Идёт набор NCT06885853

Evaluation of Long-term Immunogenicity of a Boost Dose of MVA-BN Vaccine

— Наблюдательное Monkeypox

Ориентир для пациента и семьи

Простыми словами

Автоматическая сводка по структурированным данным реестра. Она помогает сориентироваться, но не заменяет официальный протокол или оценку врача.

Что изучают: Это наблюдательное исследование: исследуемое лечение участникам по протоколу не назначают.
Кому может быть актуально: Состояния в реестре: Monkeypox. Базовые параметры: от 18 лет · Все.
Что важно проверить: Возраст, диагноз и пол — только базовые ориентиры. Предыдущее лечение, анализы и другие обязательные условия указаны ниже в критериях участия.
Где проводится: Франция
Следующий шаг: Сохраните исследование, покажите его лечащему врачу и уточните актуальный статус у исследовательского центра. Расходы, документы и поездка →

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Обзор

This study is to evaluate the long-term immunogenicity of a boost dose of MVA-BN vaccine

Подробное описание

Mpox is an endemic zoonosis in Africa, caused by the MPXV virus of which there are two clades: I (former Congo Basin) and II (former West Africa). Since 2022, clade II has emerged globally via sexual transmission, primarily among men who have sex with men (MSM), resulting in a declaration of public health emergency (PHEIC) by the WHO.

In 2023, a clade I epidemic emerged in East Africa with a high case fatality rate (3-5%). In August 2024, the WHO again declared a PHEIC after the spread of clade I to African countries with no previously reported cases and outside Africa, raising fears of higher mortality and transmission.

A 3rd generation vaccine, MVA-BN (Imvanex® /Jynneos®), initially developed against smallpox, was approved in 2022 to prevent mpox. In France, the HAS recommends post- and pre-exposure vaccination for populations at risk: MSM, trans people with multiple partners, sex workers and certain professionals. For people born before 1980 (history of smallpox vaccination), a single dose is recommended as primary vaccination, while immunocompromised subjects require 3 doses.

Data show vaccine effectiveness of 20-80% in post-exposure prophylaxis (PEP) and \~80% in pre-exposure but neutralizing antibodies become undetectable after one year. Since the summer of 2024, the HAS has recommended a booster dose 2 years after the primary vaccination, on the basis of immunogenicity studies showing an increase in seroconversion to 98.7% one month after administration, but underlines the need to have other data, in particular on the durability of this response.

A study is proposed in MSM on HIV PrEP (pre-exposure prophylaxis), a priority population for structured medical monitoring, to evaluate the immunogenicity and safety of the MVA-BN booster in this context.

Первичные конечные точки

Immunogenicity a of a booster dose of MVA-BN vaccine [Срок оценки: 12 months]

Вторичные конечные точки (3)

Persistence of humoral immunogenicity [Срок оценки: 24 months]
Kinetics of the humoral response [Срок оценки: 24 months]
Description of cases of Mpox infection [Срок оценки: 24 months]

Критерии участия

Критерии включения

Men aged over 18 years
Have received two doses of MVA-BN vaccine as an initial schedule
Eligible for a booster dose of MVA-BN (according to the HAS recommendation)
Be eligible and wish to initiate PrEP-HIV treatment or be followed for PrEP-HIV treatment
Covered by social security (excluding AME)