Challenges in addressing inequity in access to COVID-19 diagnostics, therapeutics and vaccines in Africa

Although the global response to COVID-19 has demonstrated that some progress has been made in ensuring timely access to new medical interventions in Africa, much more needs to be done to strengthen the global systems that enable equitable access to health technologies during public health emergencies.

Adherence Therapy for adults with type 2 diabetes: a feasibility study of a randomised controlled trial (preprint)

BackgroundAdherence Therapy is a candidate intervention to promote consistent medication taking in people with type 2 diabetes. The aim of this study was to establish the feasibility of conducting a randomised controlled trial of Adherence Therapy in people with type 2 diabetes who were non-adherent with medication.MethodsAn open-label, single-centre, randomised controlled feasibility trial. Participants were randomly allocated to receive either eight sessions of telephone delivered Adherence Therapy or treatment as usual. Recruitment occurred during the COVID-19 pandemic. Outcome measures – adherence, beliefs about medication and HbA1c – were administered at baseline and after eight weeks or at the completion of treatment. Feasibility outcomes included the number of people initiated to participate in the trial that consented, completed study measures, finished treatment with adherence therapy, and dropped out of the trial.ResultsSeventy-eight people were screened of which 39 met eligibility criteria and were invited to take part in the trial. Thirteen people consented to participate, were enrolled in the trial and randomised. Five (71%) of the seven participants in the Adherence Therapy arm completed treatment. Baseline measures were completed by all participants. Week 8 (post-treatment) measures were completed by eight (62%) participants. Drop out may have been linked with a poor understanding of what was involved in taking part in the trial.ConclusionsIt may be feasible to conduct a full RCT of Adherence Therapy, but careful consideration should be given to developing effective recruitment strategies, consent procedures, rigorous field testing and clear support materials.Trial registrationThe trial was prospectively registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), ACTRN12619000827134, on the 7th June 2019.

Robust test and trace strategies can prevent COVID-19 resurgences: a case study from New South Wales, Australia (preprint)

Background: The early stages of the COVID-19 pandemic illustrated that SARS-CoV-2, the virus that causes the disease, has the potential to spread exponentially. Therefore, as long as a substantial proportion of the population remains susceptible to infection, the potential for new epidemic waves persists even in settings with low numbers of active COVID-19 infections, unless sufficient countermeasures are in place. In this study, we examine the Australian state of New South Wales, a setting with prolonged low transmission, high mobility, non-universal mask usage, and a well-functioning test-and-trace system. We investigate how vulnerable the state would be to resurgences in COVID-19 transmission under variations in the levels of testing, tracing, and mask usage. Methods: We use a stochastic agent-based model, calibrated to the New South Wales epidemic and policy environment, to simulate possible epidemic outcomes over October 1 to December 31, 2020, under a range of assumptions about contact tracing efficacy, testing rates, and mask uptake. Results: We find that the relative impact of masks is greatest when testing and tracing rates are lower (and vice versa). With very high testing rates (90% of people with symptoms, plus 90% of people with a known history of contact with a confirmed case), we estimate that the epidemic would remain under control until at least the end of 2020, with as little as 70-110 new infections estimated over October 1 to December 31 under high mask uptake scenarios, or 340-1400 without masks, depending on the efficacy of community contact tracing. However, across comparable levels of mask uptake and contact tracing, the number of infections over this period would be up to 6 times higher if the testing rate was 80% instead of 90%, 17 times higher if the testing rate was 65%, or more than 100 times higher with a 50% testing rate. Conclusions: Our work suggests that testing, tracing and masks can all be effective means of controlling transmission in dynamic community settings. A multifaceted strategy that combines all three, alongside continued hygiene and distancing protocols, is likely to be the most robust means of controlling community-based transmission of SARS-CoV-2.

The role of masks in reducing the risk of new waves of COVID-19 in low transmission settings: a modeling study (preprint)

Objectives: To evaluate the risk of a new wave of coronavirus disease 2019 (COVID-19) in a setting with ongoing low transmission, high mobility, and an effective test-and-trace system, under different assumptions about mask uptake. Design: We used a stochastic agent-based microsimulation model to create multiple simulations of possible epidemic trajectories that could eventuate over a five-week period following prolonged low levels of community transmission. Setting: We calibrated the model to the epidemiological and policy environment in New South Wales, Australia, at the end of August 2020. Participants: None Intervention: From September 1, 2020, we ran the stochastic model with the same initial conditions (i.e., those prevailing at August 31, 2020), and analyzed the outputs of the model to determine the probability of exceeding a given number of new diagnoses and active cases within five weeks, under three assumptions about future mask usage: a baseline scenario of 30% uptake, a scenario assuming no mask usage, and a scenario assuming mandatory mask usage with near-universal uptake (95%). Main outcome measure: Probability of exceeding a given number of new diagnoses and active cases within five weeks. Results: The policy environment at the end of August is sufficient to slow the rate of epidemic growth, but may not stop the epidemic from growing: we estimate a 20% chance that NSW will be diagnosing at least 50 new cases per day within five weeks from the date of this analysis. Mandatory mask usage would reduce this to 6-9%. Conclusions: Mandating the use of masks in community settings would significantly reduce the risk of epidemic resurgence.

Optimal Subsidies for Home Delivery in Times of COVID-19 (preprint)

In times of COVID-19, there are negative externalities associated with in-store shopping since if one is infectious one might transmit the disease to others. What is the optimal Pigovian subsidy for home delivery of food to internalize this externality? To address this question, we develop a model with three policy instruments: testing frequency, lockdown intensity, and a subsidy for home delivery of food. First, we consider the case where the testing frequency is adjusted so as to keep the pandemic's reproduction rate fixed. In this case, the value of the subsidy for home delivery is to allow for a reduction in the testing rate without affecting the reproduction number. This substitution is plausible when the testing rate is chosen optimally. Using illustrative calibrations for the US, we find in this case that the optimal ad valorem subsidy for home delivery of food is between 1.7% and 3.4%. However, it might be more likely that the testing rate continues to be chosen at a suboptimal level. In this case, reducing the reproduction rate of COVID-19 via subsidies for home delivery could cause a reduction in the expected lockdown intensity. Even if only 10% of the reduction in the reproduction rate is offset via reduced lockdown intensity, an ad valorem subsidy of between 5.4% and 10.8% will be warranted on these grounds alone.