This study aimed to assess the impact of the introduction of pneumococcal conjugate vaccine 13 (PCV13) on the molecular epidemiology of invasive pneumococcal disease (IPD) in children from Andalusia. A population-based prospective surveillance study was conducted on IPD in children aged <14 years from Andalusia (2018–2020). Pneumococcal invasive isolates collected between 2006 and 2009 in the two largest tertiary hospitals in Andalusia were used as pre-PCV13 controls for comparison of serotype/genotype distribution. Overall IPD incidence rate was 3.55 cases per 100 000 in 2018; increased non-significantly to 4.20 cases per 100 000 in 2019 and declined in 2020 to 1.69 cases per 100 000 (incidence rate ratio 2020 vs. 2019: 0.40, 95% confidence interval (CI) 0.20–0.89, P = 0.01). Proportion of IPD cases due to PCV13 serotypes in 2018–2020 was 28% (P = 0.0001 for comparison with 2006–2009). Serotypes 24F (15%) and 11A (8.3%) were the most frequently identified non-PCV13 serotypes (NVT) in 2018–2020. Penicillin- and/or ampicillin-resistant clones mostly belonged to clonal complex 156 (serotype 14-ST156 and ST2944 and serotype 11A-ST6521). The proportion of IPD cases caused by PCV13 serotypes declined significantly after the initiation of the PCV13 vaccination programme in 2016. Certain NVT, such as serotypes 24F and 11A, warrant future monitoring in IPD owing to invasive potential and/or antibiotic resistance rates.

Streptococcus pneumoniae is an important cause of community-acquired pneumonia and pneumococcal conjugate vaccines (PCVs) may reduce this burden. This study's goal was to analyse trends in lower respiratory tract infections (LRTI) hospitalisations before and during a routine vaccination programme targeting all newborns with PCV was started in the province of Quebec, Canada in December 2004. The study population included hospital admissions with a main diagnosis of LRTI among 6–59 month-old Quebec residents from April 2000 to December 2014. Trends in proportions and rates were analysed using Cochran-Armitage tests and Poisson regression models. We observed a general downward trend in all LTRI hospitalisations rate: from 11·55/1000 person-years in 2000–2001 to 9·59/1000 in 2013–2014, a 17·0% reduction, which started before the introduction of PCV vaccination. Downward trends in hospitalisation rates were more pronounced for all-cause of pneumonia (minus 17·8%) than for bronchiolitis (minus 15·4%). There was also a decrease in the mean duration of hospital stay. There was little evidence that all-cause pneumonia decreased over the study period due mainly to the introduction of PCVs. Trends may be related to changes in clinical practice. This study casts doubt on the interpretation of ecological analyses of the implementation of PCV vaccination programmes.

Young age, adverse environmental conditions and infectious agents are established risk factors of lower respiratory tract infection (LRTI), whereas pneumococcal conjugate vaccines may be protective. To explore their relative role as predictors of hospitalizations under the continental climate prevailing in the province of Quebec, Canada, an ecological study was performed. Records with a main diagnosis of LRTI in children born during 2007–2010 and observed up to their second-year anniversary were extracted from the provincial hospital administrative database. Respiratory virus surveillance data and statistics on ambient air temperature were obtained. Vaccine use in different birth cohorts was derived from the Quebec City Immunization Registry. Additive and multiplicative Poisson regression models were applied to estimate attributable fractions. Age, month of birth, ambient temperature, and respiratory syncytial virus (RSV), human metapneumovirus (hMPV) and influenza-positive test proportions were significant predictors of LRTI hospitalizations. No substantial differences were observed in cohorts exposed to the 7-valent or 10-valent pneumococcal conjugate vaccines. In the additive model, the fraction of hospitalizations explained by temperature variation was 37%, whereas RSV circulation explained 28%, hMPV 4% and influenza 1%. Complex interplay between biological, environmental and social mechanisms may explain the important role of ambient air temperature in predicting LRTI hospitalization risk in young children.

