RANDOMIZED CONTROLLED TRIAL OF TEXT MESSAGE TO INCREASE PNEUMOCOCCAL VACCINATION IN ADULTS IN CHILE.
1 other identifier
interventional
43,000
1 country
1
Brief Summary
The goal of this randomized controlled trial is to learn if text message reminders sent through WhatsApp increase pneumococcal vaccination coverage in adults turning 65 years old in Chile. The main questions it aims to answer are: Do text message reminders increase the proportion of adults aged 65 years who receive the pneumococcal vaccine compared to usual care? Do text message reminders increase pneumococcal vaccination coverage within the first 7 days after the message is sent? Is there an association between socioeconomic factors and pneumococcal vaccination coverage in adults aged 65 years in Chile? Researchers will compare adults who receive a text message reminder to adults who receive no reminder (usual care) to see if the reminders increase vaccination uptake. Participants will: Be randomly assigned to receive a WhatsApp text message reminder about the pneumococcal vaccine or to receive no reminder Receive a second reminder on day 14 if they have not yet been vaccinated (intervention group only) Be followed for 6 weeks, with vaccination status checked at days 7, 21, and 42 from the start of the intervention
Trial Health
Trial Health Score
Automated assessment based on enrollment pace, timeline, and geographic reach
participants targeted
Target at P75+ for not_applicable
Started Jul 2026
Shorter than P25 for not_applicable
1 active site
Health score is calculated from publicly available data and should be used for screening purposes only.
Trial Relationships
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Study Timeline
Key milestones and dates
First Submitted
Initial submission to the registry
June 15, 2026
CompletedFirst Posted
Study publicly available on registry
June 22, 2026
CompletedStudy Start
First participant enrolled
July 15, 2026
CompletedPrimary Completion
Last participant's last visit for primary outcome
September 1, 2026
ExpectedStudy Completion
Last participant's last visit for all outcomes
October 1, 2026
June 22, 2026
June 1, 2026
2 months
June 15, 2026
June 15, 2026
Conditions
Keywords
Outcome Measures
Primary Outcomes (1)
Pneumococcal vaccination coverage at day 42
Proportion of randomized adults in each group who received the 23-valent pneumococcal polysaccharide vaccine (PPV23) within 42 days from the start of the intervention. Vaccination status will be ascertained through the National Immunization Registry (RNI). Coverage will be calculated as the number of vaccinated adults divided by the total number of randomized adults in each group. The association between the intervention and the outcome will be assessed using a chi-square test, and the magnitude of the association will be expressed as relative risk with 95% confidence intervals.
42 days from the start of the intervention
Secondary Outcomes (4)
Pneumococcal vaccination coverage at day 7
7 days from the start of the intervention
Pneumococcal vaccination coverage at day 21
21 days from the start of the intervention
Time to pneumococcal vaccination
42 days from the start of the intervention
Association between sociodemographic factors and pneumococcal vaccination coverage
42 days from the start of the intervention
Study Arms (2)
Text message reminder group
EXPERIMENTALParticipants assigned to this arm will receive a WhatsApp text message reminder on day 0 of the intervention, sent by the Ministry of Health of Chile through the official National Immunization Program contactability platform (EMILIA, Rayén Salud). The message will include an acknowledgment that the participant is eligible for free pneumococcal vaccination upon turning 65 years of age, confirmation that the vaccine is available at no cost, and the name, address, and operating hours of vaccination centers in the participant's municipality of residence. A second reminder message will be sent on day 14 to participants who have not yet been vaccinated. Participants will be followed for 6 weeks, with vaccination status assessed at days 7, 21, and 42 from the start of the intervention.
Usual care group
NO INTERVENTIONParticipants assigned to this arm will not receive a text message reminder. They will be informed of the pneumococcal vaccination recommendation through the usual communication channels of the National Immunization Program, including written press, digital media, and official social media accounts of the Ministry of Health of Chile. Vaccination status will be assessed at days 7, 21, and 42 from the start of the intervention, using the National Immunization Registry (RNI) as the data source.
Interventions
A text message reminder sent via WhatsApp on day 0 of the intervention by the Ministry of Health of Chile, through the official National Immunization Program contactability platform EMILIA (Rayén Salud). The message includes: (1) an official presentation identifying the Ministry of Health of Chile as the sender; (2) a reminder that the recipient is eligible for free pneumococcal vaccination upon turning 65 years of age; (3) confirmation that the 23-valent pneumococcal polysaccharide vaccine (PPV23) is guaranteed and available at no cost through the National Immunization Program; and (4) the name, address, and operating hours of vaccination centers in the participant's municipality of residence. A second reminder message with identical content will be sent on day 14 to participants in the intervention arm who have not yet received the vaccine. The message was developed by the National Immunization Program and the Ministry of Health Communications Unit, based on the Yale-UNICEF Vaccine M
Eligibility Criteria
You may qualify if:
- Adults born during the year 1961, turning 65 years of age in 2026
- Resident in Chile at the time of the study
- Valid mobile phone number registered in the National Immunization Registry (RNI)
You may not qualify if:
- Record of pneumococcal vaccination in the National Immunization Registry (RNI).
