Related Experiment Video
Updated: Mar 22, 2026
Experimental Human Pneumococcal Carriage
Published on: February 15, 2013
Effectiveness of the 10-Valent Pneumococcal Conjugate Vaccine (PCV-10) in Children in Chile: A Nested Case-Control
Janepsy Diaz1, Solana Terrazas1, Ana L Bierrenbach2
1National Institute of Health, Santiago, Chile.
Insights
The ten-valent pneumococcal conjugate vaccine (PCV10) significantly reduced infant pneumonia hospitalizations and deaths in Chile. This vaccine effectiveness study highlights the impact of PCV10 on public health outcomes.
Area of Science:
- Pediatric Infectious Diseases
- Vaccinology
- Public Health Surveillance
Background:
- The ten-valent pneumococcal conjugate vaccine (PCV10) was integrated into Chile's National Immunization Program (NIP) in January 2011.
- The vaccination schedule involved a 3+1 dosing regimen (2, 4, 6, and 12 months) without a catch-up campaign.
Purpose of the Study:
- To assess the effectiveness of PCV10 in reducing pneumonia-related hospitalizations and mortality among infants.
- To evaluate the impact of PCV10 during the initial two years following its introduction into the national immunization program.
Main Methods:
- A population-based, nested case-control study design was employed.
- Data were sourced from merged nationwide electronic health registries, including live births, vaccinations, hospitalizations, and mortality records.
- Children born in 2010 and 2011 were followed for two years, with pneumonia cases defined using various criteria, and matched to controls for vaccination status assessment via conditional logistic regression.
Main Results:
- The study analyzed 497,996 infants from the 2010 and 2011 birth cohorts.
- PCV10 demonstrated an 11.2% vaccine effectiveness (VE) against all pneumonia hospitalizations and deaths.
- VE increased to 20.7% when viral pneumonia was excluded, and showed significant effectiveness against pneumonia deaths (71.5%) and all-cause deaths (34.8%).
Conclusions:
- PCV10 vaccination significantly decreased pneumonia hospitalizations and mortality, including all-cause deaths, in Chilean infants.
- The study underscores the critical role of robust health information systems for accurate vaccine effectiveness measurement.
Background:
The ten-valent pneumococcal conjugate vaccine (PCV10) was introduced into the Chilean National Immunization Program (NIP) in January 2011 with a 3+1 schedule (2, 4, 6 and 12 months) without catch-up vaccination. We evaluated the effectiveness of PCV10 on pneumonia morbidity and mortality among infants during the first two years after vaccine introduction.
Methods:
This is a population-based nested case-control study using four merged nationwide case-based electronic health data registries: live birth, vaccination, hospitalization and mortality. Children born in 2010 and 2011 were followed from two moths of age for a period of two years. Using four different case definitions of pneumonia hospitalization and/or mortality (all-cause and pneumonia related deaths), all cases and four randomly selected matched controls per case were selected. Controls were matched to cases on analysis time. Vaccination status was then assessed. Vaccine effectiveness (VE) was estimated using conditional logistic regression.
Results:
There were a total of 497,996 children in the 2010 and 2011 Chilean live-birth cohorts. PCV10 VE was 11.2% (95%CI 8.5-13.6) when all pneumonia hospitalizations and deaths were used to define cases. VE increased to 20.7 (95%CI 17.3-23.8) when ICD10 codes used to denote viral pneumonia were excluded from the case definition. VE estimates on pneumonia deaths and all-cause deaths were 71.5 (95%CI 9.0-91.8) and 34.8 (95% CI 23.7-44.4), respectively.
Conclusion:
PCV10 vaccination substantially reduced the number of hospitalizations due to pneumonia and deaths due to pneumonia and to all-causes over this study period. Our findings also reinforce the importance of having quality health information systems for measuring VE.
