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. 2022 Mar 1;74(4):703-706.
doi: 10.1093/cid/ciab496.

Increased Household Secondary Attacks Rates With Variant of Concern Severe Acute Respiratory Syndrome Coronavirus 2 Index Cases

Sarah A Buchan  1   2 , Semra Tibebu  1 , Nick Daneman  1   3   4   5   6 , Michael Whelan  1 , Thuva Vanniyasingam  7 , Michelle Murti  1   2 , Kevin A Brown  1   2
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Increased Household Secondary Attacks Rates With Variant of Concern Severe Acute Respiratory Syndrome Coronavirus 2 Index Cases

Sarah A Buchan et al. Clin Infect Dis. .

Abstract

We compared secondary attack rates in households with B.1.1.7 variant of concern (VOC) versus non-VOC index cases in a matched cohort in Ontario, Canada. The secondary attack rate for VOC index cases was 1.31 times higher than non-VOC index cases. This increase was particularly accentuated for asymptomatic or presymptomatic index cases.

Keywords: COVID-19; SARS-CoV-2; household; transmission; variants of concern.

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Figures

Figure 1.
Figure 1.
Risk ratio comparing household secondary attack rate associated with VOC vs. non-VOC index cases by characteristic of index case, unadjusted (formula image) and adjusted by 1:1 propensity-score matching (formula image) estimates. Unadjusted risk ratio accounts for household clustering and includes the full cohort. Adjusted risk ratio refers to the propensity score-matched cohort. Abbreviations: CI, confidence interval; VOC, variant of concern.
See this image and copyright information in PMC

References

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