Dataset Information

Assessing the impact of non-pharmaceutical interventions (NPIs) and BCG vaccine cross-protection in the transmission dynamics of SARS-CoV-2 in eastern Africa.

ABSTRACT:

Objective

The outbreak of the novel coronavirus disease 2019 (COVID-19) is still affecting African countries. The pandemic presents challenges on how to measure governmental, and community responses to the crisis. Beyond health risks, the socio-economic implications of the pandemic motivated us to examine the transmission dynamics of COVID-19 and the impact of non-pharmaceutical interventions (NPIs). The main objective of this study was to assess the impact of BCG vaccination and NPIs enforced on COVID-19 case-death-recovery counts weighted by age-structured population in Ethiopia, Kenya, and Rwanda. We applied a semi-mechanistic Bayesian hierarchical model (BHM) combined with Markov Chain Monte Carlo (MCMC) simulation to the age-structured pandemic data obtained from the target countries.

Results

The estimated mean effective reproductive number (R_t) for COVID-19 was 2.50 (C1: 1.99-5.95), 3.51 (CI: 2.28-7.28) and 3.53 (CI: 2.97-5.60) in Ethiopia, Kenya and Rwanda respectively. Our results indicate that NPIs such as lockdowns, and curfews had a large effect on reducing R_t. Current interventions have been effective in reducing R_t and thereby achieve control of the epidemic. Beyond age-structure and NPIs, we found no significant association between COVID-19 and BCG vaccine-induced protection. Continued interventions should be strengthened to control transmission of SARS-CoV-2.

SUBMITTER: Kilonzo CM

PROVIDER: S-EPMC9440862 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature

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Publications

Assessing the impact of non-pharmaceutical interventions (NPIs) and BCG vaccine cross-protection in the transmission dynamics of SARS-CoV-2 in eastern Africa.

Kilonzo Chelsea Mbeke CM Wamalwa Mark M Whegang Solange Youdom SY Tonnang Henri E Z HEZ

BMC research notes 20220904 1

<h4>Objective</h4>The outbreak of the novel coronavirus disease 2019 (COVID-19) is still affecting African countries. The pandemic presents challenges on how to measure governmental, and community responses to the crisis. Beyond health risks, the socio-economic implications of the pandemic motivated us to examine the transmission dynamics of COVID-19 and the impact of non-pharmaceutical interventions (NPIs). The main objective of this study was to assess the impact of BCG vaccination and NPIs en ...[more]

PMID: 36059028

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Project description:BackgroundNon-pharmaceutical interventions (NPIs) are critical for influenza control and prevention, however, the data about such interventions are insufficient among students in grades below middle school. Hence, this study aims to explore the effectiveness of NPIs (class-suspension and symptom-based isolation) on the control of influenza spread among children in primary school and kindergarten. Findings will support evidence-based strategies for influenza control among children enrolled in primary schools and kindergartens.MethodsWe purposively selected two regions (Zigong and Nanan) in Southwest China as study places, and class-suspension and symptom-based isolation was conducted in the two regions, respectively. RT (effective reproduction number) value, incidence cases, and attack rate were considered as outcome indicators. R4.1.2 software was used to conduct statistical analysis, and p < 0.05 (two-tailed) was considered as statistically significant.ResultsIn total, 593 students in the Nanan district received symptom-based isolation while 1340 students in Zigong city received class-suspension. The vaccination rate of Zigong (21.27%) was much greater than Nanan (8.26%) (p < 0.001). Parents in the Nanan were more highly educated, with undergraduate, master and above degrees, compared to parents in the Zigong (p < 0.05). Though there was no statistical significance difference in RT between Nanan (1.23) and Zigong (1.16) after quarantine and control measures were conducted, the RT value in the two regions was sharply decreased. The incident cases after class-suspension was much higher than symptom-based isolation in both kindergarten and primary school. The attack rate had a significant difference between class-suspension and symptom-based isolation in primary school (p < 0.05).ConclusionsBoth symptom-based isolation and class-suspension are effective measures in control of influenza spread, and symptom-based isolation are more effective than class-suspension in primary school. Health education and daily surveillance are needed in the control and prevention of influenza.

Project description:We report here on the characterisation in mice of a noninvasive bacille Calmette-Guérin (BCG) skin challenge model for assessing tuberculosis (TB) vaccine efficacy. Controlled human infection models (CHIMs) are valuable tools for assessing the relevant biological activity of vaccine candidates, with the potential to accelerate TB vaccine development into the clinic. TB infection poses significant constraints on the design of a CHIM using the causative agent Mycobacterium tuberculosis (Mtb). A safer alternative is a challenge model using the attenuated vaccine agent Mycobacterium bovis BCG as a surrogate for Mtb, and intradermal (skin) challenge as an alternative to pulmonary infection. We have developed a unique noninvasive imaging system based on fluorescent reporters (FluorBCG) to quantitatively measure bacterial load over time, thereby determining a relevant biological vaccine effect. We assessed the utility of this model to measure the effectiveness of 2 TB vaccines: the currently licenced BCG and a novel subunit vaccine candidate. To assess the efficacy of the skin challenge model, a nonlinear mixed-effects models was built describing the decline of fluorescence over time. The model-based analysis identified that BCG vaccination reduced the fluorescence readout of both fluorophores compared to unvaccinated mice (p < 0.001). However, vaccination with the novel subunit candidate did not alter the fluorescence decline compared to unvaccinated mice (p > 0.05). BCG-vaccinated mice that showed the reduced fluorescent readout also had a reduced bacterial burden in the lungs when challenged with Mtb. This supports the fluorescence activity in the skin as a reflection of vaccine induced functional pulmonary immune responses. This novel noninvasive approach allows for repeated measurements from the challenge site, providing a dynamic readout of vaccine induced responses over time. This BCG skin challenge model represents an important contribution to the ongoing development of controlled challenge models for TB.

Dataset Information

Assessing the impact of non-pharmaceutical interventions (NPIs) and BCG vaccine cross-protection in the transmission dynamics of SARS-CoV-2 in eastern Africa.

Objective

Results

Publications

Assessing the impact of non-pharmaceutical interventions (NPIs) and BCG vaccine cross-protection in the transmission dynamics of SARS-CoV-2 in eastern Africa.

Similar Datasets

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