Human challenge models for vaccine development—strengths, limitations, and expansion into endemic settings: a HIC-Vac meeting report

TL;DR

This report discusses the use of human infection challenge studies for vaccine development, emphasizing their expansion into low- and middle-income countries to better address global health needs.

Contribution

The paper emphasizes the need to expand human challenge studies into endemic settings to improve vaccine relevance for LMIC populations.

Findings

HIC studies should not be restricted to high-income settings to ensure relevance for LMIC populations.

Immune responses and vaccine efficacy vary across different settings and populations.

The report highlights current and future challenge models, including ethical and industry considerations.

Abstract

The HIC-Vac network is a unique association of researchers focussed on the development and use of human infection challenge (HIC, otherwise known as controlled human infection models or CHIM) studies for vaccine and therapeutic development, particularly for pathogens of high global impact. The fifth annual meeting of the HIC-Vac network was held on 1–3 November 2023. The theme of the meeting was capacity-building in endemic settings particularly in low- and middle-income countries (LMIC), where pathogens cause the greatest morbidity and mortality. In this report we highlight the strengths and limitations of HIC and expansion of such studies into endemic settings, noting that immune responses and vaccine efficacy differ across diverse settings and populations. The consensus was that HIC studies must not be restricted to high income settings if they are to be relevant to LMIC populations. This report summarizes the work presented at the HIC-Vac annual meeting, highlighting current and future challenge models, challenge agent manufacture, public engagement, ethics, and industry perspectives.

Graphical Abstract

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