CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

need for any respiratory support (11.6% vs 27.7%; p<.001) and ICU admission (5.4% vs 17.1%; p<.001) were less frequent among IC (Panel-A). In multivariable analyses, IC were less likely to have severe COVID-19 compared to non-IC (aRR=0.33 [95%CI:0.20-0.50]). Subcategories of immunocompromise, such as immunodeficiency (aRR=0.44 [95%CI:0.29-0.69]) and immunosuppression (aRR=0.28 [95%CI:0.15-0.51]) were individually also associated with a reduced likelihood of severe COVID-19. Compared to children with comorbidities other than immunocompromise, IC were also less likely to have severe COVID-19 (aRR=0.23 [95%CI:0.15-0.35]) (Panel-B). Conclusion: Lower risk of severe COVID-19 was observed in hospitalized IC compared to non-IC and to those with other comorbidities, potentially in part due to lower thresholds for hospital admission for IC. Population-based studies are needed to confirm these findings.

(IR) and 95% CI was condidered within ten days after a positive NPS per 10,000 person days. Results: In total, 26,606 children with active follow-up and at least one COVID-19 NPS within the study period were included in the study analysis. Overall, 23,858 were HC, 2,527 non-IC, and 221 IC. Compared to HC, we observed the same risk of SARS-CoV-2 primary infection in IC (aHR = 0.92 [95% CI: 0.57-1.48]) and non-IC (aHR = 1.05 [95% CI: 0.91-1.21]) (Figure). Among 14,968 children with a positive NPS, IC had a higher IR of being hospitalized (IR = 4.97 [95% CI:0.99-8.94]) compared to non-IC (IR = 2.72 [95% CI:1.88-3.57]) and to HC (IR = 2.03 [95% CI:1.79-2.27]) (Figure). IC (aHR = 1.32 [95% CI:1.08-1.62]) and non-IC (aHR = 1.17 [95% CI:1.09-1.25]) were more likely to be vaccinated against COVID-19 than HC (Figure). Conclusion: Similar SARS-CoV-2 infection likelihood and higher incidence of hospitalization were observed in IC compared to HC. Greater hospitalization rates in IC may be partly due to lower thresholds for hospital admission for these patients. Hospital-setting surveillance studies evaluating additional outcomes of severity, including intensive care admission and death, are needed to confirm our findings.

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In-Hospital Mortality During Different SARS-CoV-2 Variant Waves in the EuCARE Multinational Cohort Pontus Hedberg 1 , Milosz Parczewski 2 , Giulia Marchetti 3 , Björn Jensen 4 , Francis Drobniewski 5 , Daniel Naumovas 6 , Francesca Ceccherini-Silberstein 7 , Gibran Horemheb Rubio Quintanares 8 , Matilu Mwau 9 , Cristina Toscano 10 , Maurizio Zazzi 11 , Alessandro Cozzi-Lepri 12 , Anders Sönnerborg 1 , Pontus Nauclér 1 , for EuCARE WP 3 1 Karolinska Institute, Stockholm, Sweden, 2 Pomeranian Medical University, Szczecin, Poland, 3 University of Milano–Bicocca, Milan, Italy, 4 Heinrich Heine University Düsseldorf, Düsseldorf, Germany, 5 Imperial College London, London, United Kingdom, 6 Vilnius University, Vilnius, Lithuania, 7 University of Rome Tor Vergata, Rome, Italy, 8 Paul Ehrlich Institut, Langen, Germany, 9 Kenya Medical Research Institute, Kilifi, Kenya, 10 Centro Hospitalar de Lisboa Ocidental, Lisbon, Portugal, 11 University of Siena, Siena, Italy, 12 University College London, London, United Kingdom Background: Investigating outcomes of patients hospitalized with COVID-19 throughout the pandemic is crucial to understand the effects of SARS-CoV-2 variants, previous immunity, and healthcare interventions. We compared 28-day in-hospital mortality in adults hospitalized with COVID-19 caused by Wild-type, Alpha, Delta, or Omicron variants. Whether the difference in risk by variant might vary by age was also evaluated. Methods: We conducted a multinational cohort study including patients hospitalized with COVID-19 from 9 countries (EuCARE hospitalized study). Patients >18 years, hospitalized any time from 2020-02-01 to 2022-10-15 with a SARS-CoV-2 positive test were included. Variant was classified based on sequenced viruses (if available) or from national public metadata. In-hospital mortality was compared using the cumulative incidence (CI) function and Fine Gray sub-distribution hazard models adjusted for age, sex, and comorbidities which are risk factors for severe COVID-19. Results were shown age-stratified since there was evidence that age was an effect measure modifier. Results: We included 38,585 SARS CoV-2 infected hospitalized patients (16,754 females and 21,831 males): 19,763 Wild-type, 6,387 Alpha, 3,640 Delta, and 8,795 Omicron. For in-hospital mortality, an interaction between age group and variant was observed (P=0.03), driven by the youngest group for whom smaller differences in mortality risk by variant were seen (Figure). In the older groups, the largest differences were observed between Omicron and the other variants. Among patients aged >70 years, the aSHR for Delta vs. Omicron was 2.06 (95% confidence interval 1.75-2.43). This estimate was 2.72 (2.38-3.12) for Alpha vs. Omicron, and 2.94 (2.64-3.27) for Wild-type vs. Omicron. Among unvaccinated patients, the aSHR was 1.33 (1.03-1.74) for Delta vs. Omicron, 1.61 (1.32-1.98) for Alpha vs. Omicron, and 1.69 (1.42-2.02) for Wild-type vs. Omicron. When comparing Omicron sublineages, the aSHR for the BA.1 sublineage was 2.04 (154-2.70) compared to the BA.2 sublineage and 1.71 (1.26-2.31) compared to the BA.5 sublineage.

