Effectiveness of 10-valent pneumococcal conjugate vaccine against vaccine-type invasive pneumococcal disease in Pakistan

Abstract

To assess the effectiveness of 10-valent pneumococcal conjugate vaccine (PCV10) against invasive pneumococcal disease (IPD) due to vaccine serotypes of Streptococcus pneumoniae post introduction of the vaccine into the routine immunization program in Pakistan. Methods: A matched case-control study was conducted at 16 hospitals in Sindh Province, Pakistan. Children aged <5 years (eligible to receive PCV10) who presented with radiographically confirmed pneumonia and/or meningitis were enrolled as cases. PCR for the lytA gene was conducted on blood (for radiographic pneumonia) and cerebrospinal fluid (for meningitis) samples to detect S. pneumoniae. The proportion of IPD due to vaccine serotypes (including vaccine-related serogroups) was determined through serial multiplex PCR. For each case, at least five controls were enrolled from children hospitalized at the same institution, matched for age, district, and season. Results: Of 92 IPD patients enrolled during July 2013 to March 2017, 24 (26.0%) had disease caused by vaccine serotypes. Most case (87.5% of 24) and control (66.4% of 134) children had not received any PCV10 doses. The estimated effectiveness of PCV10 against vaccine-type IPD was 72.7% (95% confidence interval (CI) À7.2% to 92.6%) with at least one dose, 78.8% (95% CI À11.9% to 96.0%) for at least two doses, and 81.9% (95% CI À55.7% to 97.9%) for all three doses of vaccine. Conclusions: The vaccine effectiveness point estimates for PCV10 were high and increased with increasing number of doses. However, vaccine effectiveness estimates did not reach statistical significance, possibly due to low power. The findings indicate the likely impact of vaccine in reducing the burden of vaccinetype IPD if vaccine uptake can be improved.

Strain features of pneumococcal isolates in the pre- and post-PCV10 era in Pakistan

“…Recognizing that PCV10 has been part of the EPI in Pakistan since October 2012 [ 3 ], we report here for the first time on the biology of the pneumococcal population from Pakistan between 2006 and 2020 using whole genome sequencing data.…”

“…Despite high mortality rates associated with pneumococcal infections and recommendations for continuous surveillance of the pneumococcal population at the regional level, only a limited number of studies have reported on serotype distribution of pneumococci in Pakistan. Previous studies have reported high serotype diversity and low coverage (30-74 %) of circulating serotypes by the currently available PCVs (PCV10 and PCV13) [3,[5][6][7][8][9][10]. However, none of these studies evaluated the diversity of pneumococcal lineages [i.e.…”

“…To reduce the burden of pneumococcal infection, Pakistan was the first among South Asian countries to introduce the 10-valent pneumococcal conjugate vaccine (PCV10) in its routine immunization programme in October 2012. The regimen currently in use in Pakistan is three doses given at 6, 10 and 14 weeks of life with no catch-up programme [ 3 ]. Between 2013 and 2015, PCV10 coverage was reportedly increasing (65 % in 2013 to 80 % in 2015), but it plateaued in 2016.…”

A Narrative Review of Pneumococcal Disease in Children in the Philippines

“…In Pakistan, a matched case-control study conducted at 16 hospitals in Sindh Province, in children aged \ 5 years from July 2013 to March 2017, showed the estimated efficacy of PCV10 against vaccine-type IPD was 72.7% (95% CI -7.2%, 92.6%) with at least one dose [66]. The vaccine efficacy point estimates for PCV10 were high and increased with increasing number of doses.…”

Pneumococcal disease in Thailand

“…The introduction of PCV13 resulted in decreases (28%-52%) in colonization by vaccine serotypes in children aged 5 weeks to 23 months (Su et al, 2016;Lu et al, 2019;Chen et al, 2019). More recently, a study conducted in 2013-2017 of children aged <5 years in Pakistan showed the estimated effectiveness of PCV10 as 72.7% after at least one dose (Riaz et al, 2019).…”