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1.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-22280191

RESUMEN

ObjectivesTo assess whether workplace exposures as estimated via a COVID-19 Job Exposure Matrix (JEM) are associated with SARS-CoV-2. MethodsData on 244,470 participants were available from the ONS Coronavirus Infection Survey (CIS) and 16,801 participants from the Virus Watch Cohort, restricted to workers aged 20 to 64. Analysis used logistic regression models with SARS-CoV-2 as the dependent variable for eight individual JEM domains (number of workers, nature of contacts, contact via surfaces, indoor or outdoor location, ability to social distance, use of face covering, job insecurity, migrant workers) with adjustment for age, sex, ethnicity, Index of Multiple Deprivation (IMD), region, household size, urban vs rural area, and health conditions. Analyses were repeated for three time periods (i) February 2020 (Virus Watch)/April 2020 (CIS) to May 2021), (ii)June 2021 to November 2021, (iii) December 2021 to January 2022. ResultsOverall, higher risk classifications for the first six domains tended to be associated with an increased risk of infection, with little evidence of a relationship for domains relating to proportion of workers with job insecurity or migrant workers. By time there was a clear exposure-response relationship for these domains in the first period only. Results were largely consistent across the two cohorts. ConclusionsAn exposure-response relationship exists in the early phase of the COVID-19 pandemic for number of contacts, nature of contacts, contacts via surfaces, indoor or outdoor location, ability to social distance and use of face coverings. These associations appear to have diminished over time.

2.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-22273177

RESUMEN

BackgroundConsiderable concern remains about how occupational SARS-CoV-2 risk has evolved during the COVID-19 pandemic. We aimed to ascertain which occupations had the greatest risk of SARS-CoV-2 infection and explore how relative differences varied over the pandemic. MethodsAnalysis of cohort data from the UK Office of National Statistics Coronavirus (COVID-19) Infection Survey from April 2020 to November 2021. This survey is designed to be representative of the UK population and uses regular PCR testing. Cox and multilevel logistic regression to compare SARS-CoV-2 infection between occupational/sector groups, overall and by four time periods with interactions, adjusted for age, sex, ethnicity, deprivation, region, household size, urban/rural neighbourhood and current health conditions. ResultsBased on 3,910,311 observations from 312,304 working age adults, elevated risks of infection can be seen overall for social care (HR 1.14; 95% CI 1.04 to 1.24), education (HR 1.31; 95% CI 1.23 to 1.39), bus and coach drivers (1.43; 95% CI 1.03 to 1.97) and police and protective services (HR 1.45; 95% CI 1.29 to 1.62) when compared to non-essential workers. By time period, relative differences were more pronounced early in the pandemic. For healthcare elevated odds in the early waves switched to a reduction in the later stages. Education saw raises after the initial lockdown and this has persisted. Adjustment for covariates made very little difference to effect estimates. ConclusionsElevated risks among healthcare workers have diminished over time but education workers have had persistently higher risks. Long-term mitigation measures in certain workplaces may be warranted. What is already known on this topicSome occupational groups have observed increased rates of disease and mortality relating to COVID-19. What this study addsRelative differences between occupational groups have varied during different stages of the COVID-19 pandemic with risks for healthcare workers diminishing over time and workers in the education sector seeing persistent elevated risks. How this study might affect research, practice or policyIncreased long term mitigation such as ventilation should be considered in sectors with a persistent elevated risk. It is important for workplace policy to be responsive to evolving pandemic risks.

3.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-22273752

RESUMEN

Hybrid immunity (infection plus vaccination) provided high protection against infection and severe disease in the periods of delta and gamma variants of concern. However, the protection of hybrid immunity in the Omicron era remains unknown. We performed a test-negative study using Brazilian national databases between January 01 and March 22, 2022, a period of predominant circulation of the Omicron variant in Brazil. Hybrid immunity offered low protection against infection, with rapid waning, compared to unvaccinated with or without previous infection. For severe illness (hospitalisation or death), the protection, although already high for unvaccinated pre-infected increased regardless of the type of vaccine (Ad26.COV2.S, BNT162b2, ChAdOx-1 or CoronaVac). In conclusion, during the Omicron-dominant period in Brazil, hybrid immunity offered high protection against severe illness and low protection against infection.

