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NCT Number: NCT07342829

Prospective Follow-up After MVA-BN Booster Vaccination

POQS-Boosted is a prospective observational study during which individuals who received Booster vaccination against mpox with the MVA-BN vaccine will be invited to provide biological samples at multiple times over the course of two years.

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Key information

Conditions

Monkeypox (Mpox) Animal Diseases DNA Virus Infections Infections Mpox, Monkeypox Poxviridae Infections Primate Diseases Rodent Diseases Virus Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Institute of Tropical Medicine

Antwerp, 2000, Belgium

About this study

Mpox caused a worldwide outbreak in 2022 and continues to circulate worldwide and causes sporadic cases in Belgium and elsewhere. In the last 10 days, the first cases infected with the probably more virulent clade Ib MPXV have been reported from men who have sex with men in Belgium, the Netherlands, and elsewhere, indicating circulating this viral clade in sexual networks. In Belgium, vaccination against mpox was ceased at the end of 2022 and evidence showed that antibody levels against MPXV have decreased since then, raising questions about sustained protectiveness and the potential for a new mpox outbreak to emerge.

POQS-Boosted is a prospective observational study during which individuals who received Booster vaccination against mpox with the MVA-BN vaccine will be invited to provide biological samples at multiple times over the course of two years.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Is scheduled to receive a booster dose of MVA-BN
  • ≥18 years
  • Willingness to provide written informed consent
  • Willingness to follow the study schedule

Exclusion criteria

  • Past or current MPXV infection

Treatment and study plan

Primary outcomes

  1. Orthopoxvirus-specific serum binding and neutralising antibody titre

    Time frame: from enrollment to the end of follow up at 2 years

    To describe the evolution of the orthopoxvirus-specific serum antibody response up to two years after MVA-BN booster vaccination

Secondary outcomes

  1. Orthopoxvirus-specific systemic T- and B cell-mediated immune responses to MPXV

    Time frame: from enrollment up to 2 years

    To describe the evolution of the orthopoxvirus-specific systemic cellular immune response up to two years after MVA-BN booster vaccination

  2. MPXV-specific IgA in saliva and anorectal samples; T and B cell-mediated immune responses to MPXV, measured on saliva and anorectal samples

    Time frame: from enrolment up to two years

    To describe the evolution of the orthopoxvirus-specific mucosal antibody & cellular immune response up to two years after MVA-BN booster vaccination

Study contacts

Contact information is provided by the study sponsor or research team.

Christophe Van Dijck, PhD

CONTACT

[email protected]

+32 3 345 58 65

Clinical Trials Unit Antwerp

CONTACT

[email protected]

+32 3 247 66 66

Sponsors and collaborators

Lead sponsor

Institute of Tropical Medicine, Belgium

Other

Registry information

Official study title

Prospective On-site Study for the Immunological Follow-up of Individuals Who Received Booster Vaccination With MVA-BN Against Mpox

Acronym: POQS-Boosted

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Jan 15, 2026
Registry last updated
Jan 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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