Characterization of Vaccine-induced Responses Against Monkeypox (MoVIHvax) An Observational Prospective Cohort Study

Study Overview
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Brief Summary
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This observational study has been designed to characterize humoral and cellular immune responses after vaccination against monkeypox (MKP) in HIV positive and negative individuals at high risk of MKP infection during the vaccination campaign in the current monkeypox outbreak.

Detailed Description
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Of the 23,837 cases of monkeypox reported in the European Region of the WHO, 7.037 have been identified in Spain, according to the National Epidemiological Surveillance Network (RENAVE). Most of diagnosed individuals are men born in Spain, being nearly 40% HIV positive. The clinical evolution was satisfactory, although 3-7% of cases required hospitalization. Given the limited number of available doses of the MVA-BN vaccine, it has been recently approved its use as a single intradermal dose. However, this posology can be more reactogenic than subcutaneous injection and there is limited data on its immunogenicity and effectiveness in people living with HIV (PLWH), which account for about half of the monkeypox cases in the current outbreak. The present observational study has been designed to investigate the humoral and cellular immune responses following monkeypox vaccination in PLWH.

Official Title
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Characterization of Vaccine-induced Responses Against Monkeypox (MoVIHvax) An Observational Prospective Cohort Study

Conditions
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Monkeypox

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adult individuals of ≥18 years old. Willing to comply with the requirements of the protocol and available for follow-up for the planned duration of the trial. Has understood the information provided and capable of giving informed consent. Exclusion Criteria: 1. Participant has any medical condition and/or finding that in the investigator opinion might increase participant risks, interfere with the study or impair interpretation of study data.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| MKP vaccination for pre-exposure prophylaxis (HIV positive)<br>HIV positive individuals who receive MKP vaccination for pre-exposure prophylaxis | |
| MKP vaccination for pre-exposure prophylaxis (seronegative individuals)<br>HIV seronegative individuals who receive MKP vaccination for pre-exposure prophylaxis | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Proportion of participants with detectable anti-orthopox antibodies | Proportion of participants with detectable anti-orthopox antibodies at 29 - 90 days following first MVA-BN vaccination | Between day 29 - 90 | 
| Quantification of anti-orthopox antibodies | Quantification of anti-orthopox antibodies at 29 - 90 days following first MVA-BN vaccination | Between day 29 - 90 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes of the immunogenicity after the first vaccine dose | The geometric mean fold rise (GMFR) in anti-orthopox antibody titers from baseline to Day 29-90 and 150-180 after the first dose of MVA-BN and to 29-90 and 150-180 after the second dose (if applicable) | Between day 29 - 90 and between 150-180 (after the first dose) and between 29 - 90 and between 150-180 (after the second dose if applicable) | 
| To compare immunogenicity between HIV negative and HIV positive individuals | To compare the GMFR between HIV negative and HIV positive individuals | Between day 29 - 90 and between 150-180 (after the first dose) and between 29 - 90 and between 150-180 (after the second dose if applicable) | 
| Neutralization capacity of anti-orthopox antibodies | Neutralization titers measured as the reciprocal dilution inhibiting 50% of the infection (ID50) will be reported using a live virus assay (VNA) to measure cytopathic effect in Vero E6 cells after the first dose of MVA-BN. | Between day 29 - 90 and between 150-180 (after the first dose) and between 29 - 90 and between 150-180 (after the second dose if applicable) | 
| To compare neutralization capacity between HIV negative and HIV positive individuals | To compare ID50 between HIV negative and HIV positive individuals | Between day 29 - 90 and between 150-180 (after the first dose) and between 29 - 90 and between 150-180 (after the second dose if applicable) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Monkeypox vaccine, Immune responses, HIV