Background: Influenza and pneumococcal vaccinations play a crucial role in disease prevention among older adults and are recommended to older adults aged 60 years and over in China, but the vaccination rates are suboptimal. Behavioral spillover indicates that a change in one behavior may lead to changes in other related behaviors. Objective: Based on the Behavioral Spillover Theory, this study aimed to investigate the association between influenza vaccination history and pneumococcal vaccination intention, as well as the mediating role of negative attitudes toward general vaccination among older adults in China. Method: A multi-center cross-sectional survey was conducted among 1031 older adults, and 658 participants (median age: 65.0 ± 9.0 years) who had not received pneumococcal vaccination were included in the analysis. Correlation analysis and path analysis were performed. Results: A significant positive association was observed between influenza vaccination history and pneumococcal vaccination intention (r = 0.167, p < 0.001). In contrast, negative attitudes toward general vaccination, including mistrust of vaccine benefits (r = −0.253, p < 0.001), worries about unforeseen future effects (r = −0.180, p < 0.001), concerns about commercial profiteering (r = −0.360, p < 0.001), and a preference for natural immunity (r = −0.212, p < 0.001) were negatively associated with pneumococcal vaccination intention. Negative attitudes toward general vaccination mediated the association between influenza vaccination history and pneumococcal vaccination intention (total indirect effect = 0.119, p < 0.001, effect size = 50.0%). Conclusion: These findings demonstrated that influenza vaccination history may reduce negative attitudes toward general vaccination, which may further increase pneumococcal vaccination intention, indicating spillover effects of influenza vaccination history. To promote vaccination behavior among older adults, addressing negative attitudes toward general vaccination is crucial.

Background: Preexposure prophylaxis (PrEP) is a key biomedical HIV prevention strategy that relies heavily on adherence for optimal effectiveness. In China, most PrEP users purchase their medication online, making it challenging to monitor and support adherence effectively. Objective: This protocol aims to describe a digital intervention developed to monitor and improve the medication adherence of real-world e-consumers of PrEP and an evaluation plan assessing its acceptability, feasibility, and effectiveness. Methods: The Real-Time Monitoring and Precision Intervention for HIV PrEP Adherence (REMOTE) trial is a parallel-group, open-label, online-delivered, active-controlled, and stratified randomized controlled trial conducted among 430 e-consumers of PrEP (320 event-driven regimen users and 110 daily regimen users) in China. People who have purchased PrEP online, have taken PrEP in the previous 3 months, and plan to continue for the next 6 months will be stratified by regimen type and randomized into control and intervention groups at a 1:1 ratio. A WeChat-based digital platform will deliver the REMOTE intervention. The monitoring module follows ecological momentary assessment principles. The intervention design is guided by the stages of change theory, tailoring strategies to different nonadherence risks based on monitoring results. Intervention components include low-risk (health education and an artificial intelligence chatbot), medium-risk (peer forum and admonitory education), and high-risk (customized reminders and physician counseling) strategies. The control group will use a simplified platform with only real-time monitoring. The primary outcome is the proportion of participants achieving optimal adherence for 6 months, assessed via real-time monitoring and validated via surveys at baseline and the 1-, 3-, and 6-month follow-ups. Secondary outcomes include PrEP adherence knowledge, self-efficacy, risk perception, adherence barriers, stigma, and social support, measured via surveys. Intention-to-treat analysis will be conducted. Results: Funding for the study was approved in March 2024. Ethics approval for the study was granted in July 2024. The pilot trial was completed in November 2025. Baseline data collection commenced in January 2026. By February 5, 2026, recruitment and baseline data collection were completed, with 448 participants enrolled. The data have not been viewed by the research team. The intervention is currently ongoing, and the study is expected to conclude in August 2026. Results are anticipated to be published in early 2027. Conclusions: The REMOTE trial pioneers a real-time monitoring and precision intervention for e-consumers of PrEP. Leveraging technology and ecological momentary assessment, it delivers a personalized, real-time intervention that is crucial for adherence. The findings could significantly impact future HIV prevention strategies. Trial Registration: Chinese Clinical Trial Registry ChiCTR2400088278; https://www.chictr.org.cn/showproj.html?proj=236414 International Registered Report Identifier (IRRID): DERR1-10.2196/92750

