Zitta Barrella Harboe1, Tine Dalby2, Daniel M Weinberger3, Thomas Benfield4, Kåre Mølbak5, Hans Christian Slotved2, Camilla H Suppli5, Helle Bossen Konradsen2, Palle Valentiner-Branth5. 1. National Neisseria and Streptococcus Reference Laboratory, Department of Microbiology and Infection Control, Statens Serum Institut Department of Infectious Diseases, Copenhagen University Hospital, Rigshospitalet, Denmark. 2. National Neisseria and Streptococcus Reference Laboratory, Department of Microbiology and Infection Control, Statens Serum Institut. 3. Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, Connecticut. 4. Department of Infectious Diseases Clinical Research Centre, Copenhagen University Hospital, Hvidovre Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen. 5. Department of Infectious Disease Epidemiology, Statens Serum Institut, Copenhagen, Denmark.
Abstract
BACKGROUND: The impact of the 13-valent pneumococcal conjugate vaccine (PCV13) at the population level is unclear. We explored PCV13's effect in reducing invasive pneumococcal disease (IPD)-related morbidity and mortality, and whether serotype-specific changes were attributable to vaccination or expected as a part of natural, cyclical variations. METHODS: This was a Danish nationwide population-based cohort study based on the linkage of laboratory surveillance data and the Danish Civil Registration System. Changes in IPD incidence and mortality during baseline (2000-2007), 7-valent pneumococcal conjugate vaccine (PCV7) (2008-2010), and PCV13 (2011-2013) periods were estimated. Predicted incidences of serotypes were estimated controlling for cyclical trends from historical patterns observed during the past 20 years. RESULTS: We observed a 21% reduction (95% confidence interval [CI], 17%-25%) in IPD incidence in the total population after PCV13's introduction, and a 71% reduction (95% CI, 62%-79%) in children aged <2 years, considered as the vaccine effectiveness. We estimated a 28% reduction (95% CI, 18%-37%) in IPD-related 30-day mortality, from 3.4 deaths (95% CI, 3.2-3.6) per 100 000 population in the pre-PCV period to 2.4 (95% CI, 2.2-2.7) in the PCV13 period. The decline in mortality was observed across all age groups but was mainly related to mortality reductions in the nonvaccinated population. For serotypes 1 and 3, there were no significant changes in incidence beyond what would be expected from natural cyclical patterns. Serotype 19A significantly increased following PCV7's introduction, but the incidence declined toward baseline in 2012. CONCLUSIONS: PCV13 has brought greater benefits than we had expected in our setting. We observed a further decline on IPD incidence shortly after the shift from PCV7 to PCV13 in the national immunization program. This decline was accompanied by a substantial population-level decline in pneumococcal-related mortality of nearly 30% among nonvaccinated persons.
BACKGROUND: The impact of the 13-valent pneumococcal conjugate vaccine (PCV13) at the population level is unclear. We explored PCV13's effect in reducing invasive pneumococcal disease (IPD)-related morbidity and mortality, and whether serotype-specific changes were attributable to vaccination or expected as a part of natural, cyclical variations. METHODS: This was a Danish nationwide population-based cohort study based on the linkage of laboratory surveillance data and the Danish Civil Registration System. Changes in IPD incidence and mortality during baseline (2000-2007), 7-valent pneumococcal conjugate vaccine (PCV7) (2008-2010), and PCV13 (2011-2013) periods were estimated. Predicted incidences of serotypes were estimated controlling for cyclical trends from historical patterns observed during the past 20 years. RESULTS: We observed a 21% reduction (95% confidence interval [CI], 17%-25%) in IPD incidence in the total population after PCV13's introduction, and a 71% reduction (95% CI, 62%-79%) in children aged <2 years, considered as the vaccine effectiveness. We estimated a 28% reduction (95% CI, 18%-37%) in IPD-related 30-day mortality, from 3.4 deaths (95% CI, 3.2-3.6) per 100 000 population in the pre-PCV period to 2.4 (95% CI, 2.2-2.7) in the PCV13 period. The decline in mortality was observed across all age groups but was mainly related to mortality reductions in the nonvaccinated population. For serotypes 1 and 3, there were no significant changes in incidence beyond what would be expected from natural cyclical patterns. Serotype 19A significantly increased following PCV7's introduction, but the incidence declined toward baseline in 2012. CONCLUSIONS: PCV13 has brought greater benefits than we had expected in our setting. We observed a further decline on IPD incidence shortly after the shift from PCV7 to PCV13 in the national immunization program. This decline was accompanied by a substantial population-level decline in pneumococcal-related mortality of nearly 30% among nonvaccinated persons.
Authors: Alan C Kinlaw; Til Stürmer; Jennifer L Lund; Lars Pedersen; Michael D Kappelman; Julie L Daniels; Trine Frøslev; Christina D Mack; Henrik Toft Sørensen Journal: Pediatrics Date: 2017-08-14 Impact factor: 7.124
Authors: Sergio Torres-Rueda; Helen Ed Burchett; Ulla K Griffiths; Pierre Ongolo-Zogo; Jean-Marie Edengue; Yayehyirad Kitaw; Mitike Molla; Lawrence Gelmon; Washington Onyango-Ouma; Mamadou Konate; Sandra Mounier-Jack Journal: Afr Health Sci Date: 2015-09 Impact factor: 0.927