An observational study in Monkeypox, sponsored by Fundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia. Recruiting at 3 sites in Spain. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-07-07.
Sponsored by Fundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia · Observational
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.
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.
72 studies on the registry are indexed under Mpox, Monkeypox; 30 are open to participants now.
This study's planned enrollment of 100 is below the median of 224 across 34 observational studies indexed under Mpox, Monkeypox.
Browse Mpox, Monkeypox studies →Fundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia is the lead sponsor of 45 studies on the registry; 4 are open to participants now.
Counted across the registry records on this site, refreshed daily.
100 individuals who have been/will be vaccinated against MKP as pre-exposuire profilaxis following the National Vaccination Plan (40-50/50-60% of HIV negative and HIV positive individuals)
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:
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.
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.
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.
HIV positive individuals who receive MKP vaccination for pre-exposure prophylaxis
HIV seronegative individuals who receive MKP vaccination for pre-exposure prophylaxis
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
Time frame: Between day 29 - 90
Quantification of anti-orthopox antibodies
Quantification of anti-orthopox antibodies at 29 - 90 days following first MVA-BN vaccination
Time frame: Between day 29 - 90
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)
Time frame: 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
Time frame: 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.
Time frame: 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
Time frame: 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)
Ran from Sep 2022 to primary completion in Jul 2026, 45 months.
Of 23 observational studies under Mpox, Monkeypox, half reached primary completion within 18 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 45. This study's 45 months is above that.
How these figures are worked out, and which studies are left out of them.
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Fundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia