Misalignment between Influenza Vaccination Timing and Epidemic Dynamics in Thailand: A Policy Analysis, 2011–2025
DOI:
https://doi.org/10.59096/osir.v19i2.281720Keywords:
influenza, vaccination timing, seasonality, surveillance, policy analysisAbstract
Objectives: To assess the alignment between influenza vaccination timing and epidemic dynamics in Thailand and examine the implications of epidemiological variability, program design, and implementation processes for national influenza vaccination policy.
Methods: We conducted a mixed-methods policy analysis integrating a longitudinal analysis of national influenza surveillance data from 2011–2025, assessment of vaccination program performance, and a rapid systematic review of global evidence. Epidemic onset and seasonal patterns were characterized using weekly case data. Alignment between vaccination timing and epidemic onset was quantified using a lag-time metric, defined as the interval between vaccination initiation and epidemic onset.
Results: Influenza activity demonstrated increasing seasonal variability, transitioning from a single annual peak to more complex patterns with multiple waves and shifting epidemic onset. Across the 15-year study period, dual-wave or multi-wave patterns were identified in multiple years. The national vaccination program achieved consistently high delivery efficiency (>90% of allocated doses administered), although coverage remained uneven across population groups. with a median lag time of +11 weeks. In several years, including 2014, 2019, and 2025, vaccination was initiated after epidemic onset, indicating misalignment between vaccine delivery and transmission dynamics.
Public Health Recommendations: Fixed annual vaccination schedules may not provide optimal protection in settings with variable epidemic timing. Strengthening the integration of real-time surveillance data into vaccination planning is essential. Adaptive strategies, including flexible vaccination timing and region-specific approaches, should be considered to improve alignment with epidemic risk. Simple metrics such as lag-time can support routine monitoring and guide policy adjustment. These actions are critical to enhance the effectiveness of influenza control programs in Thailand and similar countries in tropical settings.
References
Caini S, Andrade W, Badur S, Balmeseda A, Barakat A, Bella A, et al. Temporal patterns of influenza A and B in tropical and temperate countries: what are the lessons for influenza vaccination? PLoS One. 2016;11(3):e0152310. doi:10.1371/journal.pone.0152310.
Alonso WJ, Yu C, Viboud C, Richard SA, Schuck-Paim C, Simonsen L, et al. A global map of hemispheric influenza vaccine recommendations. Nat Commun. 2015;6:8253. doi:10.1038/ncomms9253.
Hirve S, Newman LP, Paget J, Azziz-Baumgartner E, Fitzner J, Bhat N, et al. Influenza seasonality in the tropics and subtropics: when to vaccinate? PLoS One. 2016;11(4):e0153003. doi:10.1371/journal.pone.0153003.
Saha S, Chadha M, Mamun AA, Rahman M, Sturm-Ramirez K, Chittaganpitch M, et al. Influenza seasonality and vaccination timing in tropical and subtropical areas of southern and south-eastern Asia. Bull World Health Organ. 2014;92:318–30. doi:10.2471/BLT.13.124412.
Durand LO, Cheng PY, Palekar R, Clara W, Jara J, Cerpa M, et al. Timing of influenza epidemics and vaccines in the American tropics, 2002-2008, 2011-2014. Influenza Other Respir Viruses. 2016;10(3):170–5. doi:10.1111/irv.12371.
World Health Organization. Vaccines against influenza: WHO position paper. Wkly Epidemiol Rec. 2012;87:461–76.
World Health Organization. Recommended composition of influenza virus vaccines for use in the southern hemisphere. Geneva: World Health Organization; 2023.
Centers for Disease Control and Prevention (US). Influenza vaccination: a summary for clinicians. Atlanta: Centers for Disease Control and Prevention; 2023.
Prachayangprecha S, Vichaiwattana P, Klinfueng S, Schadt EE, Sonsri P, Ruangrung K, et al. Influenza activity in Thailand and occurrence in different climates. Springerplus. 2015;4:356. doi:10.1186/s40064-015-1149-6.
Anupong S, Modchang C, Chadsuthi S. Seasonal patterns of influenza incidence and the influence of meteorological and air pollution factors in Thailand during 2009–2019. Heliyon. 2024;10:e36703. doi:10.1016/j.heliyon.2024.e36703.
Ministry of Public Health, Thailand. Influenza vaccination policy and programme reports. Nonthaburi: Ministry of Public Health; 2024.
National Health Security Office. Annual report on influenza vaccination coverage and programme performance. Bangkok: National Health Security Office; 2025.
Division of Epidemiology, Department of Disease Control. National influenza surveillance reports, 2011–2025. Nonthaburi: Ministry of Public Health; 2025.
National Vaccine Committee, Thailand. National immunization policy and recommendations. Nonthaburi: Ministry of Public Health; 2024.
Spencer JA, Smith MZ, Osthus D, Alexander PC, Del Valle SY. When to vaccinate for seasonal influenza: check the peak forecast. BMC Public Health. 2025 Dec 10;26(1):188. doi:10.1186/s12889-025-25760-z.