4.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-22271075

RESUMEN

ObjectivesTo assess total antibody levels against Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS CoV-2) spike protein up to 12 months after Coronavirus Disease (COVID-19) infection in non-vaccinated individuals and the possible predictors of antibody persistence. MethodsThis is a prospective multi-centre longitudinal cohort study. ParticipantsThe study included SARS-CoV-2 real-time polymerase chain reaction (RT-PCR) positive and negative participants in South-Eastern Norway from February to December 2020. Possible predictors of SARS-CoV-2 total antibody persistence was assessed. The SARS-CoV-2 total antibody levels against spike protein were measured three to five months after PCR in 391 PCR-positive and 703 PCR-negative participants; 212 PCR-positive participants were included in follow-up measurements at 10 to 12 months. The participants completed a questionnaire including information about symptoms, comorbidities, allergies, body mass index (BMI), and hospitalisation. Primary outcomeThe SARS-CoV-2 total antibody levels against spike protein three to five and 10 to 12 months after PCR positive tests. ResultsSARS-CoV-2 total antibodies against spike protein were present in 366 (94%) non-vaccinated PCR-positive participants after three to five months, compared with nine (1%) PCR-negative participants. After 10 to 12 months, antibodies were present in 204 (96%) non-vaccinated PCR-positive participants. Of the PCR-positive participants, 369 (94%) were not hospitalised. The mean age of the PCR-positive participants was 48 years (SD 15, range 20-85) and 50% of them were male. BMI [≥] 25 kg/m2 was positively associated with decreased antibody levels (OR 2.34, 95% CI 1.06 to 5.42). Participants with higher age and self-reported initial fever with chills or sweating were less likely to have decreased antibody levels (age: OR 0.97, 95% CI 0.94 to 0.99; fever: OR 0.33, 95% CI 0.13 to 0.75). ConclusionOur results indicate that the level of SARS-CoV-2 total antibodies against spike protein persists for the vast majority of non-vaccinated PCR-positive persons at least 10 to 12 months after mild COVID-19.

5.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-22269194

RESUMEN

Between August-September 2021, an outbreak of SARS-CoV-2, with an attack rate of 55% (22/40 workers), occurred in a public-facing office in England. To identify workplace and worker-related risk factors, a comprehensive investigation involving surface sampling, environmental assessment, molecular and serological testing, and worker questionnaires was performed in September - October 2021. The results affirm the utility of surface sampling to identify SARS-CoV-2 control deficiencies and the importance of evolving, site-specific risk assessments with layered COVID-19 mitigation strategies.

6.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-21268058

RESUMEN

BackgroundCOVID-19 vaccines have proven highly effective among SARS-CoV-2 naive individuals, but their effectiveness in preventing symptomatic infection and severe outcomes among individuals with prior infection is less clear. MethodsUtilizing national COVID-19 notification, hospitalization, and vaccination datasets from Brazil, we performed a case-control study using a test-negative design to assess the effectiveness of four vaccines (CoronaVac, ChAdOx1, Ad26.COV2.S and BNT162b2) among individuals with laboratory-confirmed prior SARS-CoV-2 infection. We matched RT-PCR positive, symptomatic COVID-19 cases with RT-PCR-negative controls presenting with symptomatic illnesses, restricting both groups to tests performed at least 90 days after an initial infection. We used multivariable conditional logistic regression to compare the odds of test positivity, and the odds of hospitalization or death due to COVID-19, according to vaccination status and time since first or second dose of vaccines. FindingsAmong individuals with prior SARS-CoV-2 infection, vaccine effectiveness against symptomatic infection [≥] 14 days from vaccine series completion was 39.4% (95% CI 36.1-42.6) for CoronaVac, 56.0% (95% CI 51.4-60.2) for ChAdOx1, 44.0% (95% CI 31.5-54.2) for Ad26.COV2.S, and 64.8% (95% CI 54.9-72.4) for BNT162b2. For the two-dose vaccine series (CoronaVac, ChAdOx1, and BNT162b2), effectiveness against symptomatic infection was significantly greater after the second dose compared with the first dose. Effectiveness against hospitalization or death [≥] 14 days from vaccine series completion was 81.3% (95% CI 75.3-85.8) for CoronaVac, 89.9% (95% CI 83.5-93.8) for ChAdOx1, 57.7% (95% CI -2.6-82.5) for Ad26.COV2.S, and 89.7% (95% CI 54.3-97.7) for BNT162b2. InterpretationAll four vaccines conferred additional protection against symptomatic infections and severe outcomes among individuals with previous SARS-CoV-2 infection. Provision of a full vaccine series to individuals following recovery from COVID-19 may reduce morbidity and mortality. FundingBrazilian National Research Council, Fundacao Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro, Oswaldo Cruz Foundation, JBS S.A., Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation, Generalitat de Catalunya. RESEARCH IN CONTEXTO_ST_ABSEvidence before this studyC_ST_ABSWe searched PubMed, medRxiv, and SSRN for articles published from January 1, 2020 until December 15, 2021, with no language restrictions, using the search terms "vaccine effectiveness" AND "previous*" AND ("SARS-CoV-2" OR "COVID-19"). We found several studies evaluating ChAdOx1 and BNT162b2, and one additionally reporting on mRNA-1273 and Ad26.COV2.S, which found that previously infected individuals who were vaccinated had lower risk of symptomatic SARS-CoV-2 infection. One study found that risk of hospitalization was lower for previously infected individuals after a full series of BNT162b2 or mRNA-1273. Limited evidence is available comparing effectiveness of one versus two doses among individuals with prior infection. No studies reported effectiveness of inactivated vaccines among previously infected individuals. Added value of this studyWe used national databases of COVID-19 case surveillance, laboratory testing, and vaccination from Brazil to investigate effectiveness of CoronaVac, ChAdOx1, Ad26.COV2.S and BNT162b2 among individuals with a prior, laboratory-confirmed SARS-CoV-2 infection. We matched >22,000 RT-PCR-confirmed re-infections with >145,000 RT-PCR-negative controls using a test-negative design. All four vaccines were effective against symptomatic SARS-CoV-2 infections, with effectiveness from 14 days after series completion ranging from 39-65%. For vaccines with two-dose regimens, the second dose provided significantly increased effectiveness compared with one dose. Effectiveness against COVID-19-associated hospitalization or death from 14 days after series completion was >80% for CoronaVac, ChAdOx1and BNT162b2. Implications of all the available evidenceWe find evidence that four vaccines, using three different platforms, all provide protection to previously infected individuals against symptomatic SARS-CoV-2 infection and severe outcomes, with a second dose conferring significant additional benefits. These results support the provision of a full vaccine series among individuals with prior SARS-CoV-2 infection.

