Influenza vaccine failure in the tropics: a retrospective cohort study of waning effectiveness
Influenza vaccine effectiveness (VE) wanes over the course of a temperate climate winter season but little data are available from tropical countries with year-round influenza virus activity. In Singapore, a retrospective cohort study of adults vaccinated from 2013 to 2017 was conducted. Influenza v...
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| Main Authors: | , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
02 December 2020
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| In: |
Epidemiology and infection
Year: 2020, Volume: 148, Pages: 1-8 |
| ISSN: | 1469-4409 |
| DOI: | 10.1017/S0950268820002952 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1017/S0950268820002952 Verlag, lizenzpflichtig, Volltext: https://www.cambridge.org/core/journals/epidemiology-and-infection/article/influenza-vaccine-failure-in-the-tropics-a-retrospective-cohort-study-of-waning-effectiveness/87A2CBE95B761D59902B68BC0BDFC65D 
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| Author Notes: | B.E. Young, T.M. Mak, L.W. Ang, S. Sadarangani, H.J. Ho, A. Wilder-Smith, T. Barkham and M. Chen |
| Summary: | Influenza vaccine effectiveness (VE) wanes over the course of a temperate climate winter season but little data are available from tropical countries with year-round influenza virus activity. In Singapore, a retrospective cohort study of adults vaccinated from 2013 to 2017 was conducted. Influenza vaccine failure was defined as hospital admission with polymerase chain reaction-confirmed influenza infection 2-49 weeks after vaccination. Relative VE was calculated by splitting the follow-up period into 8-week episodes (Lexis expansion) and the odds of influenza infection in the first 8-week period after vaccination (weeks 2-9) compared with subsequent 8-week periods using multivariable logistic regression adjusting for patient factors and influenza virus activity. Records of 19 298 influenza vaccinations were analysed with 617 (3.2%) influenza infections. Relative VE was stable for the first 26 weeks post-vaccination, but then declined for all three influenza types/subtypes to 69% at weeks 42-49 (95% confidence interval (CI) 52-92%, P = 0.011). VE declined fastest in older adults, in individuals with chronic pulmonary disease and in those who had been previously vaccinated within the last 2 years. Vaccine failure was significantly associated with a change in recommended vaccine strains between vaccination and observation period (adjusted odds ratio 1.26, 95% CI 1.06-1.50, P = 0.010). |
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| Item Description: | Gesehen am 26.11.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1469-4409 |
| DOI: | 10.1017/S0950268820002952 |