Evaluate the Safety and Immunogenicity of the MVA-SIBP Vaccine in the Democratic Republic of the Congo

Inclusion Criteria: * Adults: 18 to 45 years inclusive at the time of informed consent. Adolescents: 12 to 17 years inclusive at the time of consent/assent. Children: 2 to 11 years inclusive at the time of consent/assent. * Participant is in good general health as determined by medical history, targeted physical examination, and clinical judgment of the investigator. * Adults: Able to read and understand the written informed consent, and willing to comply with all study procedures and availability for the entire study duration. Adolescents: Parent(s) or legally acceptable representative(s) able and willing to provide written informed consent; participant able and willing to provide appropriate assent per local regulations and IRB requirements. Children: Parent(s) or legally acceptable representative(s), with the relationship to the child similarly verified and documented on the consent form, and able and willing to provide written informed consent. * Willing and able to comply with all study procedures, visit schedule, and follow-up requirements as judged by the investigator. * No history of smallpox or mpox vaccination. No history of confirmed or suspected infection with monkeypox, cowpox, or vaccinia virus. * Negative serum or urine pregnancy test at screening and prior to each vaccination. Willing to use highly effective contraception from 30 days prior to first vaccination through 60 days after the last dose. Breastfeeding. * Resides in the study catchment area and has n…