Vassiliki Spoulou (Greece)
"Agia Sophia" Children's Hospital First Department of PediatricsAuthor Of 2 Presentations
CHARACTERISTICS OF CHILDREN HOSPITALIZED WITH MIS-C DURING THREE PANDEMIC WAVES IN GREECE
Abstract
Backgrounds:
The Multisystem Inflammatory Syndrome in Children (MIS-C) is a rare but potentially severe complication of COVID-19.
Methods
This is a retrospective observational study of children aged <18 years hospitalized with MIS-C in 10 tertiary hospitals in Greece during three pandemic waves characterized by different SARS-CoV-2 variant: i. from August 2020 to January 2021 (EU1-B.1.177), ii. from February 2021 to July 2021 (Alpha-B.1.1.7) and iii. from August 2021 to December 2021 (Delta-B.1.617.2). The aim of the study was to document the incidence over time, clinical characteristics and outcome of children admitted with MIS-C in Greek hospitals during the COVID-19 pandemic.
Results:
In total, 119 patients were included, 91.6% (109/119) met the WHO criteria of MIS-C diagnosis: 26.9% (32/119), 39.5% (47/119) and 33.6% (40/119) were hospitalized during the 1st, 2nd, and 3rd study period, respectively. Demographic and clinical characteristics are shown in Table 1. No cases were found before October 2020. The incidence of MIS-C significantly decreased over the three waves from 3.3/1000 to 0.25/1000 confirmed COVID-19 cases (P <0.0001). No other significant difference was observed in the clinical manifestations and disease severity of children hospitalized with MIS-C over the three waves.
Conclusions/Learning Points:
This study indicates that the incidence of MIS-C may vary according to the predominant variant. Outcome remains favourable regardless of the variant leading to MIS-C. Larger studies are needed to clarify if clinical characteristics and/or disease severity may differ, as well.
EVALUATION OF PROTECTIVE EFFICACY AND IMMUNOGENICITY OF EPITOPE-BASED PNEUMOCOCCAL VACCINE CANDIDATES USING SYNTHETIC VIRUS-LIKE PARTICLES (SVLPS) IN AN INTRAPERITONEAL SEPSIS MURINE MODEL
Abstract
Backgrounds:
We have previously identified 4 immunoreactive, linear B-cell epitopes within pneumococcal surface proteins (CbpD, PhtD, PhtE & ZmpB) that are highly conserved among different serotypes. These epitopes, emulsified in Freund’s Adjuvant, showed high immunogenicity and offered prolonged survival against murine pneumococcal sepsis. Herein, they were incorporated in SVLPs to improve survival rates and induce robust humoral immune responses without the need for external adjuvants.
Methods
Female BALB/c mice were subcutaneously immunized thrice at three-week intervals with synthetic 20mer peptides displayed on the surface of SVLPs. Positive controls received PCV13, while negative controls received the SVLP-carrier alone. Pneumococcal lethal sepsis was induced by 106 CFUs of an intraperitoneally administered serotype 3 clinical strain and survival was monitored. Sera were collected one day prior the second and third immunization and before the pneumococcal challenge. Antibody responses were assessed using ELISA.
Results:
Mice actively immunized with SVLP-conjugated synthetic peptides demonstrated enhanced survival against pneumococcal sepsis, compared to controls (p=0.005-0.04, Wilcoxon test). Five days after infection the survival rate was 100% for the positive control (PCV13), 66.7% for PhtE, 33.3% for CbpD, 16.7% for ZmpB and 0% for PhtD and the negative control (SVLPs), respectively. All immunized mice produced high levels of peptide-specific IgG antibodies. The difference in the endpoint titers, compared to controls, was statistically significant (p=0.0001-0.03, unpaired t-test). All immunized mice elicited gradually higher antibody titers upon receiving the booster immunizations.
Conclusions/Learning Points:
SVLP-conjugated synthetic epitopes are able to confer prolonged survival, compared to controls, associated with robust humoral immune responses. Further experiments are needed to assess the protective efficacy of the epitopes with the most promising characteristics in order for them to be considered as candidate antigens for novel pneumococcal vaccine formulations.
