Publications by authors named "Jean-Claude Thill"

Mathematical modeling of epidemic dynamics is crucial to understand its underlying mechanisms, quantify important parameters, and make predictions that facilitate more informed decision-making. There are three major types of models: mechanistic models including the SEIR-type paradigm, alternative data-driven (DD) approaches, and hybrid models that combine mechanistic models with DD approaches. In this paper, we summarize our work in the COVID-19 Scenario Modeling Hub (SMH) for more than 12 rounds since early 2021 for informed decision support.

View Article and Find Full Text PDF
Article Synopsis
  • COVID-19 is still a major public health issue in the U.S., with projected hospitalizations and deaths over the next two years varying based on assumptions about immune escape and vaccine recommendations.
  • Researchers used modeling to create six different scenarios combining levels of immune escape (20% and 50% per year) and CDC vaccination recommendations for different age groups.
  • In the worst-case scenario (high immune escape and no vaccination), COVID-19 could lead to over 2.1 million hospitalizations and around 209,000 deaths, while targeted vaccinations for seniors could significantly reduce these numbers.
View Article and Find Full Text PDF

Our ability to forecast epidemics far into the future is constrained by the many complexities of disease systems. Realistic longer-term projections may, however, be possible under well-defined scenarios that specify the future state of critical epidemic drivers. Since December 2020, the U.

View Article and Find Full Text PDF
Article Synopsis
  • COVID-19 is expected to continue causing significant hospitalizations and deaths in the U.S. from April 2023 to April 2025, with projections varying based on assumptions about immune escape and vaccination recommendations.
  • The study analyzes six scenarios based on different levels of immune escape (20% and 50% per year) and three vaccination strategies (no recommendation, vaccination for ages 65+, or vaccination for all eligible groups).
  • In the worst-case scenario, without vaccination and with high immune escape, projections estimate up to 2.1 million hospitalizations and 209,000 deaths, indicating a public health crisis that could surpass pre-pandemic influenza and pneumonia mortality rates.
View Article and Find Full Text PDF

Our ability to forecast epidemics more than a few weeks into the future is constrained by the complexity of disease systems, our limited ability to measure the current state of an epidemic, and uncertainties in how human action will affect transmission. Realistic longer-term projections (spanning more than a few weeks) may, however, be possible under defined scenarios that specify the future state of critical epidemic drivers, with the additional benefit that such scenarios can be used to anticipate the comparative effect of control measures. Since December 2020, the U.

View Article and Find Full Text PDF

Cities become mission-critical zones during pandemics and it is vital to develop a better understanding of the factors that are associated with infection levels. The COVID-19 pandemic has impacted many cities severely; however, there is significant variance in its impact across cities. Pandemic infection levels are associated with inherent features of cities (e.

View Article and Find Full Text PDF

The global COVID-19 pandemic has taken a heavy toll on health, social, and economic costs since the end of 2019. Predicting the spread of a pandemic is essential to developing effective intervention policies. Since the beginning of this pandemic, many models have been developed to predict its pathways.

View Article and Find Full Text PDF
Article Synopsis
  • The COVID-19 Scenario Modeling Hub brought together nine teams to analyze the effects of vaccinating children aged 5-11 against SARS-CoV-2 on COVID-19 outcomes in the U.S. from September 2021 to March 2022.
  • The study compared outcomes under scenarios with and without vaccination and the potential emergence of more transmissible variants, providing insights on case counts, hospitalizations, and deaths.
  • Findings indicated that vaccinating children could significantly reduce COVID-19 cases, hospitalizations, and deaths, offering both direct benefits for kids and indirect benefits for the broader population, even in scenarios with more transmissible variants.
View Article and Find Full Text PDF

Recognizing an urgent need to understand the dynamics of the pandemic's severity, this longitudinal study is conducted to explore the evolution of complex relationships between the COVID-19 pandemic, lockdown measures, and social distancing patterns in a diverse set of 86 countries. Collecting data from multiple sources, a structural equation modeling (SEM) technique is applied to understand the interdependencies between independent variables, mediators, and dependent variables. Results show that lockdown and confinement measures are very effective to reduce human mobility at retail and recreation facilities, transit stations, and workplaces and encourage people to stay home and thereby control COVID-19 transmission at critical times.

