Association Between Risk of COVID-19 Infection in Nonimmune Individuals and COVID-19 Immunity in Their Family Members.

ABSTRACT:

Importance

The association between COVID-19 immunity within families and the risk of infection in nonimmune family members is unknown.

Objective

To investigate the association between risk of COVID-19 in nonimmune individuals and the number of their family members with known immunity acquired from a previous COVID-19 infection or full vaccination (2 vaccine doses).

Design, setting, and participants

In this cohort study of data from nationwide registries in Sweden, all individuals who acquired immunity from either previous COVID-19 infection or full vaccination until May 26, 2021, were considered for inclusion. Each person with immunity was matched 1:1 to an individual without immunity from an identified cohort of individuals with families comprising 2 to 5 members.

SUBMITTER: Nordstrom P 

PROVIDER: S-EPMC8506298 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature