NCT07379580

A Randomized Clinical Trial Investigating the Safety, Reactogenicity, and Immunogenicity After Immunization With an mRNA-based Mpox Vaccine Candidate in Africa

Safety, Reactogenicity, and Immunogenicity of an Mpox mRNA Vaccine Candidate, BNT166a, in Healthy Participants Aged 18 Years and Older in African Countries: A Randomized, Double-blind, Placebo-controlled Phase II Trial

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 310 (estimated)
• Sponsor: BioNTech SE · Industry
• Sex: All
• Age: 18 Years – 64 Years
• Healthy volunteers: Accepted

Summary

This is a randomized, double-blind, placebo-controlled study which aims to assess the safety, reactogenicity, and immunogenicity after one and two doses of BNT166a or placebo in healthy participants.

Detailed description

This study will include the following cohorts: * Cohort 1: healthy adults aged 18 to 45 years inclusive who are Orthopoxvirus-naïve. * Cohort 2: healthy adults aged 18 to 64 years inclusive who are Orthopoxvirus-experienced. All participants will receive two doses of BNT166a or placebo at least 28 days apart. The planned study duration per participant is \~14 months.

Conditions

• Mpox (Monkeypox)
• Smallpox
• Orthopoxvirus Infection

Interventions

Type	Name	Description
BIOLOGICAL	BNT166a	Intramuscular injection. Injections should be given in the deltoid muscle, using the same non-dominant arm for all IMP doses.
OTHER	Placebo	Intramuscular injection. Injections should be given in the deltoid muscle, using the same non-dominant arm for all IMP doses.

Timeline

• Start date: 2026-02-20
• Primary completion: 2027-06-01
• Completion: 2027-06-01
• First posted: 2026-01-30
• Last updated: 2026-03-04

Locations

6 sites across 2 countries: Democratic Republic of the Congo, South Africa