- Identified as deceased in the Chilean Civil Registry and Identification Service.
Contact the study team to confirm eligibility.
Sponsors & Collaborators
- Pablo Tomás Valenzuela Garcíalead
- Ministry of Health, Chilecollaborator
Study Sites (1)
National Immunization Program, Ministry of Health, Chile.
Santiago, RM, 8320064, Chile
Related Publications (8)
Yale Institute for Global Health, & United Nations Children's Fund. (2020). Vaccine messaging guide. UNICEF. unicef.org
RESULTData Reportal (2025), "Digital 2025: Chile", retrieved from https://datareportal.com/reports/digital-2025-chile on May 7th 2026.
RESULTComité Asesor en Vacunas y Estrategias de Inmunización de Chile. Recomendación del CAVEI Sobre Vacunación Neumocócica [Internet]. Chile; noviembre de 2025 [citado 7 de mayo de 2026]. Disponible en: https://vacunas.minsal.cl/wp-content/uploads/2025/11/Recomendacion-del-CAVEI-sobre-vacunacion-antineumococica-1.pdf
RESULTCalvo M, Inostroza J, Bastias M, Dabanch J, Cerda J, Gonzalez C, Saldana A, Diaz E, Endeiza ML, Rodriguez J, Santillana S, Acevedo J. [CAVEI recommendation for pneumococcal vaccine use in adults]. Rev Chilena Infectol. 2020 Feb;37(1):47-50. doi: 10.4067/S0716-10182020000100047. No abstract available. Spanish.
PMID: 32730400RESULTInstituto de Salud Pública/MINSAL. Informe de Vigilancia enfermedad invasora por S. pneumoniae Chile 2024.
RESULTWHO. Considerations for pneumococcal vaccination in older adults. Wkly Epidemiol Rec 2021;96(23):217-228.
RESULTLouw GE, Hohlfeld AS, Kalan R, Engel ME. Mobile Phone Text Message Reminders to Improve Vaccination Uptake: A Systematic Review and Meta-Analysis. Vaccines (Basel). 2024 Oct 8;12(10):1151. doi: 10.3390/vaccines12101151.
PMID: 39460318RESULTScelfo C, Menzella F, Fontana M, Ghidoni G, Galeone C, Facciolongo NC. Pneumonia and Invasive Pneumococcal Diseases: The Role of Pneumococcal Conjugate Vaccine in the Era of Multi-Drug Resistance. Vaccines (Basel). 2021 Apr 22;9(5):420. doi: 10.3390/vaccines9050420.
PMID: 33922273RESULT
Related Links
MeSH Terms
Conditions
Condition Hierarchy (Ancestors)
Study Officials
- PRINCIPAL INVESTIGATOR
Pablo Valenzuela García, MD, MSc
Pontifical Catholic University of Chile. National Immunization Program, Ministry of Health, Chile.
- STUDY DIRECTOR
Ignacio Castro Aguirre, MD; MPH
National Immunization Program, Ministry of Health, Chile.
Central Study Contacts
Study Design
- Study Type
- interventional
- Phase
- not applicable
- Allocation
- RANDOMIZED
- Masking
- NONE
- Purpose
- PREVENTION
- Intervention Model
- PARALLEL
- Sponsor Type
- OTHER
- Responsible Party
- SPONSOR INVESTIGATOR
- PI Title
- Specialist in Adult Infectious Diseases and Epidemiologist, UC. Advisor to the National Immunization Program, Ministry of Health, Chile.
Study Record Dates
First Submitted
June 15, 2026
First Posted
June 22, 2026
Study Start
July 15, 2026
Primary Completion (Estimated)
September 1, 2026
Study Completion (Estimated)
October 1, 2026
Last Updated
June 22, 2026
Record last verified: 2026-06
Data Sharing
- IPD Sharing
- Will not share
Individual participant data contain personal identifiers obtained from a national administrative registry (RNI) protected under Chilean Law No. 19,628 on the Protection of Private Life. Sharing of individual participant data is therefore not legally permissible. Aggregate results will be available upon publication of the study findings.