1097. Risk of Severe COVID-19 Disease in Individuals with Down syndrome: a Matched Cohort Study from a Large, Integrated Health Care System
Authors: Ku Jennifer H , Levin Myron J , Luo Yi , Florea Ana , Lin I Chun , Tian Yun , Tseng Hung Fu 
Published: December 2022

Background

Down syndrome (DS) is associated with an increased risk of infections attributed to immune defects. Whether individuals with DS are at an increased risk of severe COVID-19 remains unclear.

Methods

In a matched cohort study, we evaluated the risk of COVID-19 infection and severe COVID-19 disease in individuals with DS and their matched counterparts in a pre-COVID-19 vaccination period at Kaiser Permanente Southern California. Multivariable Cox proportion hazard regression was used to investigate associations between DS and risk of COVID-19 infection and severe COVID-19 disease.

Results

Our cohort included 2,541 individuals with DS and 10,164 without DS matched on age, sex, and race/ethnicity (51.6% female, 53.3% Hispanic, median age 25 years [interquartile range 14 – 38]), with pulmonary disease as the most common comorbidity (13.1%) followed by diabetes (5.4%). While the rate of COVID-19 infection in individuals with DS was 32% lower than their matched counterparts (adjusted hazard ratio [aHR] 0.68, 95% CI: 0.56-0.83), the rate of severe COVID-19 disease was 6-fold higher (aHR 6.14, 95% CI: 1.87-20.16) (Table 1). The Kaplan-Meier plot demonstrated similar cumulative incidence for those with and without DS at the beginning of the pandemic, followed by a rate increase in July 2020 (at 4 months of follow-up), and in November 2020 (at 8 months of follow-up) (Figure 1), after which the cumulative incidence for those with DS was consistently higher. Figure 2 demonstrated consistently higher cumulative incidence estimates of COVID-19 hospitalization for those with DS than those without. Table 1.Incidence rates and hazard ratios of COVID-19 infection, severe COVID-19 disease and COVID-19 hospitalization mortality among 2,541 individuals with Down Syndrome and 10,164 matched counterparts without Down Syndrome at Kaiser Permanente Southern California, 03/01/2020 - 12/31/2020

aAdjusted for covariates: body mass index, smoking, number of outpatient visits, number of emergency department visits, number of hospitalizations, frailty status based on frailty index (yes/no), all baseline comorbidities, and medical center area.

Abbreviations: DS = Down Syndrome; non-DS = matched counterparts without Down Syndrome; CI = confidence interval Figure 1.Cumulative incidence estimates of COVID-19 infection by Down syndrome status, Kaiser Permanente Southern California, 03/01/2020 - 12/31/2020Figure 2.Cumulative incidence estimates of COVID-19 hospitalization by Down syndrome status, Kaiser Permanente Southern California, 03/01/2020 - 12/31/2020

Conclusion

Although the risk of COVID-19 infection is lower, the risk of severe disease is higher in individuals with DS compared to their matched counterparts. Better infection monitoring, early treatment, and promotion of vaccine for COVID-19 are warranted for DS populations.

Disclosures

Jennifer H. Ku, PhD MPH, GSK: Grant/Research Support|Moderna: Grant/Research Support Myron J. Levin, MD, Curevo: Advisor/Consultant|Merck: Advisor/Consultant|Pfizer: Advisor/Consultant|seqirus: Advisor/Consultant|SmithKline Beecham: Grant/Research Support Yi Luo, PhD, Glaxosmithkline: Grant/Research Support|Moderna: Grant/Research Support|Pfizer: Grant/Research Support|Seqirus: Grant/Research Support Ana Florea, PhD MPH, Gilead: Grant/Research Support|GSK: Grant/Research Support|Moderna: Grant/Research Support|Pfizer: Grant/Research Support Yun Tian, MS, Glaxosmithkline: Grant/Research Support|Moderna: Grant/Research Support Hung Fu Tseng, PhD MPH, GSK: Grant/Research Support|Janssen: Advisor/Consultant|Moderna: Grant/Research Support|Pfizer: Advisor/Consultant|Seqirus: Grant/Research Support.