RPR was positive; Jynneos was given to the patient after it was stored in the refrigerator for more than eight weeks; Jynneos was given to the patient after it was stored in the refrigerator for more than eight weeks; First dose of Jynneos vaccine was administered to the patient intradermally; Second dose of Jynneos was administered to the patient 92 days after the first dose; Case reference number US-BN-2022-004870 is a spontaneous case report initially received on 09-Dec-2022 from a nurse and concerns a *35-year-old* male patient.  The patient's relevant medical history included asymptomatic HIV infection.   *The patient's concomitant medication included abacavir-dolutegravir-lamivud (as reported, brand name unknown).*  On 01-Sep-2022, the patient was vaccinated with the first dose of Jynneos (smallpox and monkeypox vaccine, live, nonreplicating; batch number: FDP00002) intradermally with 0.1 milliliters, at *right forearm* for the monkeypox/smallpox prophylaxis (explicitly coded as 'intradermal injection').   On 02-Dec-2022, 92 days after the first dose, the patient was vaccinated with the second dose of the Jynneos vaccine (smallpox and monkeypox vaccine, live, nonreplicating; batch number: FDP00005) subcutaneously with 0.5 milliliters, in the left upper arm. Administered dose was stored in the refrigerator longer than the recommended maximum of the eight-week period that ended on 29-Nov-2022 (explicitly coded as 'product storage error, product administration error', and 'inappropriate schedule of vaccine administered').    *On the same date, rapid plasma reagin (RPR) test was performed again and the result was positive. No mean platelet volume on file.*  *At the time of this report, the outcome of the event of 'syphilis' was unknown.*  *The reporter did not provide a seriousness of the event of 'syphilis', however, the event of 'syphilis' was assessed as serious due to medical significant criteria. Causality was not provided.*  Additional information received from Bavarian Nordic on 09-Dec-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 received on 28-Dec-2022 from a healthcare professional via Bavarian Nordic included: second dose vaccination details with mentioning of the different route of administration than once previously mentioned, patient details, medical history, and the information that the patient did not experience any adverse events.  Additional information received on 29-Dec-2022 from a healthcare professional via Bavarian Nordic included confirmation of the changed route and a changed date of the second dose administration and the first dose vaccination details which caused the addition of a non-event 'inappropriate schedule of vaccine administered'.  Follow-up received on 04-Jan-2022 from a healthcare professional: New information included patient's details, concomitant medication, anatomical location for the first administered Jynneos dose, and laboratory results. A new event 'syphilis' was added. The seriousness of the case was changed from non-serious to serious.; Reporter's Comments: A 35-year-old male patient was vaccinated with the first dose (0.1 ml) of Jynneos, intradermally (considered as intradermal injection) for the monkeypox/smallpox prophylaxis. 92 days after the first dose, the patient was vaccinated with the second dose of the Jynneos vaccine, subcutaneously (with 0.5 ml), in the left upper arm and the administered dose was stored in the refrigerator longer than the recommended maximum of the eight-week period, which is considered as product storage error, product administration error and inappropriate schedule of vaccine administered. Reportedly, on the day 0 after the second dose, rapid plasma reagin (RPR) test was performed and the result was positive (medical significance). Syphilis is unlisted for Jynneos according to the package insert. Product storage error, product administration error, inappropriate schedule of product administration and intradermal injection are all considered listed per company convention. The patient's relevant medical history included asymptomatic HIV infection and concomitant medication included abacavir-dolutegravir-lamivud. Considering the nature of the event, syphilis has been considered as not related to the suspect vaccine. Product storage error, product administration error, inappropriate schedule of product administration and intradermal injection are all assessed as not related to Jynneos vaccine, but to a human factor.; Sender's Comments: A 35-year-old male patient was vaccinated with the first dose (0.1 ml) of Jynneos, intradermally (considered as intradermal injection) for the monkeypox/smallpox prophylaxis. 92 days after the first dose, the patient was vaccinated with the second dose of the Jynneos vaccine, subcutaneously (with 0.5 ml), in the left upper arm and the administered dose was stored in the refrigerator longer than the recommended maximum of the eight-week period, which is considered as product storage error, product administration error and inappropriate schedule of vaccine administered. Reportedly, on the day 0 after the second dose, rapid plasma reagin (RPR) test was performed and the result was positive (medical significance). Syphilis is unlisted for Jynneos according to the packet insert. Product storage error, product administration error, inappropriate schedule of product administration and intradermal injection are all considered listed per company convention. The patient's relevant medical history included asymptomatic HIV infection and concomitant medication included abacavir-dolutegravir-lamivud. Considering the nature of the event, syphilis has been considered as not related to the suspect vaccine. Product storage error, product administration error, inappropriate schedule of product administration and intradermal injection are all assessed as not related to Jynneos vaccine, but to a human factor.