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1.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-22276038

RESUMO

BackgroundHealthcare workers are at an increased risk of acquiring vaccine-preventable diseases and are known to be reliable source of information for the patients and their relatives. Knowledge and attitudes of Healthcare workers about vaccines are thus important determinants of their own vaccination uptake and their intention to recommend vaccinations to their patients. However, culturally adapted tools and studies to address vaccine uptake and hesitancy as well as related behaviours among Healthcare workers in the Global South are limited. MethodsWe propose a mixed methods project to understand the extent and determinants of vaccination hesitancy among Healthcare workers and construct a validated scale to measure this complex and context-specific phenomenon in Cape Town. We will summarise responses as counts and percentages for categorical variables and means with standard deviations (or median with inter quartile ranges) for continuous variables. We will run the Shapiro-Wilks test to assess the normality. Analysis of the variance, chi-square tests, and equivalents will be conducted as appropriate for group comparisons. Logistic regression models will also be performed to assess association between variables. We will focus on the seasonal influenza and COVID-19 vaccine. We will use an existing tool developed and validated in Germany and the United States of America to measure five psychological determinants of vaccination (referred to as the 5C scale), as the basis to develop and validate a scale to measure the scope and determinants of vaccine hesitancy and acceptance among Healthcare workers in Cape Town. Discussion and conclusionThrough this study, we hope to expand the scientific evidence based on vaccination acceptance and demand among Healthcare workers in South Africa and build resources to enable better understanding of, detection, and response to vaccination hesitancy in Cape Town.

2.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-21258218

RESUMO

Accurate assessment of SARS-CoV-2 immunity in the population is critical to evaluating vaccine efficacy and devising public health policies. Whilst the exact nature of effective immunity remains incompletely defined, SARS-CoV-2-specific T cell responses are a critical feature of the immune response that will likely form a key correlate of protection against COVID-19. Here, we developed and optimised a high-throughput whole blood-based assay to determine the T cell response associated with prior SARS-CoV-2 infection and/or vaccination amongst 156 healthy donors and 67 cancer patients. Following overnight in vitro stimulation with SARS-CoV-2-specific peptides, blood plasma samples were harvested and analysed for TH1-type effector cytokines (IFN-{gamma} and IL-2). Amongst healthy donors, highly significant differential IFN-{gamma}+/IL-2+ SARS-CoV-2-specific T cell responses were seen amongst vaccinated or previously infected COVID-19-positive individuals in comparison to unknown/naive individuals (P < 0.0001). IL-2 production from T cells in response to SARS-CoV-2 derived antigens was a highly predictive diagnostic assay (P < 0.0001; 96.0% sensitivity, 93.9% specificity); measurement of IFN-{gamma}+ SARS-CoV-2 specific T cell responses was equally effective at identifying asymptomatic (antibody and T cell positive) participants. A single dose of COVID-19 vaccine induced IFN-{gamma} and/or IL-2 SARS-CoV-2-specific T cell responses in 28/29 (96.6%) of healthy donors, reducing significantly to 27/56 (48.2%) when measured in cancer patients (P = 0.0003). Overall, this cost-effective standardisable test ensures accurate and comparable assessments of SARS-CoV-2-specific T cell responses amenable to widespread population immunity testing.

3.
Preprint em Inglês | medRxiv | ID: ppmedrxiv-21256479

RESUMO

ObjectivesTo describe the presentation and outcome of SARS-CoV2 infection in an African setting of high non-communicable co-morbidity and also HIV-1 and tuberculosis prevalence. DesignCase control analysis with cases stratified by HIV-1 and tuberculosis status. SettingA single-centre observational case-control study of adults admitted to a South African hospital with proven SARS-CoV-2 infection or alternative diagnosis. Participants104 adults with RT-PCR-proven SARS-CoV2 infection of which 55 (52.9%) were male and 31 (29.8%) HIV-1 co-infected. 40 adults (35.7% male, 30.9% HIV-1 co-infected) admitted during the same period with no RT-PCR or serological evidence of SARS-CoV2 infection and assigned alternative diagnoses. Additional in vitro data from prior studies of 72 healthy controls and 118 HIV-1 uninfected and infected persons participants enrolled to a prior study with either immune evidence of tuberculosis sensitization but no symptoms or microbiologically confirmed pulmonary tuberculosis. ResultsTwo or more co-morbidities were present in 57.7% of 104 RT-PCR proven COVID-19 presentations, the commonest being hypertension (48%), type 2 diabetes mellitus (39%), obesity (31%) but also HIV-1 (30%) and active tuberculosis (14%). Amongst patients dually infected by tuberculosis and SARS-CoV-2, clinical features could be dominated by either SARS-CoV-2 or tuberculosis: lymphopenia was exacerbated, and some markers of inflammation (D-dimer and ferritin) elevated in singly SARS-CoV-2 infected patients were even further elevated (p < 0.05). HIV-1 and SARS-CoV2 co-infection resulted in lower absolute number and proportion of CD4 lymphocytes, with those in the lowest peripheral CD4 percentage strata exhibiting absent or lower antibody responses against SARS-CoV2. Death occurred in 30/104 (29%) of all COVID-19 patients and in 6/15 (40%) of patients with coincident SARS-CoV-2 and tuberculosis. ConclusionsIn this South African setting, HIV-1 and tuberculosis are common co-morbidities in patients presenting with COVID-19. In environments in which tuberculosis is common, SARS-CoV-2 and tuberculosis may co-exist with clinical presentation being typical of either disease. Clinical suspicion of exacerbation of co-existent tuberculosis accompanying SARS-CoV-2 should be high. What is already known on this topic?It has been quite widely thought that Africa has been spared the worst effects of the COVID-19 pandemic. There are very few reported case series and no case-control studies comparing COVID-19 patients admitted to hospital to those admitted for other reasons. However several studies have indicated both HIV-1 and tuberculosis co-infection that are endemic in Africa constitute risk factors for poor outcome. In addition Africa is subject to demographic transition and the prevalence of non-communicable co-morbidities such as type 2 diabetes, hypertension and cardiovascular disease is rising rapidly. No study from Africa has described the clinical impact on the presentation of COVID-19 infection. What this study addsTwo or more co-morbidities were present in over half COVID-19 presentations, including HIV-1 (30%) and active tuberculosis (14%). Patients dually infected by tuberculosis and SARS-CoV-2, presented as either SARS-CoV-2 or tuberculosis. HIV-1 and SARS-CoV2 co-infection resulted in lower absolute number and proportion of CD4 lymphocytes, and those with low CD4 counts had absent or lower antibody responses against SARS-CoV2. Death occurred 29% of all COVID-19 patients and in 40% of patients with coincident SARS-CoV-2 and tuberculosis. Thus in environments in which tuberculosis is common, SARS-CoV-2 and tuberculosis may co-exist with clinical presentation being typical of either disease and clinical suspicion of exacerbation of co-existent tuberculosis accompanying SARS-CoV-2 should be high.

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