7.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-21266124

RESUMEN

BackgroundMonitoring differences in COVID-19 vaccination uptake in different groups is crucial to help inform the policy response to the pandemic. A key gap is the absence of data on uptake by occupation. MethodsUsing nationwide population-level data, we calculated the proportion of people who had received two doses of a COVID-19 vaccine (assessed on 31 August 2021) by detailed occupational categories in adults aged 40-64 and estimated adjusted odds ratios to examine whether these differences were driven by occupation or other factors, such as education. We also examined whether vaccination rates differed by ability to work from home. ResultsOur study population included 14,298,147 adults 40-64. Vaccination rates differed markedly by occupation, being higher in administrative and secretarial occupations (90.8%); professional occupations (90.7%); and managers, directors and senior officials (90.6%); and lowest (83.1%) in people working in elementary occupations. We found substantial differences in vaccination rates looking at finer occupational groups even after adjusting for confounding factors, such as education. Vaccination rates were higher in occupations which can be done from home and lower in those which cannot. Many occupations with low vaccination rates also involved contact with the public or with vulnerable people ConclusionsIncreasing vaccination coverage in occupations with low vaccination rates is crucial to help protecting the public and control infection, especially in occupations that cannot be done from home and involve contacts with the public. Policies such as work from home if you can may only have limited future impact on hospitalisations and deaths What is already known on this subject?Whilst several studies highlight differences in vaccination coverage by ethnicity, religion, socio-demographic factors and certain underlying health conditions, there is very little evidence on how vaccination coverage varies by occupation, in the UK and elsewhere. The few study looking at occupational differences in vaccine hesitancy focus on healthcare workers or only examined broad occupational groups. There is currently no large-scale study on occupational differences in COVID-19 vaccination coverage in the UK. What this study adds?Using population-level linked data combining the 2011 Census, primary care records, mortality and vaccination data, we found that the vaccination rates of adults aged 40 to 64 years in England differed markedly by occupation. Vaccination rates were high in administrative and secretarial occupations, professional occupations and managers, directors and senior officials and low in people working in elementary occupations. Adjusting for other factors likely to be linked to occupation and vaccination, such as education, did not substantially alter the results. Vaccination rates were also associated with the ability to work from home, with the vaccination rate being higher in occupations which can be done performed from home. Policies aiming to increase vaccination rates in occupations that cannot be done from home and involve contacts with the public should be priorities

