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 (part of Sinopharm) · 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.
72 studies on the registry are indexed under Mpox, Monkeypox; 30 are open to participants now.
This study's planned enrollment of 120 is below the median of 305 across 36 interventional studies indexed under Mpox, Monkeypox.
Browse Mpox, Monkeypox studies →Shanghai Institute Of Biological Products is the lead sponsor of 34 studies on the registry; 14 are open to participants now.
First submitted after Shanghai Institute Of Biological Products became part of Sinopharm.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Live vaccines
Vaccines made with a weakened form of the germ, such as measles–mumps–rubella (MMR), chickenpox and yellow fever. They can be risky when the immune system is weakened. Flu injections are not live; the nasal flu spray is.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ECG (electrocardiogram)
A recording of the heart’s electrical activity, taken with stickers on the chest, arms and legs. It takes a few minutes and does not hurt.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis C tests
Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.
After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
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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