Flu and Mood in Older Adults

Infectious diseases are important causes of morbidity and mortality worldwide, and vaccinations are vital to reducing the risk of disease. Vaccine efficacy, however, is dependent on the immune system's ability to respond to vaccination antigens. Influenza vaccines play an important role in combating influenza. However, some populations, such as older adults, respond poorly to vaccination due to their compromised immune systems, with efficacy at 17-53% (compared to 70-90% in young adults).

Behavioural and psychological influences have been shown to alter immune responses. An observational study looking into behavioural and psychological effects, which have been identified as immune modulators (stress, physical activity, nutrition, mood and sleep) found greater positive mood on the day of vaccination predicted significantly greater antibody responses to influenza vaccination. Following this, a feasibility study carried out on 110 older adults demonstrated the ability to enhance positive mood prior to influenza vaccination using a brief digital intervention.

The clinical trial will be the next phase of this research, where the cohort will consist of 650 participants, aged over 65 years, who will receive the quadrivalent, cell-grown influenza vaccination, immediately after one of three conditions. These conditions include: the control arm of usual participant care for vaccination; participants watching a 15-minute digital intervention via a tablet that does not allow content selection; and a personalised digital intervention that allows for participant selection of content they would like to view for 15 minutes. The purpose of these digital interventions is to enhance positive mood of patients prior to vaccination.

The primary aim of this trial is to explore which of two brief interventions has the largest effect on positive mood, compared with usual care. The secondary aim is to measure vaccine specific antibody responses, with the hypothesis that individuals with enhanced positive mood will present larger vaccine specific antibody responses.

This trial will also allow data collection on exploring recruitment, attrition, intervention engagement, and practicality of collecting clinical data available through electronic records and self-report measures to inform the design of a future definitive trial.

Inclusion criteria

• Males and Females aged 65-85 years (inclusive)
• Received influenza vaccination for the 2018/19 season
• Eligible to receive 2019/20 influenza vaccination as part of usual care
• Ability to give informed consent

Exclusion criteria

• Males and Females aged less than 65 or over 85 years (exclusive)
• Did not receive influenza vaccination for the 2018/19 season
• Ineligible to receive 2019/20 influenza vaccination as part of usual care
• Unable to provide informed consent
• Deemed by health care provider to be:
• Too physically frail to participate
• Diagnosed with dementia or other cognitive condition which would make participation difficult
• Insufficient command of English language
• Influenza vaccination contraindicated
• Sufficiently impaired of hearing or vision that exposure to the intervention video content as intended would be compromised
• Those for whom the collection of blood samples is contraindicated
• Those who have participated previously in the pilot study (NCT03144518).