View Article and Find Full Text PDF

In Spring 2021, the highly transmissible SARS-CoV-2 Delta variant began to cause increases in cases, hospitalizations, and deaths in parts of the United States. At the time, with slowed vaccination uptake, this novel variant was expected to increase the risk of pandemic resurgence in the US in summer and fall 2021. As part of the COVID-19 Scenario Modeling Hub, an ensemble of nine mechanistic models produced 6-month scenario projections for July-December 2021 for the United States.

View Article and Find Full Text PDF

Background: SARS-CoV-2 vaccination of persons aged 12 years and older has reduced disease burden in the United States. The COVID-19 Scenario Modeling Hub convened multiple modeling teams in September 2021 to project the impact of expanding vaccine administration to children 5-11 years old on anticipated COVID-19 burden and resilience against variant strains.

Methods: Nine modeling teams contributed state- and national-level projections for weekly counts of cases, hospitalizations, and deaths in the United States for the period September 12, 2021 to March 12, 2022.

View Article and Find Full Text PDF

This paper focuses on advancing the traditional association rule mining (ARM) approach to capture the rich, multidimensional and multiscalar context that is anticipated to be associated with residential Motor Vehicle Theft (MVT) across urban environments. We tackle the challenge to materialize complex social and spatial components in the mining process and present a novel interactive visualization based on social network analysis of rules and associations to facilitate the analysis of mined rules. The spatial ARM (SARM) findings successfully identify many socio-spatial associations to MVT prevalence and establish their relative influence on crime outcome in a case study.

View Article and Find Full Text PDF

The ongoing COVID-19 global pandemic is touching every facet of human lives (e.g., public health, education, economy, transportation, and the environment).

View Article and Find Full Text PDF

Prediction of complex epidemiological systems such as COVID-19 is challenging on many grounds. Commonly used compartmental models struggle to handle an epidemiological process that evolves rapidly and is spatially heterogeneous. On the other hand, machine learning methods are limited at the beginning of the pandemics due to small data size for training.

View Article and Find Full Text PDF

There is a compelling and pressing need to better understand the temporal dynamics of public sentiment towards COVID-19 vaccines in the US on a national and state-wise level for facilitating appropriate public policy applications. Our analysis of social media data from early February and late March 2021 shows that, despite the overall strength of positive sentiment and despite the increasing numbers of Americans being fully vaccinated, negative sentiment towards COVID-19 vaccines still persists among segments of people who are hesitant towards the vaccine. In this study, we perform sentiment analytics on vaccine tweets, monitor changes in public sentiment over time, contrast vaccination sentiment scores with actual vaccination data from the US CDC and the Household Pulse Survey (HPS), explore the influence of maturity of Twitter user-accounts and generate geographic mapping of tweet sentiments.

View Article and Find Full Text PDF

What Is Already Known About This Topic?: The highly transmissible SARS-CoV-2 Delta variant has begun to cause increases in cases, hospitalizations, and deaths in parts of the United States. With slowed vaccination uptake, this novel variant is expected to increase the risk of pandemic resurgence in the US in July-December 2021.

What Is Added By This Report?: Data from nine mechanistic models project substantial resurgences of COVID-19 across the US resulting from the more transmissible Delta variant.

View Article and Find Full Text PDF

Mathematical models are powerful tools to study COVID-19. However, one fundamental challenge in current modeling approaches is the lack of accurate and comprehensive data. Complex epidemiological systems such as COVID-19 are especially challenging to the commonly used mechanistic model when our understanding of this pandemic rapidly refreshes.

View Article and Find Full Text PDF
Article Synopsis
  • Social media is increasingly viewed as a way to gather public opinion, but it has challenges like lack of structure and representativeness.
  • The study investigates if social media can provide quantifiable public opinion data and if this data can offer better insights compared to traditional opinion polls.
  • A new measurement approach was tested using Twitter data from the 2016 U.S. presidential election, showing that social media can yield more robust opinion metrics that complement traditional polling methods.
View Article and Find Full Text PDF

Background: Rabies is a significant public health problem in China. Previous spatial epidemiological studies have helped understand the epidemiology of animal and human rabies in China. However, quantification of effects derived from relevant factors was insufficient and complex spatial interactions were not well articulated, which may lead to non-negligible bias.

View Article and Find Full Text PDF