We investigated whether straight-line distance from residential compounds to healthcare facilities influenced mortality, the incidence of pneumonia and vaccine efficacy against pneumonia in rural Gambia. Clinical surveillance for pneumonia was conducted on 6938 children living in the catchment areas of the two largest healthcare facilities. Deaths were monitored by three-monthly home visits. Children living >5 km from the two largest healthcare facilities had a 2·78 [95% confidence interval (CI) 1·74–4·43] times higher risk of all-cause mortality compared to children living within 2 km of these facilities. The observed rate of clinical and radiological pneumonia was lower in children living >5 km from these facilities compared to those living within 2 km [rate ratios 0·65 (95% CI 0·57–0·73) and 0·74 (95% CI 0·55–0·98), respectively]. There was no association between distance and estimated pneumococcal vaccine efficacy. Geographical access to healthcare services is an important determinant of survival and pneumonia in children in rural Gambia.

This paper examined whether previously identified community-level factors (high proportion of crowded households and/or persons below the poverty level) remained associated with childhood pneumococcal carriage in the heptavalent pneumococcal conjugate vaccine (PCV7) era. Using logistic regression, individual factors were used to develop base models to which community-level factors were added to evaluate impact on pneumococcal carriage within two paediatric study cohorts from Massachusetts (urban Boston, outside Boston). Six years after introduction of universal childhood PCV7 vaccination, we found no consistent evidence that census tract characteristics (e.g. population size and density, age and race distribution, percent participating in group childcare, parental education, percent lacking in-unit plumbing, poverty, and community stability) affected odds of pneumococcal carriage when added to individual predictors (e.g. younger age, current respiratory tract infections, and attendance in group childcare). How community-level factors influence pneumococcal carriage continues to change in the era of increasing immunization coverage.

In September 2006, the 7-valent pneumococcal conjugate vaccine (PCV7) was added to the UK immunization programme. We aimed to evaluate the impact of PCV7 on the incidence of all-cause community-acquired pneumonia (CAP) in children. A prospective survey was undertaken in 2008–2009 at 11 hospitals in North East England of children aged 0–16 years with radiologically confirmed pneumonia. Data were compared to those from a similar survey undertaken in the same hospitals in 2001–2002. A total of 542 children were enrolled, of which 74% were aged <5 years. PCV7 uptake was 90·7%. The incidence of pneumonia was 11·8/10 000 [95% confidence interval (CI) 10·9–12·9], and the hospitalization rate was 9·9/10 000 (95% CI 9·0–10·9). Compared to 2001, there was a 19% (95% CI 8–29) reduction in the rate of CAP in those aged <5 years, and in those <2 years a 33·1% (95% CI 20–45) reduction in the incidence of CAP and 38·1% (95% CI 24–50) reduction in hospitalization rates. However, for those unvaccinated aged ⩾5 years, there was no difference in the incidence of CAP and hospitalization rate between both surveys. Since 2001, the overall reduction in incidence was 17·7% (95% CI 8–26) and for hospitalization 18·5% (95% CI 8–28). For the <5 years age group there was a lower incidence of CAP in PCV7-vaccinated children (25·2/10 000, 95% CI 22·6–28·2) than in those that were not vaccinated (37·4/10 000, 95% CI 29·2–47·1). In conclusion, PCV7 has reduced both incidence and rate of hospitalization of pneumonia in children, particularly in the <2 years age group.

The 7-valent pneumococcal conjugate vaccine (PCV7) has been included in the routine childhood immunization programme in the UK since September 2006. A population-based study of serotypes causing invasive pneumococcal disease (IPD) post-PCV7 in North East England was conducted using data from a regional enhanced IPD surveillance system. Overall, there was a 20% reduction [95% confidence interval (CI) 5–32] from 12·1 cases/100 000 population in 2006/2007 to 9·7 in 2009/2010. There was a fall in IPD caused by PCV7 serotypes in all age groups, with reductions of 90% (95% CI 61–99) in children aged <5 years, 50% (95% CI 4–75) in persons aged 5–64 years and 66% (95% CI 40–82) in adults aged ⩾65 years. There was a non-significant increase in IPD caused by non-PCV7 serotypes in children aged <5 years of 88% (95% CI −10 to 312) and adults aged ⩾65 years of 12% (95% CI −19 to 50), which was largely caused by serotypes 7F, 19A and 22F. Replacement disease appears to have reduced the benefits of PCV7 in North East England.