Sharing a household with children and risk of COVID-19: a study of over 300 000 adults living in healthcare worker households in Scotland

Abstract

ObjectiveChildren are relatively protected from COVID-19, due to a range of potential mechanisms. We investigated if contact with children also affords adults a degree of protection from COVID-19.DesignCohort study based on linked administrative data.SettingScotland.Study populationAll National Health Service Scotland healthcare workers and their household contacts as of March 2020.Main exposureNumber of young children (0–11 years) living in the participant’s household.Main outcomesCOVID-19 requiring hospitalisation, and any COVID-19 (any positive test for SARS-CoV-2) in adults aged ≥18 years between 1 March and 12 October 2020.Results241 266, 41 198, 23 783 and 3850 adults shared a household with 0, 1, 2 and 3 or more young children, respectively. Over the study period, the risk of COVID-19 requiring hospitalisation was reduced progressively with increasing numbers of household children—fully adjusted HR (aHR) 0.93 per child (95% CI 0.79 to 1.10). The risk of any COVID-19 was similarly reduced, with the association being statistically significant (aHR per child 0.93; 95% CI 0.88 to 0.98). After schools reopened to all children in August 2020, no association was seen between exposure to young children and risk of any COVID-19 (aHR per child 1.03; 95% CI 0.92 to 1.14).ConclusionBetween March and October 2020, living with young children was associated with an attenuated risk of any COVID-19 and COVID-19 requiring hospitalisation among adults living in healthcare worker households. There was no evidence that living with young children increased adults’ risk of COVID-19, including during the period after schools reopened.

The Type I interferon antiviral gene program is impaired by lockdown and preserved by caregiving

“…The present results suggest a psychobiological mechanism for the observation that parents and others who cohabitate with children show reduced vulnerability to some viral diseases (65)(66)(67)(68). Studies have documented reduced risk of COVID-19 (but not SARS-CoV-2 exposure/infection) among adults living in households with children (65)(66)(67).…”

“…The present results suggest a psychobiological mechanism for the observation that parents and others who cohabitate with children show reduced vulnerability to some viral diseases (65)(66)(67)(68). Studies have documented reduced risk of COVID-19 (but not SARS-CoV-2 exposure/infection) among adults living in households with children (65)(66)(67). These effects have been interpreted as stemming from immune shielding (i.e., children's robust antiviral responses reduce the intensity of viral transmission to household adults and thereby reduce the incidence of symptomatic disease).…”

Infant Feeding Type of Children Who Qualify For SARS-CoV-2 Testing: An Observational Study.

“…With regards to the household characteristics, Woods et al have recently reported that living with children was associated with an attenuated risk of any COVID-19 among adults in the household [10]. Given that we report that households with never breastfed children were more likely to include more children under 15, the higher rate of COVID-19 among never breastfed children in our sample is not likely to be associated to their speci c indoor exposures.…”

Description and analysis of representative COVID-19 cases–A retrospective cohort study

“…Even though our correlation was not statistically significant, a recent publication observed similar findings. In a cohort study from Scotland among 300,000 adults living in a household, the risk of testing positive for SARS-CoV-2 was slightly lower for individuals living with young children after adjusting for potential confounders [38]. However, large data sets from other countries need to be analyzed to address this with more sincerity as these findings could be of importance for informing policy on school openings.…”