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Updated: Sep 8, 2025
An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection
Published on: December 10, 2013
Controlled Human Infection Challenge Studies with RSV
Pete Dayananda1, Christopher Chiu2, Peter Openshaw3
1Department of Infectious Disease, Imperial College London, London, UK.
Abstract:
Despite considerable momentum in the development of RSV vaccines and therapeutics, there remain substantial barriers to the development and licensing of effective agents, particularly in high-risk populations. The unique immunobiology of RSV and lack of clear protective immunological correlates has held back RSV vaccine development, which, therefore, depends on large and costly clinical trials to demonstrate efficacy. Studies involving the deliberate infection of human volunteers offer an intermediate step between pre-clinical and large-scale studies of natural infection. Human challenge has been used to demonstrate the potential efficacy of vaccines and antivirals while improving our understanding of the protective immunity against RSV infection. Early RSV human infection challenge studies determined the role of routes of administration and size of inoculum on the disease. However, inherent limitations, the use of highly attenuated/laboratory-adapted RSV strains and the continued evolutionary adaptation of RSV limits extrapolation of results to present-day vaccine testing. With advances in technology, it is now possible to perform more detailed investigations of human mucosal immunity against RSV in experimentally infected adults and, more recently, older adults to optimise the design of vaccines and novel therapies. These studies identified defects in RSV-induced humoral and CD8+ T cell immunity that may partly explain susceptibility to recurrent RSV infection. We discuss the insights from human infection challenge models, ethical and logistical considerations, potential benefits, and role in streamlining and accelerating novel antivirals and vaccines against RSV. Finally, we consider how human challenges might be extended to include relevant at-risk populations.
Insights
Human challenge studies accelerate respiratory syncytial virus (RSV) vaccine and antiviral development by mimicking natural infection. These models reveal immune defects, aiding the creation of effective RSV therapies, especially for high-risk groups.
Area of Science:
- Virology and Immunology
- Vaccinology
- Infectious Diseases
Background:
- Respiratory syncytial virus (RSV) poses significant health challenges, particularly in high-risk populations, with ongoing efforts to develop effective vaccines and therapeutics.
- Development of RSV vaccines is hindered by the virus's complex immunobiology and the absence of clear immunological correlates of protection, necessitating large, expensive clinical trials.
- Human challenge studies offer a controlled method to assess vaccine and antiviral efficacy and understand protective immunity against RSV, bridging preclinical research and large-scale trials.
Purpose of the Study:
- To evaluate the utility of human RSV infection challenge models in advancing the development of vaccines and therapeutics.
- To explore how these models can improve our understanding of RSV immunobiology and protective immunity.
- To discuss the ethical, logistical, and practical considerations for implementing human challenge studies, including in at-risk populations.
Main Methods:
- Review of historical and contemporary human RSV infection challenge studies.
- Analysis of insights gained from experimentally infected adult and older adult populations.
- Discussion of technological advancements enabling detailed investigation of mucosal immunity.
Main Results:
- Human challenge studies have demonstrated the potential efficacy of vaccines and antivirals against RSV.
- These models have identified defects in humoral and CD8+ T cell immunity, potentially explaining susceptibility to recurrent RSV infections.
- Advancements allow for more sophisticated investigations into mucosal immune responses.
Conclusions:
- Human RSV infection challenge models are valuable tools for streamlining and accelerating the development of novel RSV vaccines and antivirals.
- These studies provide critical insights into RSV immunobiology and host responses, informing therapeutic and vaccine design.
- Future applications may extend to include relevant at-risk populations, further optimizing agent development.
