ABSTRACT
Background: The effect of vaccination for COVID-19 on onward transmission is unknown. Methods: A national record linkage study determined documented COVID-19 cases and hospitalizations in unvaccinated household members of vaccinated and unvaccinated healthcare workers from 8th December 2020 to 3rd March 2021. The primary endpoint was COVID-19 >= 14 days following the first dose. Results: The cohort comprised of 194,362 household members (mean age 31.1 years) and 144,525 healthcare workers (mean age 44.4 years). 113,253 (78.3%) of healthcare workers received at least one dose of the BNT162b2 mRNA or ChAdOx1 nCoV-19 vaccine and 36,227 (25.1%) received a second dose. Household members of vaccinated healthcare workers had a lower risk of COVID-19 case compared to household members of unvaccinated healthcare worker (rate per 100 person-years 9.40 versus 5.93; HR 0.70, 95% confidence interval [CI] 0.63-0.78). The effect size for COVID-19 hospitalization was similar, with the confidence interval crossing the null (HR 0.77 [0.53-1.10]). The rate per 100 person years was lower in vaccinated compared to unvaccinated healthcare workers for documented (20.13 versus 8.51; HR 0.45 [0.42-0.49]) and hospitalized COVID-19 (0.97 versus 0.14; HR 0.16 [0.09-0.27]). Compared to the period before the first dose, the risk of documented COVID-19 case was lower at >= 14 days after the second dose for household members (HR 0.46 [0.30-0.70]) and healthcare workers (HR 0.08 [0.04-0.17]). Conclusion: Vaccination of health care workers was associated with a substantial reduction in COVID-19 cases in household contacts consistent with an effect of vaccination on transmission.
Subject(s)
COVID-19ABSTRACT
* Objectives - To investigate:(1) the risk of severe COVID-19 in those eligible for shielding, and (2) the relation of severe COVID-19 to transmission-related factors in those in shielding and the general population. * Design - Matched case-control study (REACT-SCOT). * Setting - Population of Scotland from 1 March 2020 to 28 January 2021. * Participants - All 160307 diagnosed cases of COVID-19 and 1564782 controls matched for age, sex and primary care practice, linked with all 204913 individuals identified as eligible for shielding by Public Health Scotland. * Main outcome measure - Severe COVID-19, defined as cases that entered critical care or were fatal. * Results - With those without risk conditions as reference category, the univariate rate ratio for severe COVID-19 was 5.3 (95% CI 5.0 to 5.7, p=4 x 10-527) in those with moderate risk conditions and 7.6 (95% CI 7.1 to 8.3, p=1 x 10-527) in those eligible for shielding. The highest rate was in solid organ transplant recipients: rate ratio 13.6 (95% CI 9.6 to 19.2, p=8 x 10-50). In both the shielded and the general population, the risk of severe COVID-19 increased with the number of adults but decreased with the number of school-age children in the household. Severe COVID-19 was strongly associated with recent exposure to hospital (defined as 5 to 14 days before presentation date): rate ratio 12.6 (95% CI 11.7 to 13.6, p=2 x 10-989) overall. In a case-crossover analysis with less recent exposure only (15 to 24 days before first testing positive) as reference category, the rate ratio associated with recent exposure only was 6.3 (95% CI 3.6 to 11.1, p=2 x 10-10). Among those eligible for shielding, the population attributable risk fraction (PARF) of severe cases for recent exposure to hospital was 36%. In the general population the PARF for recent exposure to hospital peaked at 46% in May 2020 and again at 64% in December 2020. * Conclusions - The effectiveness of shielding vulnerable individuals was limited by the inability to control transmission in hospital and from other adults in the household. For solid organ transplant recipients, in whom the efficacy of vaccines is uncertain, these results support a policy of offering vaccination to household contacts. Mitigating the impact of the epidemic requires control of nosocomial transmission.
