middle to the outer site, itching, slightly warm and muscle aches. Injection site warmth and injection site mass are listed according to guidelines however unexpected according to guidelines for Jynneos. Injection site erythema, injection site swelling, injection site pruritus and myalgia are all listed and expected according to guidelines for Jynneos while underdose and incorrect route of product administration are both considered listed per company conventions. At this point,  the outcome was not resolved for all reported events. The patient's medical history and concomitant medication details were not provided. Causal relationship for injection site warmth, injection site mass, injection site erythema, injection site swelling, injection site pruritus and myalgia is assessed as related due to plausible temporal relationship, known product safety profile and since contributory role of the suspect product cannot be excluded. Underdose and  incorrect route of product administration are both assessed as not related to suspect product but to human factor. The case is non-serious.