Effectiveness of Pneumococcal Conjugate Vaccines (PCV7 and PCV13) against Invasive Pneumococcal Disease among Children under Two Years of Age in Germany

Abstract

BackgroundIn this study we calculate the effectiveness of pneumococcal conjugate vaccines (PCV) against invasive pneumococcal disease (IPD) among children under the age of two years using the indirect cohort method. We also discuss the timeliness of vaccination and the residual cases of vaccine type IPD.Methods and FindingsFrom July 2006 until June 2015, 921 IPD cases were reported and for 618 children (67.1%), the vaccination status at the time of infection could be accurately determined. Of these, 379 (61.3%) were vaccinated and 239 (38.7%) were not vaccinated. The adjusted vaccine effectiveness (VE) of PCV7 for all included serotypes + 6A was 80% (95% CI: 63–89) for at least one dose, 97% (89–100) after three primary doses (post primary) and 95% (57–100) post booster. The adjusted overall VE of PCV13 was 86% (74–93) for at least one dose, 85% (62–94) post primary and 91% (61–99) post booster. For the additional serotypes included in PCV13, the adjusted VE was 82% (66–91), 80% (46–93) and 90% (54–98) respectively. The serotype specific VE for at least one dose was high for serotypes 1 (83%; 15–97), 3 (74%; 2–93), 7F (84%; 18–98) and 19A (77%; 47–90). Only 39.5% of children with IPD obtained their first dose of PCV7 according to schedule (2nd dose: 32.9%, 3rd dose: 22.0%, booster dose: 63.6%). For children vaccinated with PCV13 values were slightly better: 43.8%, 33.5%, 26.3% and 74.3% respectively. Among 90 residual cases with PCV7 serotypes, 73 (81.1%) were in unvaccinated children, and 15 (16.7%) in children who had not obtained the number of doses recommended for their age, and only two (2.2%) in children vaccinated according to age. Of 82 cases with PCV13 serotypes occurring after the switch from PCV7 to PCV13, 56 (68.3%) were not vaccinated, 22 (26.8%) were incompletely vaccinated, and four (4.9%) were vaccinated according to age.ConclusionsOur data show a high effectiveness of pneumococcal conjugate vaccination in Germany. However, the administration of vaccine doses among children with IPD is often delayed, resulting in many vaccine type cases in non- or incompletely-vaccinated children. Whether the recently-implemented change to a 2+1 schedule will improve the timeliness of vaccination should be subject to careful monitoring.

Public health impact of pneumococcal conjugate vaccine infant immunization programs: assessment of invasive pneumococcal disease burden and serotype distribution

“…It has been hypothesized that this may be due to the different conjugation methods used for 19F in the two vaccines [92]. PHiD-CV has no impact on serotype 3 disease while effectiveness of PCV13 against serotype 3 disease has been observed in some but not other studies [93][94][95][96]. Serotype-specific information was available for eight children and five adult datasets.…”

Invasive Pneumococcal Disease in Refugee Children, Germany

“…Vaccination in newly arrived refugees presents an opportunity to cost-effectively, safely, and humanely protect a vulnerable population from negative health outcomes resulting from vaccine-preventable diseases ( 13 ). Given that children in Germany with insecure residence status are twice as likely to be incompletely vaccinated ( 2 ), a PCV program for refugee children in Germany might require additional follow-up measures to ensure consistency and provide sufficient protection, particularly because PCV dosing in Germany-born children with IPD has been lax ( 9 ). A PCV program could help reduce antimicrobial drug–resistant pneumococcal infections, the carriage of resistant strains ( 14 ), overall antimicrobial drug use, and the prevalence of resistance genes within the pneumococcal population ( 15 ).…”

“…For the analysis, case isolates were from refugee children with IPD, and control isolates were from Germany-born children with IPD. Refugee status was documented by GNRCS personnel in conjunction with determining vaccination status, as described elsewhere ( 9 ). Because identification of refugee status was tied to the determination of vaccination status, all children with an unknown vaccination status were excluded.…”

Response to: Pneumococcal conjugate vaccines in Latin America: are PCV10 and PCV13 similar in terms of protection against serotype 19A?

“…The study showed a VE of 83% (95% CI 41; 95) against 19A IPD and VE of 100% against IPD due to serotype 7F. An indirect cohort analysis carried out in Germany [6] in children aged 2-24 months, who received at least one dose of PCV13 from July 2010 till June 2015, showed a VE of 77% (95% CI 47; 90) and 84% (95% CI 18; 98) against IPD due to 19A and 7F, respectively. Likewise, an indirect cohort analysis conducted in children aged 4-56 months in the UK [7] showed a VE of 67% (95% CI 33; 84) against 19A IPD and 91% (95% CI 70; 98) against 7F IPD following PCV13 introduction.…”