Poster Author Of 8 e-Posters
EP437 - SARS-COV-2 RBD-SPECIFIC MEMORY B CELL RESPONSES INDUCED BY THE BNT162B2 MRNA VACCINE IN HEALTHY ADULTS (ID 1449)
EP461 - COMPARATIVE CHARACTERIZATION OF HUMAN ANTIBODY RESPONSE INDUCED BY BNT162B2 VACCINE VS WILD-TYPE INFECTION (ID 708)
EP462 - PAVING THE WAY TOWARDS PRECISION VACCINOLOGY: THE PARADIGM OF MYOCARDITIS AFTER COVID-19 VACCINATION (ID 1426)
EP490 - COMPARISON OF ACUTE PNEUMONIA CAUSED BY SARS-COV-2 AND INFLUENZA A IN CHILDREN: A RETROSPECTIVE COHORT STUDY (ID 1439)
EP581 - CELLULAR AND HUMORAL ANAMNESTIC IMMUNE RESPONSES TO 13-VALENT PNEUMOCOCCAL CONJUGATE VACCINE (PCV13) IN CHILDREN WITH IDIOPATHIC NEPHROTIC SYNDROME (INS) (ID 746)
PD055 - A SYSTEMS VACCINOLOGY APPROACH OF THE BNT162B2 MRNA VACCINE RESPONSE: RESULTS OF A PILOT STUDY IN HEALTH CARE PROFESSIONALS (ID 1521)
PD161 - SEROPREVALENCE OF SARS-COV-2 INFECTION AMONG CHILDREN AND THEIR PARENTS IN GREECE (ID 786)
- Dimitra Dimopoulou (Greece)
- Maria Kyritsi (Greece)
- Eleni Vergadi (Greece)
- Ekaterini Tsiligianni (Greece)
- Eleni Papadimitriou (Greece)
- Artemis Mavridi (Greece)
- Spyridon Giannakopoulos (Greece)
- Georgia Tsiourvopoulou (Greece)
- Maria Palyvou (Greece)
- Evangelia Angeli (Greece)
- Nikitas Brikos (Greece)
- IRINI ELEFTHERIOU (Greece)
- Nikos SPYRIDIS (Greece)
- Athanasios Michos (Greece)
- Vassiliki Spoulou (Greece)
- Despoina Gkentzi (Greece)
- Ekaterini Siomou (Greece)
- Vassiliki Papaevangelou (Greece)
- George A. Syrogiannopoulos (Greece)
- Emmanouil Galanakis (Greece)
- Christos Hadjichristodoulou (Greece)
- Maria Tsolia (Greece)
PD168 - MULTISYSTEM INFLAMMATORY SYNDROME IN CHILDREN (MIS-C): A NATIONWIDE COLLABORATIVE STUDY IN THE GREEK POPULATION (ID 774)
- STAVROULA LAMPIDI (Greece)
- Despoina Maritsi (Greece)
- IRINI ELEFTHERIOU (Greece)
- Evaggelia Farmaki (Greece)
- Nikos SPYRIDIS (Greece)
- KONSTANTINA CHARISI (Greece)
- Petrina Vantsi (Greece)
- Filippos G. Filippatos (Greece)
- Kleopatra Skourti (Greece)
- EFIMIA PAPADOPOULOU-ALATAKI (Greece)
- Kyriaki Papadopoulou-Legbelou (Greece)
- Parthena Kampouridou (Greece)
- Ioanna N. Grivea (Greece)
- Eleni Vergadi (Greece)
- Despoina Gkentzi (Greece)
- Despina Dimou (Greece)
- Patra Koletsi (Greece)
- Lampros Fotis (Greece)
- Vassiliki Papaevangelou (Greece)
- Gabriel Dimitriou (Greece)
- Emmanouil Galanakis (Greece)
- George A. Syrogiannopoulos (Greece)
- Vassiliki Spoulou (Greece)
- Athanasios Michos (Greece)
- Emmanuel Roilides (Greece)
- Maria Tsolia (Greece)