Effect of 7 and 13-Valent Pneumococcal Conjugate Vaccines Different Number of Doses for Pneumonia Control in 2008 and 2010 Birth Cohort Children

Impact and Effectiveness of 10 and 13-Valent Pneumococcal Conjugate Vaccines on Hospitalization and Mortality in Children Aged Less than 5 Years in Latin American Countries: A Systematic Review

“…An additional 2 pairs of studies [15, 16] reported on the same population and surveillance data, but used different methods for data analysis. In one case, two studies by the same authors [17, 18] reported on cases from the same area/health services in overlapping periods, but differed in approach (individual vs. aggregate data) and reference group (unvaccinated group with concurrent follow-up data vs. surveillance data from population long before PCV was available). Also related in their dataset were the matched case-control study by Domingues et al [15] and the ancillary study by Verani et al [16], based on cases only (vaccine-type and vaccine related cases) compared to non-vaccine-type disease (“indirect cohort method”).…”

“…Among those studies, 8 evaluated pneumonia hospitalizations only [17, 18, 21, 22, 25–28], 4 evaluated both hospitalized and outpatient pneumonia combined [24, 29–31] two evaluated both pneumonia hospitalizations and deaths [22, 24], and one evaluated only pneumonia deaths [23]. Among the 13 studies, there were 5 interrupted times series [21, 23–25, 32], 6 before-after [17, 27–30], 1 cohort [18] and 1 case-control study [22]. …”

“…When we consider all the above reports on PCV-10 and PCV-13 effectiveness (VE), regardless of outcome, age group, data source and study methodology, VE point estimates varied from a lower 7.4% to 84.6%. Some of the estimates had very wide confidence intervals (Fig 2), whereas two studies [18, 27] presented only point estimates. Another study did not present confidence intervals but reported statistical significance (p-values or “NS”) [17].…”

“…However, estimates using a cohort study design analyzing data obtained by the same surveillance system in the same study population found VE estimates of 84.6% (95% CI not reported) for the <3 year age group. [18]…”

“…In sensitivity analysis, disregarding the outlier estimate reported by Hortal [18], VE for X-ray confirmed pneumonia ranged from 8.8% to 57.9%. In further sensitivity analysis, including only studies assessing hospitalized pneumonia (effectiveness estimates and CI presented in black in Fig 2), and disregarding estimates for combined pneumonia inpatient and outpatient endpoints [24, 29–31] (presented in light gray in Fig 2), VE ranged from 7.4% to 49.3%.…”