Break-through Infection Following Mpox vaccinatIon

Completed

• Conditions: Mpox
• Interventions: Drug: Mpox Vaccine

• Registration Number: NCT05522296
• Lead Sponsor: Fundación FLS de Lucha Contra el Sida, las Enfermedades Infecciosas y la Promoción de la Salud y la Ciencia

Brief Summary

The purpose of this study is to assess the protection of smallpox preexposure vaccination against infection with mpox in real-world individuals with risk factors for mpox.

Detailed Description

A Target Trial Emulation study that tries to emulate the sequential specification of a target trial will be conducted measuring and controlling confounders when there is a common cause of vaccination and outcome event.

Participants will be provided with a Quick response (QR) code to access the RedCap study platform, which will guide them to the enrolment process. If the participant accepts and meets all the inclusion and none of the exclusion criteria, they will be directed to a baseline survey to self-collect sociodemographic data and information regarding risk factors, sexual behaviour, vaccination, and exposure to mpox.

Newly vaccinated participants will be matched 1:1 to unvaccinated controls. The matching will be performed based on the site of recruitment, and self-reported baseline sexual health and practices. Vaccinated and unvaccinated participants will be matched on variables associated with the probability of infection.

Follow-up will include regular surveys every month from the index date (i.e., enrolment date in the unvaccinated group, or vaccination date for the vaccinated group), to collect data on change on risk factors, sexual behaviour in the past month, vaccination status, and exposure to mpox. The participant will be asked to self-report if they develop symptoms suggestive of mpox, and the study platform will direct them to a specific mpox infection survey.

For each participant, follow-up will end at the earliest of the following events: mpox infection, voluntary withdraw, or the end of the study period. A health record review will be conducted to corroborate the diagnosis of new cases and to provide validity to the self-report.

Study Timeline

• Study First Submitted: 2022-08-27
• Study First Submitted QC: 2022-08-27
• Study First Posted: 2022-08-31
• Study Start: 2022-09-12
• Primary Completion: 2024-03-30
• Study Completion: 2024-03-30
• Status Verified: 2024-06
• Last Update Submitted: 2024-06-05
• Last Update Posted: 2024-06-06

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 3125

Inclusion Criteria

1. Individuals aged 18 years or older.

2. Individuals with general risk factors for mpox infection, as currently defined by the local guidelines for vaccination. These risk factors include at least one of the following items:

   • Individual-reported use of HIV pre-exposure prophylaxis (PrEP).
   • Individual-reported chemsex practices
   • Individual-reported multiple sexual partners.
   • Individuals with a history of a sexually transmitted infection (STI) in the past year.
   • Individuals living with HIV infection.

3. Signature of informed consent.

Exclusion Criteria

1. Unable to provide signature of informed consent.
2. Past infection with monkeypox.
3. Past smallpox vaccination.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
Vaccinated	Mpox Vaccine	Vaccinated individuals with smallpox and mpox vaccine (Live Modified Vaccinia Virus Ankara) who have risk factors for monkeypox infection and do not have a past history of mpox infection.

Primary Outcome Measures

Name	Time	Method
Polymerase chain reaction (PCR)-confirmed mpox infection	From 14 days after the index date to twelve months after the index date	Mpox PCR positivity in participants with mpox infection symptoms

Secondary Outcome Measures

Name	Time	Method
Duration of general symptoms	From 14 days after the index date to twelve months after the index date	Time from onset to resolution of general symptoms in participants with PCR-confirmed mpox infection (in days).
Medical treatment	From 14 days after the index date to twelve months after the index date	Requirement of medical treatment (yes/no)
Hospitalization	From 14 days after the index date to twelve months after the index date	Requirement of hospital admission (yes/no)
Polymerase chain reaction (PCR)-confirmed mpox infection	From immediately after the index date to twelve months after the index date	Mpox PCR positivity in participants with mpox infection symptoms
Severity of rash	From 14 days after the index date to twelve months after the index date	Number of mpox lesions (lesions count)
Duration of skin rash	From 14 days after the index date to twelve months after the index date	Time from onset to resolution of skin rash in participants with PCR-confirmed
Scarring	From 14 days after the index date to twelve months after the index date	Residual scarring after mpox (yes/no)
Safety and tolerability	One month after vaccination	Description of systemic and skin reactions

Trial Locations

Locations (6)

Hospital Regional III Honorio Delgado; 🇵🇪 Arequipa, Peru

Germans Trias i Pujol Hospital; 🇪🇸 Badalona, Barcelona, Spain

Hospital Clínico San Borja Arriarán; 🇨🇱 Santiago de Chile, Región Metropolitana, Chile

Instituto Conmemorativo Gorgas de Estudios de la Salud (ICGES); 🇵🇦 Panamá, Panama

Hospital Nacional Arzobispo Loayza; 🇵🇪 Lima, Peru

Hospital Regional Docente de Trujillo; 🇵🇪 Trujillo, Peru