Subject(s)
COVID-19ABSTRACT
Objective To determine the risk of hospitalisation with COVID-19 and severe COVID-19 among teachers and their household members, overall and compared to healthcare workers and the general working-age population. Design Population-based nested case-control study. Settings Scotland, March 2020 to January 2021. Before and after schools re-opened in early August 2020. Participants All cases of COVID-19 in Scotland in adults ages 21 to 65 (n = 83,817) and a random sample of controls matched on age, sex and general practice (n = 841,708). Exposure Individuals identified as actively teaching in a Scottish school by the General Teaching Council for Scotland, and household members of such individuals identified via the Unique Property Reference Number. Comparator Individuals identified as healthcare workers in Scotland, their household members, and the remaining "general population" of working-age adults. Main outcomes The primary outcome was hospitalisation with COVID-19 defined in anyone testing positive with COVID-19 in hospital, admitted to hospital within 28 days of a positive test, and/or diagnosed with COVID-19 on discharge from hospital. Severe COVID-19 was defined as individuals admitted to intensive care or dying within 28 days of a positive test or assigned COVID-19 as a cause of death. Results Most teachers were young (mean age 42), female (80%) and had no underlying conditions (84%). The cumulative incidence (risk) of hospitalisation with COVID-19 was below 1% for all of the working age adults. In the period after school re-opening, compared to the general population, in conditional logistic regression models adjusting for age, sex, general practice, deprivation, underlying conditions and number of adults in the household, the relative risk in teachers (among 18,479 cases and controls) for hospitalisation was rate ratio (RR) 0.97 (95%CI 0.72-1.29) and for severe COVID-19 was RR 0.27 (95%CI 0.09-0.77). Equivalent rate ratios for household members of teachers were 0.97 (95%CI 0.74-1.27) and 0.67 (95%CI 0.36-1.24), and for healthcare workers were 1.82 (95%CI 1.55-2.14) and 1.76 (95%CI 1.22-2.56), respectively. Conclusion Compared to working-age adults who are otherwise similar, teachers and their household members are not at increased risk of hospitalisation with COVID-19 and are at lower risk of severe COVID-19. These findings are broadly reassuring for adults engaged in face to face teaching
Subject(s)
COVID-19 , DeathABSTRACT
Introduction COVID-19 deaths are commoner among care-home residents, but the mortality burden has not been quantified. Methods Care-home residency was identified via a national primary care registration database linked to national mortality data. Life expectancy was estimated using Makeham-Gompertz models, to (i) describe yearly life expectancy from Nov 2015 to Oct 2020 (ii) compare life expectancy (during 2016-2018) between care-home residents and the wider Scottish population and (iii) apply care-home life expectancy estimates to COVID-19 death counts to estimate years of life lost (YLL). Results Among care-home residents, life expectancy in 2015/16 to 2019/20 ranged from 2.7 to 2.3 years for women and 2.3 to 1.8 years for men. Life expectancy was lowest in 2019/20. Age-sex specific life expectancy in 2016-2018 in care-home residents was lower than in the Scottish population (10 and 2.5 years in those aged 70 and 90 respectively). Rather than using national life tables, applying care-home specific life expectancies to COVID-19 deaths yields, mean YLLs for care-home residents were 2.6 and 2.2 for women and men respectively, with total care-home resident YLLs of 3,560 years in women and 2,046 years in men. In people aged over-70, approximately half of deaths and a quarter of YLL attributed to COVID-19 were accounted for by the 5% of over-70s who were care-home residents. Conclusion Prioritising care-home residents for vaccination is justified not only in terms of total deaths, but also in terms of years of life lost. Research in context Evidence before this study We searched PubMed to 1 st December 2020, with the terms (“nursing home” OR “care-home” OR “long-term care” OR “residential care”) AND (“mortality” OR “life expectancy” OR “length of stay”). We also searched for studies specific to the impact of the COVID-19 pandemic on those living in care-homes. We restricted our search to publications in English. Usual care-home life expectancy, in a UK context, has not previously been defined. One systematic review of length of stay was identified, which found significant heterogeneity in factors and associations. The impact of COVID-19 on excess mortality among care-home residents was noted, but the impact on life expectancy was not reported. Studies