Background: Oral pre-exposure prophylaxis (PrEP) is highly effective for HIV prevention, but its real-world impact depends on sustained adherence. Long-acting injectable cabotegravir (CAB-LA) may reduce the burden of daily or event-driven pill use. In China, many oral PrEP users obtain medication online, but little is known about their prior CAB-LA awareness or willingness to consider it. Objective: This study assessed prior CAB-LA awareness, hypothetical willingness to use CAB-LA, reported barriers and facilitators, and associated factors among oral PrEP users in China obtaining PrEP online. Methods: This cross-sectional study analyzed baseline data from the Real-world E-consumer Cohort of Oral PrEP (RECOPE), a prospective cohort in China. Participants completed a self-administered web-based questionnaire assessing prior CAB-LA awareness, hypothetical willingness after standardized CAB-LA information, sociodemographic characteristics, recent sexual behaviors and sexually transmitted infection (STI) diagnosis, and oral PrEP-related characteristics. Modified Poisson regression with robust SEs estimated prevalence ratios (PRs) and adjusted prevalence ratios (aPRs) with 95% CIs. Primary regression analyses were restricted to sexually active participants. Results: Among 621 oral PrEP users, the mean age was 29.9 (SD 6.4) years; all were assigned male sex at birth, and 608 (97.9%) identified as men. Overall, 216 of 621 (34.8%, 95% CI 31.1%‐38.6%) participants reported prior CAB-LA awareness. After receiving standardized information, 428 of 621 (68.9%, 95% CI 65.2%‐72.4%) participants expressed hypothetical willingness to use CAB-LA if it became available in China. Convenience was the most frequently reported facilitator among willing participants (395/428, 92.3%), whereas high cost was the most frequently reported barrier among those who did not express willingness (123/193, 63.7%). In adjusted analyses, event-driven PrEP users had a lower prevalence of prior CAB-LA awareness than daily PrEP users (aPR 0.66, 95% CI 0.50‐0.86), whereas participants who had switched oral PrEP regimens in the past 3 months had higher prior awareness (aPR 1.34, 95% CI 1.07‐1.68). Hypothetical willingness was more prevalent among participants reporting an STI diagnosis in the past 3 months (aPR 1.22, 95% CI 1.08‐1.39) and chemsex (aPR 1.13, 95% CI 1.01‐1.26), whereas higher PrEP-related stigma was associated with slightly lower willingness (aPR 0.99 per 1-point increase, 95% CI 0.98‐0.99). Conclusions: Among oral PrEP users in China obtaining PrEP online, prior CAB-LA awareness was limited, whereas hypothetical willingness was common after standardized information was provided. Prior awareness differed by oral PrEP regimen and recent regimen switching, whereas willingness was associated with recent STI diagnosis, chemsex, and PrEP-related stigma. Convenience was a major appeal, while cost remained an important barrier. These findings support improving access to balanced PrEP information and addressing practical barriers as long-acting PrEP becomes more widely available.

BACKGROUND Preexposure prophylaxis (PrEP) is a key biomedical HIV prevention strategy that relies heavily on adherence for optimal effectiveness. In China, most PrEP users purchase their medication online, making it challenging to monitor and support adherence effectively. OBJECTIVE This protocol aims to describe a digital intervention developed to monitor and improve the medication adherence of real-world e-consumers of PrEP and an evaluation plan assessing its acceptability, feasibility, and effectiveness. METHODS The Real-Time Monitoring and Precision Intervention for HIV PrEP Adherence (REMOTE) trial is a parallel-group, open-label, online-delivered, active-controlled, and stratified randomized controlled trial conducted among 430 e-consumers of PrEP (320 event-driven regimen users and 110 daily regimen users) in China. People who have purchased PrEP online, have taken PrEP in the previous 3 months, and plan to continue for the next 6 months will be stratified by regimen type and randomized into control and intervention groups at a 1:1 ratio. A WeChat-based digital platform will deliver the REMOTE intervention. The monitoring module follows ecological momentary assessment principles. The intervention design is guided by the stages of change theory, tailoring strategies to different nonadherence risks based on monitoring results. Intervention components include low-risk (health education and an artificial intelligence chatbot), medium-risk (peer forum and admonitory education), and high-risk (customized reminders and physician counseling) strategies. The control group will use a simplified platform with only real-time monitoring. The primary outcome is the proportion of participants achieving optimal adherence for 6 months, assessed via real-time monitoring and validated via surveys at baseline and the 1-, 3-, and 6-month follow-ups. Secondary outcomes include PrEP adherence knowledge, self-efficacy, risk perception, adherence barriers, stigma, and social support, measured via surveys. Intention-to-treat analysis will be conducted. RESULTS Funding for the study was approved in March 2024. Ethics approval for the study was granted in July 2024. The pilot trial was completed in November 2025. Baseline data collection commenced in January 2026. By February 5, 2026, recruitment and baseline data collection were completed, with 448 participants enrolled. The data have not been viewed by the research team. The intervention is currently ongoing, and the study is expected to conclude in August 2026. Results are anticipated to be published in early 2027. CONCLUSIONS The REMOTE trial pioneers a real-time monitoring and precision intervention for e-consumers of PrEP. Leveraging technology and ecological momentary assessment, it delivers a personalized, real-time intervention that is crucial for adherence. The findings could significantly impact future HIV prevention strategies. CLINICALTRIAL Chinese Clinical Trial Registry ChiCTR2400088278; https://www.chictr.org.cn/showproj.html?proj=236414 INTERNATIONAL REGISTERED REPORT DERR1-10.2196/92750