David Goldblatt, United Kingdom
Presenter of 1 Presentation
PNEUMOCOCCAL CARRIAGE AND ANTIBODY PERSISTENCE FOLLOWING PCV13 DELIVERED AS ONE PRIMARY AND ONE BOOSTER (1+1) VERSUS TWO PRIMARY DOSES AND A BOOSTER IN UK INFANTS (ID 900)
- David Goldblatt, United Kingdom
- Nick Andrews, United Kingdom
- Carmen L. Sheppard, United Kingdom
- Samuel Rose,
- Parvinder Aley,
- Lucy Roalfe, United Kingdom
- Hannah Robinson,
- Emma Pearce,
- Emma Plested,
- Marina Johnson,
- David Litt, United Kingdom
- Norman K. Fry, United Kingdom
- Matthew Snape, United Kingdom
- Elizabeth Miller,
Author Of 10 Presentations
THE EMERGENCE OF A STREPTOCOCCUS PNEUMONIAE SEROTYPE 3 VARIANT CARRIAGE IN THE 8 YEARS FOLLOWING POST-PCV13 INTRODUCTION IN BLANTYRE, MALAWI. (ID 606)
Abstract
Background
Several studies have demonstrated limited PCV13 efficacy against carriage of serotype 3 Streptococcus pneumoniae. In Blantyre, no direct vaccine effect was identified on serotype 3 carriage 8 years after PCV13 introduction, and population-based serology showed limited induction of serotype 3-specific antibodies by vaccine or natural exposure. We hypothesised that sequence variability of the CPS locus could at least partly explain these observations.
Methods
CPS loci of 540 serotype 3 isolates (from Africa, Asia, Europe and America) were analysed. ML-phylogeny, antimicrobial resistance (tetM, mefA, ermB, cat gene presence and pbpX allelic profiles) and MLST were calculated. Colony morphology was assessed in microaerophilic and anaerobic conditions.
Results
We identified a serotype 3 CPS locus variant in 82% of Blantyre isolates (2015-2019), characterized by an 8-gene cluster deletion but unchanged colony morphology. This variant appeared independently in at least 3 distinct phylogenetic clusters, including ST700 and ST3214. These strains are characterised by the presence of AMR genes and higher MIC to penicillin. The missing CPS genes have hypothetical protein annotation.
Conclusions
This CPS variant segregated with an AMR genotype, which may have contributed to its emergence. Whether this CPS variation will influence immunogenicity remains to be determined.
HEAD-TO-HEAD COMAPRISON OF TEN-VALENT (PCV10) AND 13-VALENT (PCV13) PNEUMOCOCCAL CONJUGATE VACCINE FOLLWING TWO-DOSE PRIMARY SERIES AND AFTER BOOSTER- DOSE IN SOUTH AFRICA: RANDOMISED CONTROLED TRIAL (ID 1164)
RAPID WANING OF VACCINE-INDUCED IMMUNITY AMONG PCV13-VACCINATED CHILDREN UNDER 5 YEARS OLD IN MALAWI WITH SUBSEQUENT ACQUISITION OF NATURAL ANTIBODY THROUGH NATURAL EXPOSURE (ID 267)
PNEUMOCOCCAL CARRIAGE AND ANTIBODY PERSISTENCE FOLLOWING PCV13 DELIVERED AS ONE PRIMARY AND ONE BOOSTER (1+1) VERSUS TWO PRIMARY DOSES AND A BOOSTER IN UK INFANTS (ID 900)
- David Goldblatt, United Kingdom
- Nick Andrews, United Kingdom
- Carmen L. Sheppard, United Kingdom
- Samuel Rose,
- Parvinder Aley,
- Lucy Roalfe, United Kingdom
- Hannah Robinson,
- Emma Pearce,
- Emma Plested,
- Marina Johnson,
- David Litt, United Kingdom
- Norman K. Fry, United Kingdom
- Matthew Snape, United Kingdom
- Elizabeth Miller,
PNEUMOCOCCAL CONJUGATE VACCINE DOSE-RANGING STUDIES IN HUMANS: A SYSTEMATIC REVIEW (ID 268)
Abstract
Background
Reduced dose vaccination with pneumococcal conjugate vaccines may protect against infection. We sought to examine the relationship between the dose of polysaccharide in conjugate vaccines (PCVs) and immunogenicity.
Methods
A systematic review of English publications that evaluated variable dose immunogenicity of PCVs in humans was performed in Medline and Embase databases (Ovid SP) in August 2019. Results were synthesised descriptively due to the heterogeneity of product valency, content and vaccine schedule.
Results
We identified 1691 articles after de-duplication; 9 studies met our inclusion criteria; 2 in adults, 6 in children and 1 in both. Doses of polysaccharide evaluated ranged from 0.44 mcg to 17.6 mcg. Thirty days after vaccination following a single dose or 2p+1 schedule, all doses tested in infants achieved mean IgG concentrations (GMCs) above the acceptable correlate of protection (COP; 0.35 mcg) and only three GMCs' 95% confidence intervals crossed the COP. All doses tested in adults achieved GMCs that were comparable to those considered protective in children who have received 3 standard vaccine doses.
Conclusions
For some products, the mean antibody concentrations induced for some pneumococcal serotypes increased with increasing doses of the polysaccharide but the functional significance of these is uncertain.
MODELLING POST-PCV13 SEROTYPE-SPECIFIC ANTI-CAPSULAR AND ANTI-PROTEIN IGG RESPONSES IN BLANTYRE, MALAWI. (ID 989)
- Jose Lourenço, United Kingdom
- Todd D. Swarthout, Malawi
- Mahan Ghafari,
- James Meiring, United Kingdom
- Andrea Gori, United Kingdom
- Uri Obolski, Israel
- Deus Thindwa, United Kingdom
- Comfort Brown, Malawi
- Maurice Mbewe, Malawi
- Melita Gordon, Malawi
- David Goldblatt, United Kingdom
- Neil French, United Kingdom
- Sunetra Gupta, United Kingdom
- Robert S. Heyderman, United Kingdom
STREPTOCOCCUS PNEUMONIAE VACCINE SEROTYPES ACQUIRE PENICILLIN BINDING PROTEIN GENE MOSAICS FROM STREPTOCOCCUS MITIS (ID 428)
- Akuzike Kalizang'oma, United Kingdom
- Chrispin Chaguza, United Kingdom
- Andrea Gori, United Kingdom
- Charlotte Davison, United Kingdom
- Sandra Beleza, United Kingdom
- Martin Antonio, Gambia
- Bernard Beall, United States of America
- David Goldblatt, United Kingdom
- Brenda Kwambana-Adams, United Kingdom
- Stephen D. Bentley, United Kingdom
- Robert S. Heyderman, United Kingdom