The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children.
Observational evidence suggests that pneumococcal conjugate vaccines (PCVs) are more effective at reducing the incidence of hypoxaemic pneumonia compared to non-hypoxaemic pneumonia. We examined the impact of 10-valent PCV (PCV10, Synflorix) on hypoxaemic pneumonia hospital admissions using data fro...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2025-01-01
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| Series: | PLOS Global Public Health |
| Online Access: | https://doi.org/10.1371/journal.pgph.0004888 |
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| author | Ilsa L Haeusler E Wangeci Kagucia Christian Bottomley Mark Otiende Joyce Nyiro J Anthony G Scott |
| author_facet | Ilsa L Haeusler E Wangeci Kagucia Christian Bottomley Mark Otiende Joyce Nyiro J Anthony G Scott |
| author_sort | Ilsa L Haeusler |
| collection | DOAJ |
| description | Observational evidence suggests that pneumococcal conjugate vaccines (PCVs) are more effective at reducing the incidence of hypoxaemic pneumonia compared to non-hypoxaemic pneumonia. We examined the impact of 10-valent PCV (PCV10, Synflorix) on hypoxaemic pneumonia hospital admissions using data from an existing PCV impact study of clinical and radiographic pneumonia. PCV10 was introduced, with catch-up among children under 5 years, in the Kilifi Health and Demographic Surveillance System (KHDSS) in January 2011. We undertook an interrupted time-series (ITS) analysis using seasonally-adjusted segmented Poisson regression of hypoxaemic and non-hypoxaemic pneumonia, accounting for secular trends, from January 2007 to December 2019 among KHDSS residents aged 2-59 months. The median monthly crude incidence of hypoxaemic pneumonia per 100,000 person-years was 95 (IQR 80-139) in the pre-PCV10 period. Time-series regression estimated PCV10 introduction was associated with an increase in the incidence of hypoxaemic pneumonia in children aged 2-59 months (IRR 1.63, 95% CI 1.10-2.41), whereas it was associated with a decrease in the incidence of non-hypoxaemic pneumonia (IRR 0.61, 95% CI 0.48-0.77). Despite the consistent pneumonia surveillance and robust ITS analysis which accounted for pre-PCV10 secular trend and seasonality, the apparent association with hypoxaemic pneumonia is likely due to unmeasured time-varying confounders around the time of vaccine introduction, such as the epidemiology of other respiratory pathogens. This study highlights limitations in the analysis and interpretation of observational data in vaccine impact studies against pneumonia. |
| format | Article |
| id | doaj-art-f6cb2d035cc64ad8a8a687e876564b68 |
| institution | Kabale University |
| issn | 2767-3375 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLOS Global Public Health |
| spelling | doaj-art-f6cb2d035cc64ad8a8a687e876564b682025-08-20T04:00:34ZengPublic Library of Science (PLoS)PLOS Global Public Health2767-33752025-01-0157e000488810.1371/journal.pgph.0004888The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children.Ilsa L HaeuslerE Wangeci KaguciaChristian BottomleyMark OtiendeJoyce NyiroJ Anthony G ScottObservational evidence suggests that pneumococcal conjugate vaccines (PCVs) are more effective at reducing the incidence of hypoxaemic pneumonia compared to non-hypoxaemic pneumonia. We examined the impact of 10-valent PCV (PCV10, Synflorix) on hypoxaemic pneumonia hospital admissions using data from an existing PCV impact study of clinical and radiographic pneumonia. PCV10 was introduced, with catch-up among children under 5 years, in the Kilifi Health and Demographic Surveillance System (KHDSS) in January 2011. We undertook an interrupted time-series (ITS) analysis using seasonally-adjusted segmented Poisson regression of hypoxaemic and non-hypoxaemic pneumonia, accounting for secular trends, from January 2007 to December 2019 among KHDSS residents aged 2-59 months. The median monthly crude incidence of hypoxaemic pneumonia per 100,000 person-years was 95 (IQR 80-139) in the pre-PCV10 period. Time-series regression estimated PCV10 introduction was associated with an increase in the incidence of hypoxaemic pneumonia in children aged 2-59 months (IRR 1.63, 95% CI 1.10-2.41), whereas it was associated with a decrease in the incidence of non-hypoxaemic pneumonia (IRR 0.61, 95% CI 0.48-0.77). Despite the consistent pneumonia surveillance and robust ITS analysis which accounted for pre-PCV10 secular trend and seasonality, the apparent association with hypoxaemic pneumonia is likely due to unmeasured time-varying confounders around the time of vaccine introduction, such as the epidemiology of other respiratory pathogens. This study highlights limitations in the analysis and interpretation of observational data in vaccine impact studies against pneumonia.https://doi.org/10.1371/journal.pgph.0004888 |
| spellingShingle | Ilsa L Haeusler E Wangeci Kagucia Christian Bottomley Mark Otiende Joyce Nyiro J Anthony G Scott The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children. PLOS Global Public Health |
| title | The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children. |
| title_full | The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children. |
| title_fullStr | The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children. |
| title_full_unstemmed | The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children. |
| title_short | The impact of 10-valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non-hypoxaemic pneumonia in Kenyan children. |
| title_sort | impact of 10 valent pneumococcal conjugate vaccine on the incidence of admissions to hospital with hypoxaemic and non hypoxaemic pneumonia in kenyan children |
| url | https://doi.org/10.1371/journal.pgph.0004888 |
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