C. G. Whitney, United States of America

Centres for Disease Control and Preventio Bacterial diseases

Poster Author Of 1 e-Poster

Online Abstracts Vaccines - Impact of Vaccine programs and Serotype Replacement C2 Impact of Vaccine programs and Serotype Replacement

Author Of 2 Presentations

PREVALENCE OF VACCINE-TYPE PNEUMOCOCCAL CARRIAGE FIVE YEARS AFTER 13-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV13) INTRODUCTION IN GHANA (ID 663)

Abstract

Background

Outbreaks of vaccine-type (VT) pneumococcal meningitis, especially serotype 1 (ST1), continue in Ghana despite PCV13 introduction in 2012 (6, 10, and 14-week schedule) and coverage >85%. We assessed VT-pneumococcal carriage prevalence, focusing on ST1, during the 2018 meningitis season

Methods

We conducted a cross-sectional nasopharyngeal (NP) carriage survey from February-July in three northern Ghana “meningitis belt” regions. Individuals aged 6 weeks-35 years with respiratory symptoms or clinical signs of meningitis were recruited from emergency departments across 6 hospitals. Pneumococci isolated from NP swabs were serotyped by Quellung; ST1 isolates were sequenced.

Results

Among 934 participants, 671 (71.8%) carried pneumococci. Overall and VT-pneumococcal carriage were 76.3% (464/608) and 21.5% (131/608) in <5 years, 67.4% (116/172) and 26.7% (46/172) in 5-14 years, and 59.1% (91/154) and 19.5% (30/154) in 15-35 years, respectively. ST1 colonization was lower in participants <5 versus ≥ 5 years-old (0.3% [2/608] vs. 3.1% [10/326]; P=0.001). All ST1 isolates were sequence type 217/303, but not closely related. Serotypes 3, 19F, 23F, 6A and 14 were the most prevalent PCV13-types.

Conclusions

VT-pneumococcal carriage remains common in Ghana, with ST1 colonization more common among those too old to have received PCV13. Vaccination strategies to decrease VT-pneumococcal transmission are needed.

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SERO-REPLACEMENT WITH NON-VACCINE SEROTYPES POST INTRODUCTION OF PCV10 IN NASOPHARYNX OF CHILDREN IN A RURAL COMMUNITY IN PAKISTAN (ID 1104)

Abstract

Background

Ten-valent pneumococcal vaccine (PCV10) was introduced in Pakistan’s immunization program in 2012. It is important to monitor changing sero- epidemiology post introduction for relevance of existing vaccine formulation.

Methods

From 2014 to 2018, children under the age of 2 years were enrolled from a rural district in Pakistan. Nasopharyngeal swabs were collected and serotyping was done using Multiplex PCR.

Results

Of the 3140 children enrolled, pneumococcal isolates were detected in 2370(75%). VT carriage decreased from 16·1% to 9·6% (p-value< 0·001) over 4 years. There was a significant decline in VT serotypes 6B, 9V/9A and 19F only. The carriage of serotype 19A significantly increased from 4.0% to 6.8% (p-value< 0·001). This increase was more pronounced in vaccinated group. There was no significant change in the ten most common NVT serotypes except for 10A, which increased over time. There was no decline noted in carriage rate for serotype 6A.

Conclusions

We observed an ongoing shift in the pneumococcal carriage of serotypes in children in the rural community. Since the pneumococcal serotypes associated with carriage and Invasive disease are constantly changing, monitoring is necessary to assess the impact of the vaccine and to develop better vaccination strategies.

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