Experimental Human Rhinovirus Infection

The importance of the common cold derives primarily from its frequency and from its enormous socioeconomic impact. Human Rhinoviruses (HRVs) are the major cause of the common cold, being responsible for 30-50% of all acute respiratory illnesses with no causal remedies at hand. A model to investigate the pathophysiology of HRV infection and to test compounds that could treat or protect one from infection or developing symptoms would therefore be very valuable. With this HRV model it is also possible to investigate crosstalk between bacteria and viruses. This is very relevant because, following a viral infection, bacterial superinfections are common in clinical practice, and underlying mechanisms and subsequent possible therapies that could prevent this remain to be discovered. Worldwide, thousands of subjects have been exposed to experimental rhinovirus infection, of which more than 600 to HRV-16. Serious adverse events related to rhinovirus infection have never been documented. Therefore, this model can be considered a safe and highly reproducible model. Moreover, 52 volunteers have already been exposed to the HRV-16 virus from the batch that we want to use in this study.

Healthy volunteers who meet all inclusion criteria and none of the exclusion criteria that have given informed consent to participate in the study will be randomized to become either inoculated with HRV-16 (n=20; 10 male+10 female) or with placebo (saline 0.9%, n=20, 10 male+ 10 female). After one week a second inoculation with HRV-16 will be performed in both groups. In both groups, 50% of the subjects will be sero-negative and 50% sero-positive to HRV-16. One hundred TCID50 units of HRV-16 (by spraying 0.5 mL into each nostril in supine position in a randomized manner) will be administered.

The main study parameter is the rate of infection (defined by a positive viral culture, qPCR and/or a four-fold rise in antibody titre) caused by HRV-16 inoculation. Secondary endpoints include the duration of the incubation period, the effects of HRV-16 (re-)infection on cold symptoms and spirometry, kinetics of HRV-16-induced local inflammation parameters in nasal washes (including immune cells and cytokine production), kinetics of the HRV-16-induced systemic immune response (including circulating cytokines), the ability of HRV to modulate the systemic immune response (as reflected by the ex vivo production of inflammatory mediators by stimulated leukocytes), the effects of seropositivity on clinical and immunological responses, and the effects of HRV-16 infection on faecal and nasal-pharyngeal microbiota and host transcriptome and metabolome.