Koen Vink , Tamara M.J. Brouwers , Lisa Beckers , Debbie Smit , Martijn Vos , Teun Guichelaar , Tobias N. Bonten , Laura Kervezee , Debbie van Baarle , Jacco Wallinga
{"title":"The Chrono-Vax trial protocol: The effect of the time of day of influenza vaccination on immune responses in adults aged 60–85 years","authors":"Koen Vink , Tamara M.J. Brouwers , Lisa Beckers , Debbie Smit , Martijn Vos , Teun Guichelaar , Tobias N. Bonten , Laura Kervezee , Debbie van Baarle , Jacco Wallinga","doi":"10.1016/j.cct.2025.108040","DOIUrl":null,"url":null,"abstract":"<div><div>Increasing evidence suggests that timing of vaccine administration affects immune responses, with some studies indicating that morning administration of the influenza vaccine elicits a stronger antibody response than afternoon vaccination in older adults. Existing trials focused on antibody responses, contrasting two time groups (morning versus afternoon), without assessing other immunological parameters, such as T-cell responses, which also play a crucial role in immunity to respiratory viruses and may contribute to the time-of-day dependent response to vaccination. Therefore, the Chrono-Vax trial aims to determine the effect of influenza vaccination timing on antibody and T-cell responses across a continuous time window from 09:00–17:00 to gain novel insights into an optimal administration time. Additionally, this study will investigate how chronotype influences the relationship between vaccination timing and vaccine-induced immune responses and examine the impact of vaccination timing on the incidence of influenza-like illness (ILI) and influenza infection up to six months post-vaccination. A total of 440 adults aged 60–85 years will be included in the trial and receive the seasonal influenza vaccine at a random time between 09:00 and 17:00. Blood samples will be collected at baseline and 28 days post-vaccination to determine vaccine-induced immune responses. ILI symptoms and influenza infection will be monitored by participants up to six months after vaccination using a diary and rapid diagnostic self-tests, respectively. As such, the Chrono-Vax trial aims to determine the optimal time of day for influenza vaccination, thereby contributing to more effective vaccination strategies and increased protection against severe disease in older adults.</div></div>","PeriodicalId":10636,"journal":{"name":"Contemporary clinical trials","volume":"156 ","pages":"Article 108040"},"PeriodicalIF":1.9000,"publicationDate":"2025-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Contemporary clinical trials","FirstCategoryId":"3","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1551714425002344","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MEDICINE, RESEARCH & EXPERIMENTAL","Score":null,"Total":0}
引用次数: 0
Abstract
Increasing evidence suggests that timing of vaccine administration affects immune responses, with some studies indicating that morning administration of the influenza vaccine elicits a stronger antibody response than afternoon vaccination in older adults. Existing trials focused on antibody responses, contrasting two time groups (morning versus afternoon), without assessing other immunological parameters, such as T-cell responses, which also play a crucial role in immunity to respiratory viruses and may contribute to the time-of-day dependent response to vaccination. Therefore, the Chrono-Vax trial aims to determine the effect of influenza vaccination timing on antibody and T-cell responses across a continuous time window from 09:00–17:00 to gain novel insights into an optimal administration time. Additionally, this study will investigate how chronotype influences the relationship between vaccination timing and vaccine-induced immune responses and examine the impact of vaccination timing on the incidence of influenza-like illness (ILI) and influenza infection up to six months post-vaccination. A total of 440 adults aged 60–85 years will be included in the trial and receive the seasonal influenza vaccine at a random time between 09:00 and 17:00. Blood samples will be collected at baseline and 28 days post-vaccination to determine vaccine-induced immune responses. ILI symptoms and influenza infection will be monitored by participants up to six months after vaccination using a diary and rapid diagnostic self-tests, respectively. As such, the Chrono-Vax trial aims to determine the optimal time of day for influenza vaccination, thereby contributing to more effective vaccination strategies and increased protection against severe disease in older adults.
期刊介绍:
Contemporary Clinical Trials is an international peer reviewed journal that publishes manuscripts pertaining to all aspects of clinical trials, including, but not limited to, design, conduct, analysis, regulation and ethics. Manuscripts submitted should appeal to a readership drawn from disciplines including medicine, biostatistics, epidemiology, computer science, management science, behavioural science, pharmaceutical science, and bioethics. Full-length papers and short communications not exceeding 1,500 words, as well as systemic reviews of clinical trials and methodologies will be published. Perspectives/commentaries on current issues and the impact of clinical trials on the practice of medicine and health policy are also welcome.