The aim of the study is to investigate disease in volunteers deliberately infected with influenza A(H3N2), including biological markers of inflammation and immune response, and changes in physiological parameters including heart rate, respiratory rate, physical activity, oxygen saturation and electrocardiographic data during the onset of influenza infection. Ultimately, this may lead to prediction of symptomatic disease at an earlier stage to allow more effective interventions. The experimental medicine study design will involve human influenza infection challenge, whereby volunteers will be inoculated with influenza virus and monitored in hospital for 10 days as they develop and get better from flu. Continuously-monitoring wearable physiological sensors will be given to the participants 7 days before this and worn continuously until the end of the flu infection.

Influenza ('flu') is one of the most common causes of severe lung infection. Seasonal flu affects between 10 and 46% of the population each year and causes around 12 deaths in every 100,000 people infected. Furthermore, new strains of flu viruses emerge unpredictably every few years, causing pandemics that spread rapidly across the world. Since currently available antiviral drugs and vaccines cannot prevent these outbreaks, it is essential to be able to identify flu infections at an early stage to enable rapid treatment of individuals and implementation of public health measures.

The aim of the study is to investigate disease in volunteers deliberately infected with influenza A(H3N2), including biological markers of inflammation and immune response, and changes in physiological parameters including heart rate, respiratory rate, physical activity, oxygen saturation and electrocardiographic data during the onset of influenza infection. To achieve this, the investigators will recruit healthy volunteers and inoculate them with a flu virus, after which they will be observed in hospital while they develop a cold. Each volunteer will be given a number of devices that they will wear before and during infection. In addition, they will have blood and nasal samples taken to examine the way their immune system responds to infection. The resulting data will be analysed to see if the sensors data correlate with the onset of infection and these will be compared with measures of the immune response. Ultimately, the investigators anticipate that optimised sensor data from devices to be developed may be useful in rapidly detecting when someone is about to develop flu infection, so that they can quickly be treated and outbreaks may be identified at an early stage.

Inclusion Criteria:

• Healthy persons aged 18 to 55 years, able to give informed consent

Exclusion Criteria:

• Chronic respiratory disease (asthma, chronic obstructive pulmonary disease, rhinitis, sinusitis) in adulthood
• Inhaled bronchodilator or steroid use within the last 12 months
• Use of any medication or other product (prescription or over-the-counter) for symptoms of rhinitis or nasal congestion within the last 3 months
• Acute upper respiratory infection (URI or sinusitis) in the past 6 weeks
• Smoking in the past 6 months OR >5 pack-year lifetime history
• Subjects with allergic symptoms present at baseline
• Clinically relevant abnormality on chest X-ray
• Any ECG abnormality deemed clinically significant.
• Those in close domestic contact (i.e. sharing a household with, caring for, or daily face to face contact) with children under 3 years, the elderly (>65 years), immunosuppressed persons, or those with chronic respiratory disease
• Subjects with known or suspected immune deficiency
• Receipt of systemic glucocorticoids (in a dose ≥ 5 mg prednisone daily or equivalent) within one month, or any other cytotoxic or immunosuppressive drug within 6 months prior to challenge
• Known immunoglobulin A deficiency, immotile cilia syndrome, or Kartagener's syndrome
• History of frequent nose bleeds
• Any significant medical condition or prescribed drug deemed by the study doctor to make the participant unsuitable for the study
• Pregnant or breastfeeding women
• Positive urine drug screen
• Detectable baseline antibody titres against influenza challenge strains
• History of hypersensitivity to eggs, egg proteins, gentamicin, gelatin or arginine, or with life-threatening reactions to previous influenza vaccinations.
• Participants may only recruited if they have previously been involved in research if they have completed the earlier study and are beyond the washout period of any administered drugs or period of effect of any intervention that would cause interference for either study.

Data will be shared with Duke university, and RTI International, such as ethnicity and age. It will be identifiable only by their unique study code, with no personal details.

According to study protocol

Other than the 20 enrolled participants, there were some screening failures due to abnormal blood results, spirometry and chest x-ray.

Adverse event data was collected throughout the study period, until the 6 month follow-up visit.

Adverse event data was collected by observations and reports from study participants.

Lumee oxygen devices failed to charge on the charging stations provided. Advice and support were given by the engineering team but unable to resolve. No Lumee devices were used for participants SPFC011-SPFC016. The devices were shipped to manufacturer for further troubleshooting and investigation. The batteries were repaired, and the devices were returned to ICL for the remaining participants.