Maria D. Knoll, United States of America

International Vaccine Access Center (IVAC) Department of International Health, Johns Hopkins Bloomberg School of Public Health;

Author Of 12 Presentations

 Conference Calendar

CONSISTENCY OF VACCINATION HISTORIES OBTAINED FROM MEDICAL RECORDS OR CAREGIVER RECALL IN NEPAL. (ID 1135)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

Abstract

Background

PCV status, necessary for assessing vaccine impact, is often incomplete or unknown. For children admitted with pneumonia in Kathmandu, Nepal, we compared vaccine histories from caregivers vs medical records to determine if these provided similar estimates of coverage.

Methods

Between 2016-2019, patients aged 6 months to 14 years admitted with pneumonia at Patan Hospital, enrolled into a pneumococcal carriage study had their number of PCV doses collected by caregiver recall and/or from hospital medical records. Records, created at birth, are updated when they receive routine vaccinations there; for vaccinations administered elsewhere, vaccine history is obtained from caregivers during any hospital admission. Cases were excluded from analyses if both caregiver recall and medical records were cited as the source.

Results

Of the 1,603 inpatients enrolled, 1,201 (80%) had data from either caregiver recall or medical records. PCV coverage (3 doses) was higher for caregiver recall than medical records (43% vs 35%; p=0.03), while Hib vaccine coverage was similar (91% vs 87%; p=0.16).

Conclusions

Although caregiver recall provided statistically higher estimates of vaccine coverage than medical records, the estimates were generally similar. Medical records may be incomplete (underestimate) and caregiver recall may have recall bias (overestimate); the truth may be in between.

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PNEUMOCOCCAL CARRIAGE PRE- AND POST- PCV: A SYSTEMATIC REVIEW (ID 431)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

ANTIMICROBIAL SUSCEPTIBILITY PROFILE AND SEROTYPE DISTRIBUTION OF PNEUMOCOCCAL BLOOD CULTURE ISOLATES FROM NEPALESE CHILDREN (ID 672)

Session Name
Basic Sciences - Conventional and Molecular Microbiology
Presenter
Authors

PCV INTERCHANGEABILITY: SYNTHESIZING AVAILABLE EVIDENCE TO INFORM PROGRAM SWITCHES BETWEEN PRODUCTS IN AN EXPANDING VACCINE PRODUCT LANDSCAPE (ID 1226)

Session Name
Population Sciences - Knowledge Translation and Public Health Policy
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Authors

IMPACT OF PNEUMOCOCCAL CONJUGATE VACCINE (PCV-10) ON RADIOLOGICAL PNEUMONIA AT A TERTIARY CARE CENTRE IN NEPAL (ID 514)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

Abstract

Background

Routine immunization with 10-valent pneumococcal conjugate vaccine (PCV10) was introduced in Kathmandu in 2015 with doses administered at 6 weeks, 10 weeks and 9 months of age. We assessed the impact of PCV10 on the prevalence of radiographic changes in children aged 2 months to 14 years with a clinical diagnosis of pneumonia admitted to Patan Hospital, Kathmandu.

Methods

Digitalized chest radiographs were interpreted using standardized WHO criteria as primary endpoint pneumonia (PEP), other infiltrate or normal, by two specific readers. A third reader arbitrated upon all discordant results.

Results

From March 2014 to December 2018, 1755 children were enrolled, of whom 1692 (96%) had interpretable radiographs. The proportion of children with PEP decreased annually from 84/189 (44%) in 2014 to 105/414 (25%) in 2018 (p<0.001). PEP was associated with age, occurring in 247/1090 (22%) children <2 years of age, in comparison with 120/175 (69%) children ≥5 years of age (p<0.001), and carriage of PCV10 serotypes, occurring in 95/188 (51%) children with PCV10 carriage in comparison with 459/1504 (31%) children with non-PCV10 serotypes or no carriage (p<0.001).

Conclusions

The prevalence of PEP in children hospitalized with pneumonia decreased from 2014 to 2018 in association with the implementation of PCV10 immunization in Kathmandu.

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CHILDREN ADMITTED TO HOSPITAL WITH LOWER-CHEST-WALL INDRAWING PNEUMONIA IN SEVEN LOW AND MIDDLE-INCOME COUNTRIES: WHO DIED AND WHO SURVIVED? (ID 758)

Session Name
Clinical Sciences - Treatment of Pneumococcal Disease in Infants, Children/Youth, and Adults
Presenter
Authors

Abstract

Background

In 2013, to increase effective distribution of antibiotics, WHO revised treatment guidelines for childhood pneumonia with lower chest wall indrawing (LCWI) to recommend home-based-treatment with oral antibiotics rather than hospital-based management. We analysed the implications of this policy in the PERCH study, where all children were hospitalised.

Methods

In PERCH, 2113 children aged 2-59 months were admitted with LCWI pneumonia between 2011-2014 in Kenya, Zambia, South Africa, Mali, The Gambia, Bangladesh and Thailand. We analysed their mortality risk, and risk factors for mortality using logistic regression.

Results

Among cases with LCWI pneumonia, 76 (3.6%) died in hospital or within 7 days of discharge. Factors associated with fatal outcome included age (aOR 2.03 (95%CI 1.05-3.93) for infants vs older children), absence of cough, oxygen saturation (80-91% oxygen aOR 2.04 (1.07-3.90), <80% aOR 6.51 (2.82-15.0)), low anthropometric scores and HIV exposure.