Poster Abstracts

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Epidemiology, Clinical Features, and Severity of COVID-19 in Immunocompromised Children in Canada Costanza Di Chiara 1 , Tilmann Schober 2 , Daniel S. Farrar 1 , Julie A. Bettinger 3 , Joanne E. Embree 4 , Scott A. Halperin 5 , Tajdin Jadavji 6 , Kescha Kazmi 1 , Rupeena Purewal 7 , Manish Sadarangani 3 , Laura Sauvé 3 , Karina A. Top 5 , Fatima Kakkar 8 , Jesse Papenburg 2 , Shaun K. Morris 1 1 Hospital for Sick Children, Toronto, Canada, 2 McGill University, Montreal, Canada, 3 University of British Columbia, Vancouver, Canada, 4 University of Manitoba, Winnipeg, Canada, 5 Dalhousie University, Halifax, Canada, 6 University of Calgary, Calgary, Canada, 7 Jim Pattison Children’s Hospital, Saskatoon, Canada, 8 Centre Hospitalier Universitaire Sainte-Justine, Montreal, Canada Background: The impact of immunocompromised states on pediatric COVID-19 and outcomes remains unclear. We aimed to evaluate clinical features and severity of SARS-CoV-2 infection in hospitalized children with and without immunocompromising conditions. Methods: We conducted a national surveillance study of children <17 years hospitalized for COVID-19 from April 2020–May 2022. Data were captured through two surveillance programs The Canadian Pediatric Surveillance Program and the Canadian Immunization Monitoring Program, ACTive which covers ~90% of all Canadian tertiary-care pediatric beds. Incidental SARS-CoV-2 positive cases were excluded. Immunocompromised children (IC) were defined as those with an immunocompromising condition and/ or on immunosuppressive treatment(s). Severe COVID-19 was defined as a requirement for intensive care unit (ICU) admission, ventilator or hemodynamic support, organ system complications (neurologic, cardiac, and respiratory), or death. Adjusted risk ratios (aRR) for severe COVID-19 among IC versus non-IC were calculated using robust Poisson regression, adjusted for age, sex, non-IC comorbidities, lineage, and vaccination status. Results: Overall, 1874 children were hospitalized with COVID-19, of which 224 (12%) were IC. IC were older (median age 7 years [interquartile range (IQR) 3.6–12.0] than non-IC (1.3 years [IQR 0.3–2.9] years; p<.001) and had fewer comorbidities other than immunocompromise (31.7% vs 39.6%; p=.02). A lower frequency of respiratory distress was observed in IC compared to non-IC (17.9% vs 41.6%; p<.001). Severe COVID-19 (9.8% vs 28.4%; p<.001), as well as the

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