Smallpox Vaccine for Mpox Post-Exposure Prophylaxis: A Cluster RCT

ConditionMonkeypox
Trial statusRecruiting
Trial phasePhase 4
Trial typeInterventional
Biological sexAll
Age2+
SponsorMcMaster University

About this trial

A cluster randomized controlled trial to determine if smallpox vaccine reduces secondary cases and symptom severity in persons exposed to mpox.

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Household member of person with laboratory confirmed mpox

Age ≥ 2 years

Within 14 days of onset of illness in mpox index case

Disqualifiers

Pregnancy

Breastfeeding

Past serious allergic reaction to study vaccine components

Previous smallpox vaccination

Trial design

Design model

Parallel

Treatments tested in this trial

  • Bavarian Nordic smallpox vaccine

    Drug

    A single dose of the Bavarian Nordic smallpox vaccine will be given at baseline.

  • Typhoid VI Polysaccharide Vaccine Injectable Solution

    Drug

    A single dose of the typhoid vaccine will be given at baseline.

Treatment groups

3,000 Participants
are divided into 2 treatment groups
Group A: Smallpox vaccineExperimental treatment 1 intervention
Group B: Typhoid vaccineActive comparator 1 intervention

Trial outcomes

Primary outcomes

1

PCR-confirmed Mpox

To evaluate if smallpox vaccine vs control prevents RT-PCR confirmed mpox

Time frame
8 weeks
2

Symptom severity

To evaluate if smallpox vaccine vs control affects symptom severity

Time frame
8 weeks

Secondary outcomes

1

Resolution of skin lesions

To assess the time to resolution (i.e. a new skin layer has formed) of any skin lesion

Time frame
8 weeks
2

Number of skin lesions

To assess the number of skin lesions for any participants who develop mpox

Time frame
8 weeks
3

Self-reported Quality of Life

To assess the QOL of participants using the World Health Organization Quality of Life Scale

Time frame
8 weeks
4

Mpox complications

To assess longitudinal complications for any participants who develop mpox

Time frame
8 weeks

Other outcomes

1

Safety (SAEs, AESI)

Solicited SAE and AESIs will be followed at 4 months and 6 months

Time frame
6 months

Sponsors and contacts

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