8.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-21257123

RESUMEN

ObjectiveTo estimate occupational differences in COVID-19 mortality, and test whether these are confounded by factors, such as regional differences, ethnicity and education or due to non-workplace factors, such as deprivation or pre-pandemic health. DesignRetrospective cohort study SettingPeople living in private households England Participants14,295,900 people aged 40-64 years (mean age 52 years, 51% female) who were alive on 24 January 2020, living in private households in England in 2019, were employed in 2011, and completed the 2011 census. Main outcome measuresCOVID-19 related death, assessed between 24 January 2020 and 28 December 2020. We estimated age-standardised mortality rates per 100,000 person-years at risk (ASMR) stratified by sex and occupations. To estimate the effect of occupation due to work-related exposures, we used Cox proportional hazard models to adjust for confounding (region, ethnicity, education), as well as non-workplace factors that are related to occupation. ResultsThere is wide variation between occupations in COVID-19 mortality. Several occupations, particularly those involving contact with patients or the public, show three-fold or four-fold risks. These elevated risks were greatly attenuated after adjustment for confounding and mediating non-workplace factors. For example, the hazard ratio (HR) for men working as taxi and cab drivers or chauffeurs changed from 4.60 [95%CI 3.62-5.84] to 1.47 [1.14-1.89] after adjustment. More generally, the overall HR for men working in essential occupations compared with men in non-essential occupations changed from 1.45 [1.34 - 1.56] to 1.22 [1.13 - 1.32] after adjustment. For most occupations, confounding and other mediating factors explained about 70% to 80% of the age-adjusted hazard ratios. ConclusionsWorking conditions are likely to play a role in COVID-19 mortality, particularly in occupations involving contact with COVID-19 patients or the public. However, there is also a substantial contribution from non-workplace factors, including regional factors, socio-demographic factors, and pre-pandemic health.

9.
Preprint en Inglés | medRxiv | ID: ppmedrxiv-20116608

RESUMEN

Covid-19 death has a different relationship with age than is the case for other severe respiratory pathogens. The Covid-19 death rate increases exponentially with age, and the main risk factors are age itself, as well as having underlying conditions such as hypertension, diabetes, cardiovascular disease, severe chronic respiratory disease and cancer. Furthermore, the almost complete lack of deaths in children suggests that infection alone is not sufficient to cause death; rather, one must have gone through a number of changes, either as a result of undefined aspects of aging, or as a result of chronic disease. These characteristics of Covid-19 death are consistent with the multistep model of disease, a model which has primarily been used for cancer, and more recently for amyotrophic lateral sclerosis (ALS). We applied the multi-step model to data on Covid-19 case fatality rates (CFRs) from China, South Korea, Italy, Spain and Japan. In all countries we found that a plot of ln (CFR) against ln (age) was approximately linear with a slope of about 5. As a comparison, we also conducted similar analyses for selected other respiratory diseases. SARS showed a similar log-log age-pattern to that of Covid-19, albeit with a lower slope, whereas seasonal and pandemic influenza showed quite different age-patterns. Thus, death from Covid-19 and SARS appears to follow a distinct age-pattern, consistent with a multistep model of disease that in the case of Covid-19 is probably defined by comorbidities and age producing immune-related susceptibility. Identification of these steps would be potentially important for prevention and therapy for SARS-COV-2 infection.

10.
Asia Pacific Allergy ; (4): 161-178, 2013.
Artículo en Inglés | WPRIM (Pacífico Occidental) | ID: wpr-749953

RESUMEN

BACKGROUND: Eczema is a common chronic disease which has significant morbidity and costs for children and their families. Phase One (1993) of the International Study of Asthma and Allergies in Childhood (ISAAC) found a high prevalence of symptoms of eczema in New Zealand. OBJECTIVE: In Phase Three (2001-3) we aimed to answer these three questions: Is the prevalence of eczema changing over time?; Are there ethnic differences in prevalence?; and What are the risk factors for eczema? METHODS: Five New Zealand centres participated in ISAAC Phases One and Three using the same methodology. Questionnaires about ethnicity, symptoms of eczema and environmental factors were completed by parents of 6-7 year olds (children) and self-completed by 13-14 year olds (adolescents). Prevalence and change per year were calculated by centre, ethnicity and gender. Prevalence differences between centres and associations with environmental factors were examined using logistic regression. RESULTS: There was little change in prevalence over time for the children, and a decrease in prevalence for the adolescents. Prevalence was higher among Māori and even higher among Pacific participants than among European children. Positive associations with current eczema symptoms were found for both age groups for truck traffic in the street of residence, and current paracetamol consumption, and for children only, antibiotics or paracetamol in the 1st year of life. Inverse associations were found with residence in New Zealand less than 5 years, consumption of milk, seafood, and eggs, and presence of a dog in the home. CONCLUSION: Eczema remains a significant problem, particularly for young Māori and Pacific New Zealanders in whom less recognition of eczema and poorer access to effective, sustained eczema management may be contributing factors. Reverse causation may explain all the environmental findings apart from truck traffic which is increasing in New Zealand.


Asunto(s)
Adolescente , Animales , Niño , Perros , Humanos , Acetaminofén , Antibacterianos , Asma , Enfermedad Crónica , Eccema , Huevos , Hipersensibilidad , Modelos Logísticos , Leche , Vehículos a Motor , Nueva Zelanda , Óvulo , Padres , Prevalencia , Factores de Riesgo , Alimentos Marinos
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