evaluating life expectancy among older people in the COVID-19 pandemic have not taken account of residency in their estimates. Added value of this study Using Scottish national representative linked data we describe the usual life expectancy of older adults (aged ≥70 years) living in care-homes, compared to older people living elsewhere. Deaths among care-home residents account for a considerable proportion of all mortality in older adults, around 19% for men and 30% for women. Life expectancy in care-home residents during the pandemic fell by almost 6 months, from 2.7 to 2.3 years in men and 2.1 to 1.8 years in women. In total, over 5,600 Years of Life were Lost (YLL) by care-home residents in Scotland who died with COVID-19. Around half of COVID-19 deaths and a quarter of YLL in those aged 70 years and over occurred among care-home residents. During the COVID-19 pandemic a smaller proportion of deaths among care-home residents occurred in hospitals. Implications of all the available evidence Prioritising the 5% of older adults who are care-home residents for vaccination against COVID-19 is justified both in terms of total deaths and total years of life lost. Individual and societal planning for care needs in older age relies on understanding usual care-home life expectancy and patterns of mortality. Understanding life expectancy may help clinicians, residents and their families make decisions about their health care, facilitating more informed discussions around their priorities and wishes. Population-wide estimates of YLL and burden of disease should take account of residency status, given the significant differences between life expectancy of those living in care-homes from their peers in other settings.
Subject(s)
COVID-19ABSTRACT
ObjectiveChildren are relatively protected from COVID-19, possibly due to cross-protective immunity. 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 NHS Scotland healthcare workers and their household contacts as of March 2020. Main exposureNumber of young children (0-11 years) living in the participants 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 3,850 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 hazard ratio (aHR) 0.93 per child (95% CI 0.79-1.10). The risk of any COVID-19 was similarly reduced, with the association being statistically significant (aHR per child 0.93; 95% CI 0.88-0.98). 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 0.92-1.14). 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 re-opened.
Subject(s)
COVID-19ABSTRACT
ObjectiveMany healthcare staff work in high-risk settings for contracting and transmitting Severe Acute Respiratory Syndrome Coronavirus 2. Their risk of hospitalisation for coronavirus disease 2019 (COVID-19), and that of their households, is poorly understood. Design and settings and participantsDuring the peak period for COVID-19 infection in Scotland (1st March 2020 to 6th June 2020) we conducted a national record linkage study to compare the risk of COVID-19 hospitalisation among healthcare workers (age: 18-65 years), their households and other members of the general population. Main outcomeHospitalisation with COVID-19 ResultsThe cohort comprised 158,445 healthcare workers, the majority being patient facing (90,733 / 158,445; 57.3%), and 229,905 household members. Of all COVID-19 hospitalisations in the working age population (18-65-year-old), 17.2% (360 / 2,097) were in healthcare workers or their households. Adjusting for age, sex, ethnicity, socio-economic deprivation and comorbidity, the risk of COVID-19 hospitalisation in non-patient facing healthcare workers and their households was similar to the risk in the general population (hazards ratio [HR] 0.81; 95%CI 0.52-1.26 and 0.86; 95%CI 0.49-1.51 respectively). In models adjusting for the same covariates however, patient facing healthcare workers, compared to non-patient facing healthcare workers, were at higher risk (HR 3.30; 95%CI 2.13-5.13); so too were household members of patient facing healthcare workers (HR 1.79; 95%CI 1.10-2.91). On sub-dividing patient-facing healthcare workers into those who worked in front-door, intensive care and non-intensive care aerosol generating settings and other, those in front door roles were at higher risk (HR 2.09; 95%CI 1.49-2.94). For most patient facing healthcare workers and their households, the estimated absolute risk of COVID-19 hospitalisation was less than 0.5% but was 1% and above in older men with comorbidity. ConclusionsHealthcare workers and their households contribute a sixth of hospitalised COVID-19 cases. Whilst the absolute risk of hospitalisation was low overall, patient facing healthcare workers and their households had 3- and 2-fold increased risks of COVID-19 hospitalisation.