Conclusions

Despite hospital admission, 3.6% of children with LCWI pneumonia died; mortality may be higher among similar children if treated in the community. Among children with LCWI pneumonia presenting to hospital, selective admission for those who also have hypoxia, features of malnutrition and young age may ensure that those with the greatest risk of death receive optimal supportive therapy.

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IMPACT OF PCV10 IN NEPAL ON NASOPHARYNGEAL CARRIAGE OF PNEUMOCOCCUS IN YOUNG INFANTS PRIOR TO THEIR VACCINATION (ID 530)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

DOES VIRAL DETECTION IN THE NASOPHARYNX IMPACT THE DISTRIBUTION OF COLONISING PNEUMOCOCCAL SEROTYPES OBSERVED IN PNEUMONIA CASES AMONG NEPALESE CHILDREN? (ID 799)

Session Name
Basic Sciences - Interaction with Microbiome, Viruses, other Bacteria
Presenter
Authors

IMPACT OF THE INTRODUCTION OF THE PNEUMOCOCCAL CONJUGATE VACCINE ON PAEDIATRIC PNEUMONIA CASES IN NEPAL (ID 543)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

MONITORING VACCINE IMPACT ON COMMUNITY CARRIAGE IN NEPAL REVEALS CHANGES IN THE CIRCULATING POPULATION OF PNEUMOCOCCAL SEROTYPES AND ANTIMICROBIAL RESISTANCE GENES (ID 977)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement
Presenter
Authors

Abstract

Background

Community carriage of pneumococcal serotypes in children was assessed pre- and post-PCV10 introduction in Nepal to monitor pneumococcal vaccine impact. Molecular serotyping by microarray enabled detection of multiple-serotype carriage plus non-encapsulated pneumococcal lineages, related Streptococcus species and selected antimicrobial resistance genes.

Methods

Nasopharyngeal swabs were collected from healthy Nepalese children in 2014-15 (pre-PCV10) and 2017-18 (post-PCV10). DNA was extracted from plate sweeps of 1,241 and 1,445 swab cultures for pre- and post-vaccine periods respectively and analysed by Senti-SP molecular serotyping microarray.

Results

Comparing carriage among children pre- and post-PCV10, there was a decrease in PCV10 serotype carriage (37% vs 17%) and an increase in non-vaccine serotype carriage (67% vs 73%). There was no change for non-encapsulated pneumococcal lineages (16% vs 16%), an increase in related Streptococcal species (22% vs 25%) and an increase in detection of antimicrobial resistance genes (65% vs 74%). Multiple pneumococcal serotype carriage decreased (24% vs 16%) and multiple carriage including non-encapsulated pneumococci and related Streptococcal species also decreased (45% vs 41%).

Conclusions

Introduction of PCV10 in Nepal has resulted in a decrease in vaccine type carriage within two years. However, increases in carriage of non-vaccine types as well as antimicrobial resistance genes and related Streptococcal species were observed.

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DETECTION OF NASOPHARYNGEAL VIRUSES IN PAEDIATRIC INPATIENT PNEUMONIA CASES BEFORE AND AFTER THE INTRODUCTION OF PCV10 VACCINE IN NEPAL (ID 329)

Session Name
Basic Sciences - Interaction with Microbiome, Viruses, other Bacteria
Presenter
Authors

COMPARISON OF IMMUNOGENICITY OF TEN- AND THIRTEEN-VALENT PNEUMOCOCCAL CONJUGATE VACCINES – A SYSTEMATIC REVIEW AND NETWORK META-ANALYSIS (ID 567)

Session Name
Population Sciences - Epidemiology, Economics, and Mathematical Modelling
Presenter
Authors

Abstract

Background

Streptococcus pneumoniae causes substantial morbidity and mortality globally, with serotype-specific disease burden varying geographically. Currently there are two widely used pneumococcal conjugate vaccines (PCV). Evidence is limited regarding their comparative serotype-specific immunogenicity and efficacy.

Methods

We conducted a systematic-review and network meta-analysis of studies in which the immunogenicity of PCVs was directly compared in head-to-head randomised trials. Network meta-analysis incorporates both direct pair-wise comparisons and indirect comparisons (e.g. PCV10 vs PCV7, and PCV13 vs PCV7) thereby increasing overall statistical precision for the main comparison of interest (PCV10 vs PCV13). The difference in immunogenicity, as measured by geometric mean ratio (GMR), was examined by serotype.

Results

27 trials were included in the network meta-analysis, 4 directly comparing PCV10 and PCV13, 7 comparing PCV7 and PCV10, and 16 comparing PCV7 and PCV13. For the 10 common serotypes, immunogenicity at 1 month after the primary vaccination series was higher for PCV13 for 7 serotypes, with GMRs ranging from 1.18 to 2.50. In contrast, serotype 5, 18C and 19F favoured PCV10. Similar results were observed post-booster dose except for serotype 5 and 7F.

Conclusions

Variation in serotype-specific immunogenicity exists between PCV10 and PCV13, indicating that further investigation into whether this translates to heterogeneity in protection is needed.

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