Padhi A, Bhatt P, Chauhan J, Rajyaguru B, Agarwal S, Chaudhary A, et al. Seasonality of influenza and optimizing timing of vaccination: systematic review and meta-analysis. Cureus. 2025;17(9):e93607. doi:10.7759/cureus.93607.
Walt G, Gilson L. Reforming the health sector in developing countries: the central role of policy analysis. Health Policy Plan. 1994;9:353–70. doi:10.1093/heapol/9.4.353.
Division of Epidemiology, Department of Disease Control, Ministry of Public Health. Case definition for Communicable Disease Surveillance, Thailand. Nonthaburi: Division of Epidemiology, Department of Disease Control; 2020. 73–4. Thai.
Kosasih H, Roselinda, Nurhayati, Klimov A, Xiyan X, Lindstrom S, et al. Surveillance of influenza in Indonesia, 2003–2007. Influenza Other Respir Viruses. 2013;7(3):312–20. doi:10.1111/j.1750-2659.2012.00403.x.
Suntronwong N, Vichaiwattana P, Klinfueng S, Korkong S, Thongmee T, Vongpunsawad S, et al. Climate factors influence seasonal influenza activity in Bangkok, Thailand. PLoS One. 2020;15(9):e0239729. doi:10.1371/journal.pone.0239729.
Yang W, Lau EHY, Cowling BJ. Influenza dynamics in a tropical urban setting: Ho Chi Minh City. Proc Natl Acad Sci U S A. 2023;120:e2211234120.
National Library of Medicine. PubMed [Internet]. Bethesda (MD): National Library of Medicine (US); [cited 2025 May 10]. <https://pubmed.ncbi.nlm.nih.gov/>
Elsevier. Scopus [Internet]. Amsterdam: Elsevier; [cited 2025 May 10]. <https://www.scopus.com/>
Baumgartner EA, Dao CN, Nasreen S, Bhuiyan MU, Mah-E-Muneer S, Mamun AA, et al. Seasonality, timing, and climate drivers of influenza activity worldwide. J Infect Dis. 2012;206(6):838–46. doi:10.1093/infdis/jis467.
Koul PA, Broor S, Saha S, Barnes J, Smith C, Shaw M, et al. Differences in influenza seasonality by latitude, northern India. Emerg Infect Dis. 2014 Oct;20(10):1723-6. doi: 10.3201/eid2010.140431. PMID: 25279651; PMCID: PMC4193176[NP24.1].
Chadha MS, Potdar VA, Saha S, Koul PA, Broor S, Dar L, et al. Dynamics of influenza seasonality at sub-regional levels in India and implications for vaccination timing. PLoS One. 2015;10(5):e0124122. doi:10.1371/journal.pone.0124122.
Lucero MG, Inobaya MT, Nillos LT, Tan AG, Arguelles VL, Dureza CJ, et al. National Influenza Surveillance in the Philippines from 2006 to 2012: seasonality and circulating strains. BMC Infect Dis. 2016 Dec 19;16(1):762. doi:10.1186/s12879-016-2087-9.
Althouse BM, Flasche S, Minh LN, Thiem VD, Hashizume M, Ariyoshi K, et al. Seasonality of respiratory viruses causing hospitalizations for acute respiratory infections in children in Nha Trang, Vietnam. Int J Infect Dis. 2018 Oct;75:18–25.doi:10.1016/j.ijid.2018.08.001.
El Guerche-Seblain C, Rigoine de Fougerolles A, Sampson S, Jennings L, Van Buynder P, Yu H, et al. Epidemiology and timing of seasonal influenza epidemics in the Asia-Pacific region, 2010–2017: implications for influenza vaccination programs. Influenza Other Respir Viruses. 2019;13(5):451–461. doi:10.1111/irv.12649.
Horwood PF, Karlsson EA, Horm SV, Ly S, Heng S, Chin S, et al. Circulation and characterization of seasonal influenza viruses in Cambodia, 2012-2015. Influenza Other Respir Viruses. 2019 Sep;13(5):465–76. doi:10.1111/irv.12647.
Servadio JL, Thai PQ, Choisy M, Boni MF. Repeatability and timing of tropical influenza epidemics. PLoS Comput Biol. 2023 Jul 19;19(7):e1011317. doi:10.1371/journal.pcbi.1011317.
Wan Puteh SE, Aazmi MS, Aziz MN, Kamarudin N, Sam JI, Thayan R, et al. Cross-sectional study of influenza trends and costs in Malaysia between 2016 and 2018. PLoS One. 2024;19(3):e0301068. doi:10.1371/journal.pone.0301068.
Sharma N, Sharma SP. Seasonal patterns and subtype distribution of influenza viruses in a tertiary care hospital in North India: a one-year observational Study. Cureus. 2025 Oct 12;17(10):e94428. doi:10.7759/cureus.94428.
Chittaganpitch M, Supawat K, Olsen SJ, Waicharoen S, Patthamadilok S, Yingyong T, et al. Influenza viruses in Thailand: 7 years of sentinel surveillance data, 2004–2010. Influenza Other Respir Viruses. 2012 Jul;6(4):276–83. doi:10.1111/j.1750-2659.2011.00302.x.
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