VITAL: Vaccination, Immunity, Time-restricted Eating, Aging and Lifestyle

Launched by CHARITE UNIVERSITY, BERLIN, GERMANY · May 30, 2025

Keywords

ClinConnect Summary

The VITAL trial is a research study looking at how a special eating schedule, called time-restricted eating (TRE), affects older adults' immune responses, particularly after receiving a seasonal flu vaccine. The study will last four weeks and will involve participants aged 60 to 85 who are generally healthy. During the trial, participants will eat within an 8-hour window each day, which means they will fast for 16 hours without consuming any calories. The goal is to see if this eating pattern can improve their immune function and help their bodies respond better to the flu vaccine.

To join the study, participants need to have a body mass index (BMI) between 20 and 35, be willing to get the flu vaccine, and have a scheduled appointment for it. They should also typically eat over 11 hours a day and be able to follow the TRE eating plan. Certain health conditions, recent vaccinations, or specific diets may disqualify individuals from participating. This trial is not yet recruiting, but it aims to provide valuable insights into how dietary habits can impact aging and immune health.

Gender

ALL

Eligibility criteria

• Inclusion Criteria:
• • Male and female participants, enrolled in a 1:1 ratio
• • Age 60-85 years
• • Body mass index (BMI) 20-35 kg/m²
• • Capacity to give informed consent
• • Existing health insurance to allow evaluation and treatment of any incidental findings
• • Usual daily eating window \> 11 hours
• • First meal of the day before 10:00 AM
• • Willingness to receive seasonal influenza vaccination and proof of scheduled appointment
• • Willingness and ability to follow a prescribed TRE dietary regimen (8-hour daily eating window; 16-hour fast without any caloric intake)
• • Influenza-vaccination appointment pre-arranged with primary care physician and coordinated with study team to align with TRE intervention
• Exclusion Criteria:
• • Any vaccination (especially influenza) within 6 months before intervention start
• • Influenza infection within 6 months before intervention start
• • History of severe adverse reactions to prior vaccinations
• • Symptoms of systemic inflammatory or autoimmune disease
• • Immunosuppression (including use of immunosuppressive drugs)
• • Severe hypertension (systolic \> 180 mmHg or diastolic \> 110 mmHg)
• • Any medical condition or functional impairment that, in the investigator's judgment, precludes safe participation
• • Participation in any fasting intervention (e.g., TRE, alternate-day fasting, 5:2, 18:6) within 6 months before enrollment
• • Participation in another diet or weight-loss program (e.g., intensive athletic training)
• • Night-shift or rotating-shift work
• • Severe, active, or unstable medical conditions requiring treatment
• • Chronic use of prescription medications (except hormonal contraception)
• • Postoperative recovery phase
• • Antibiotic therapy within 3 months before enrollment
• • Acute or chronic infections
• • Therapeutic or medically prescribed special diets
• • Food intolerances
• • Vegan diet
• • Current smoker
• • Weight change \> 2 kg in the month before enrollment
• • Known substance, drug, or alcohol abuse
• • Anemia
• • Claustrophobia
• • Legal incapacity or any other circumstance that prevents full understanding of the nature, importance, and implications of the study