A Phase 1 interventional study of MVA strain monkeypox attenuated live vaccine (low dose) and MVA strain monkeypox attenuated live vaccine (high dose) in Monkeypox, sponsored by Shanghai Institute Of Biological Products. Recruiting at 1 site in China. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-10-03.
Sponsored by Shanghai Institute Of Biological Products · Phase 1, Interventional, and Prevention
This is a randomized, double blinded, controlled phase I clinical study. To evaluate the safety and immunogenicity of receiving two doses of MVA strain monkeypox attenuated live vaccine in individuals aged 18 years and above.
This is a randomized, double blinded, controlled phase I clinical study. The study plans to recruit 120 participants aged 18 years and above. The experimental vaccine MVA strain monkeypox attenuated live vaccine has two different doses (low dose and high dose). The ratio of low-dose experimental group, high-dose experimental group, and placebo group is 1:1:1. Participants will be divided into three groups: healthy individuals, men who have sex with men, and HIV infected individuals, with a ratio of 2:1:1. Different groups will be divided into individuals with a history of vaccination against smallpox and those without a history of immunization, based on whether each population has a history of vaccination against smallpox. Each participant will receive one dose of the experimental vaccine or placebo on day 0 and day 28, respectively.
Exclusion Criteria:
Participants without a history of immunization against smallpox
Biological: MVA strain monkeypox attenuated live vaccine (low dose)
Participants without a history of immunization against smallpox
Biological: MVA strain monkeypox attenuated live vaccine (high dose)
Participants with a history of immunization against smallpox
Biological: MVA strain monkeypox attenuated live vaccine (low dose)
Participants with a history of immunization against smallpox
Biological: MVA strain monkeypox attenuated live vaccine (high dose)
Participants without a history of immunization against smallpox
Other: Placebo
Participants with a history of immunization against smallpox
Other: Placebo
Low dose MVA strain monkeypox attenuated live vaccine
High dose MVA strain monkeypox attenuated live vaccine
Vaccine excipient
Immediate adverse events
The occurrence of any adverse events within 60 minutes after each dose of vaccine immunization.
Time frame: 60 minutes after each dose of vaccination
Solicited Adverse Events
Adverse events defined by the protocol that occurred to the participant during 0-14 days after each dose of vaccination.
Time frame: 14 days after each dose of vaccination
Unsolicited Adverse Events
Other adverse events that occurred among participants within 0-28/30 days after each vaccination, in addition to the solicited adverse events.
Time frame: 28 or 30 days after each dose of vaccination
Abnormal incidence rate of electrocardiogram
Abnormal electrocardiogram after 14 days of vaccination with each dose.
Time frame: 14 days after each dose of vaccination
Serious Adverse Events (SAE)
That is serious adverse events, any serious adverse events that occurred to the participant during the study period.
Time frame: 12 months after the last dose
Adverse Event of Special Interest (AESI)
Adverse events that require special attention as specified in the experimental protocol.
Time frame: 12 months after the last dose
Geometric Mean Titer (GMT) of neutralizing antibodies
GMI of neutralizing antibodies against monkeypox virus in the experimental vaccine groups and the placebo group.
Time frame: 14 days after the first dose of vaccine, before the second dose of vaccine and14 days, 28 days, 6 months, and 12 months after the second dose
Seroconversion rate of neutralizing antibodies
The neutralizing antibody seroconversion rate against monkeypox virus in the experimental vaccine groups and the placebo group.
Time frame: 14 days after the first dose of vaccine, before the second dose of vaccine and14 days, 28 days, 6 months, and 12 months after the second dose
Seropositive rate of neutralizing antibodies
The neutralizing antibody seropositive rate against monkeypox virus in the experimental vaccine groups and the placebo group.
Time frame: 14 days after the first dose of vaccine, before the second dose of vaccine and14 days, 28 days, 6 months, and 12 months after the second dose
GMT of binding antibody
GMI of binding antibody against monkeypox virus in the experimental vaccine groups and the placebo group.
Time frame: 14 days after the first dose of vaccine, before the second dose of vaccine and14 days, 28 days, 6 months, and 12 months after the second dose
Seroconversion rate of binding antibody
The binding antibody seroconversion rate against monkeypox virus in the experimental vaccine groups and the placebo group.
Time frame: 14 days after the first dose of vaccine, before the second dose of vaccine and14 days, 28 days, 6 months, and 12 months after the second dose
Seropositive rate of binding antibody
The binding antibody seropositive rate against monkeypox virus in the experimental vaccine groups and the placebo group.
Time frame: 14 days after the first dose of vaccine, before the second dose of vaccine and14 days, 28 days, 6 months, and 12 months after the second dose
Cellular immune level
Cellular immune levels of participants after receiving the experimental vaccine or placebo.
Time frame: 14 days after the first dose of vaccine, before the second dose of vaccine and14 days, 28 days after the second dose
Plan to share: No
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Shanghai Institute Of Biological Products