A phase 2A trial of the safety and tolerability of increased dose rifampicin and adjunctive linezolid, with or without aspirin, for HIV-associated tuberculous meningitis (The LASER-TBM Trial) (preprint)

ABSTRACT Background Drug regimens which include intensified antibiotics alongside effective anti-inflammatory therapies may improve outcomes in Tuberculous Meningitis (TBM). Safety data on their use in combination and in the context of HIV is needed to inform clinical trial design. Methods We conducted a phase 2 open-label parallel-design RCT to assess safety of high-dose rifampicin, linezolid and aspirin in HIV-associated TBM. Participants were randomised (1.4:1:1) to three treatment arms (arm 1, standard of care (SOC); arm 2 SOC + additional rifampicin (up to 35mg/kg/day)) + linezolid 1200mg/day reducing after 28/7 to 600mg/day; arm 3, as per arm 2 + aspirin 1000mg/day) for 56 days, when the primary outcome of adverse events of special interest (AESI) or death was assessed. Results 52 participants were randomised. 59% had mild disease (MRC Grade 1) vs 39% (Grade 2) vs 2% (Grade 3). 33% of participants had microbiologically-confirmed TBM; vs 41% ‘possible’ or 25% ‘probable’. AESI or death occurred in 10/16 (arm 3) vs 4/14 (arm 2) vs 6/20 (arm 1) ( p=0 . 083 ). The cumulative proportion of AESI or death (Kaplan-Meier method) demonstrated worse outcomes in arm 3 vs arm 1 ( p=0 . 04 ), however only one event in arm 3 was attributable to aspirin and was mild. There was no difference in efficacy (Modified Rankin Scale) at day 56 between the three arms. Conclusions High-dose rifampicin and adjunctive linezolid can safely be added to SOC in HIV-associated TBM. Larger studies are required to evaluate whether potential toxicity associated with these interventions, particularly aspirin, is outweighed by mortality or morbidity benefit. SUMMARY In this phase 2a randomised control trial we demonstrate that high-doserifampicin and adjunctive linezolid is safe in adult HIV-associated tuberculous meningitis. Larger studies are required to evaluate potential toxicity with aspirin, in relation to benefit on morbidity and mortality.

Influenza Vaccination Hesitancy and Acceptance among Healthcare Workers in Cape Town, South Africa (preprint)

Vaccination attitudes among healthcare workers (HCWs) is a vital factor for measuring their level of vaccination uptake and intention to recommend vaccinations to their patients. To our knowledge, no study has been conducted in South Africa to assess hesitancy to influenza vaccines among HCWs. We used questionnaire adapted from Betsch and colleagues to conduct an online and face-to-face cross-sectional study among HCWs at the start of COVID-19 vaccine roll-out prior to the flu season. Main outcome was influenza vaccine hesitancy. We used multivariate logistic regression to assess predictors of influenza vaccine hesitancy. Of 401 participants, 64.5% were women, 49.2% nurses, and 12.5% physicians. A total of 54.9% were willing to accept vaccination, 20.4% were undecided, and 24.7% intended to refuse. Older participants above 17-25 years and physicians were likely to receive the vaccine. Key predictors of vaccine acceptance were confidence in the effectiveness, consideration of benefits and risks, and willingness to be vaccinated to protect others. Influenza vaccine hesitancy was highest in those who did not trust that influenza vaccines are safe. For future flu seasons, tailored education programs targeting younger HCWs and more information about the composition of flu vaccines would be vital to improve vaccine uptake.

Cross-Cultural Adaptation and Validation of the 5C Scale to Identify Factors Associated With COVID-19 and Influenza Vaccine Hesitancy Among Healthcare Workers in Cape Town, South Africa - A Protocol (preprint)

Background: Healthcare 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. Methods: We 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 conclusion: Through 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.

Whole blood-based measurement of SARS-CoV-2-specific T cell responses reveals asymptomatic infection and vaccine efficacy in healthy subjects and patients with solid organ cancers (preprint)

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.

Communicable and non-communicable co-morbidities and the presentation of COVID-19 in an African setting of high HIV-1 and tuberculosis prevalence (preprint)

Objectives To 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. Design Case control analysis with cases stratified by HIV-1 and tuberculosis status. Setting A single-centre observational case-control study of adults admitted to a South African hospital with proven SARS-CoV-2 infection or alternative diagnosis. Participants 104 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. Results Two 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 less than 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. Conclusions In 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.