scholarly journals Evolution of pneumococcal serotype epidemiology in Botswana following introduction of 13-valent pneumococcal conjugate vaccine

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262225
Author(s):  
Sweta M. Patel ◽  
Yazdani B. Shaik-Dasthagirisaheb ◽  
Morgan Congdon ◽  
Rebecca R. Young ◽  
Mohamed Z. Patel ◽  
...  

Pneumococcal conjugate vaccines reduce the burden of invasive pneumococcal disease, but the sustained effect of these vaccines can be diminished by an increase in disease caused by non-vaccine serotypes. To describe pneumococcal serotype epidemiology in Botswana following introduction of 13-valent pneumococcal conjugate vaccine (PCV-13) in July 2012, we performed molecular serotyping of 268 pneumococcal strains isolated from 221 children between 2012 and 2017. The median (interquartile range) age of the children included in this analysis was 6 (3,12) months. Fifty-nine percent of the children had received at least one dose of PCV-13 and 35% were fully vaccinated with PCV-13. While colonization by vaccine serotypes steadily declined following PCV-13 introduction, 25% of strains isolated more than 3 years after vaccine introduction were PCV-13 serotypes. We also observed an increase in colonization by non-vaccine serotypes 21 and 23B, which have been associated with invasive pneumococcal disease and antibiotic resistance in other settings.

Vaccines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Ezra Linley ◽  
Abigail Bell ◽  
Jenna F. Gritzfeld ◽  
Ray Borrow

Since the introduction of the 13-valent pneumococcal conjugate vaccine, a number of studies have demonstrated the limited efficacy of the pneumococcal serotype 3 component of this vaccine. Evidence from seven countries (Denmark, France, Greece, Portugal, Sweden, UK, US) shows limited or no effectiveness of the 13-valent pneumococcal conjugate vaccine against serotype 3 invasive pneumococcal disease and carriage. The serotype 3 capsule has some unique characteristics that may serve to explain this lack of efficacy—capsular polysaccharide is abundantly expressed, leading to a greater thickness of capsule, and free capsular polysaccharide may be released during growth. The serotype 3 component of the Luminex multiplex assay demonstrates inferior inter-laboratory reproducibility than other components and results may not be reliable. This communication outlines this evidence and discusses whether it is necessary to include serotype 3 in the assay in the future.


2012 ◽  
Vol 31 (9) ◽  
pp. e169-e175 ◽  
Author(s):  
Jenine Leal ◽  
Otto G. Vanderkooi ◽  
Deirdre L. Church ◽  
Judy MacDonald ◽  
Gregory J. Tyrrell ◽  
...  

2021 ◽  
Author(s):  
Marianne Koenraads ◽  
Todd D. Swarthout ◽  
Naor Bar-Zeev ◽  
Comfort Brown ◽  
Jacquline Msefula ◽  
...  

AbstractBackgroundInvasive pneumococcal disease (IPD) in young infants is uncommon but associated with high morbidity and mortality. Accurate data on the burden of IPD in young infants in low-income countries are lacking. We examined the burden of IPD in infants aged <90 days in Blantyre, Malawi over a 14 year period and evaluated the impact of the 12 November 2011 introduction of the 13-valent pneumococcal conjugate vaccine (PCV13) on vaccine-serotype IPD (VT-IPD) in this population.MethodsWe conducted laboratory-based prospective IPD surveillance in infants aged <90 days admitted to Queen Elizabeth Central Hospital (QECH) in Blantyre between 2005 and 2018, including 7 years pre- and 7 years post-PCV13 introduction. IPD was defined as Streptococcus pneumoniae identified by culture from blood or cerebrospinal fluid. Serotypes were determined by multiplex PCR and latex agglutination testing.ResultsWe identified 130 cases of culture-confirmed IPD in infants <90 days old between 2005-2018. Total IPD incidence was declining prior to PCV13 introduction. The mean incidence of IPD was significantly lower in the post-PCV era. Serotypes 5 (27.8%) and 1(15.6%), were most prevalent. Even after PCV13 introduction, VT-IPD remained dominant with serotype 5 accounting for 17.4% and serotype 1 for 13% of cases in young infants.ConclusionVaccine serotypes were the main cause of IPD in neonates and young infants, both before and after PCV13 introduction. Further strategies need to be considered to protect this vulnerable population, including maternal or neonatal immunization and implementation of an alternative PCV schedule with a booster dose.SummaryThe incidence of invasive pneumococcal disease in infants in Blantyre, Malawi has declined over the past decade and more significantly after introduction of the pneumococcal conjugate vaccine. Vaccine serotypes have remained the main cause of disease in this population.


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