Mathematical Epidemiology 
Spread of Covid-19 


COVID-19 Epidemiological Round Table Discussions

The COVID-19 Epidemiological Modelling Project has started a series of round table discussion sessions on the pandemic. For participants who like to take part in the discussion, use the Zoom URL

Meeting-ID: 843 1697 2876

Round table discussion take place on Thursdays  17:00 CET (Paris-Berlin-Rome) - 4:00 p.m. GMT (London)

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Please contact Lisa Maria Kreusser if you have suggestions for round table discussion topics.

COVID-19 Epidemiological Modelling Seminar Series

The COVID-19 Epidemiological Modelling Project has started a series of talks on the pandemic. Previous talks can be viewed again on YouTube:

SARA Systems Streaming

This channel is also used for live streaming of the talks. For participants who like to take part in the discussion, use the Zoom URL

Meeting-ID: 843 1697 2876

Talks are given on Thursdays  18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Subscription link:

Modelling the deceleration of COVID-19 spreading

Lecture on 11/03/2021, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Speaker: Marco Baiesi

Abstract: An analysis of COVID-19 data detects a deceleration of the epidemic in its early stages, often before a lockdown. Moreover, from the deceleration of the number of new cases we can also quantify the portion of population not involved in the lockdown, in different countries. Our analysis starts by characterising the time evolution of COVID-19 in term of its "velocity" (log of the new cases per day) and its rate of variation, or "acceleration" and continues by modifying a susceptible-hidden-infected-recovered (SHIR) model introduced in 2020 by Barnes. A partial hiding mechanism, for instance due to the impossibility for a fraction of the population to enter the hidden state, yields a simple model that can reproduce different deceleration trends. We also discuss other related simple models of COVID-19.

Link to this talk's announcement.

The How, Why and What of Measuring Political Systems' Deliberativeness

Lecture on 25/02/2021, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Speaker: Dannica Fleuß

Abstract: Measuring democratic deliberation is necessary for a valid measurement of democratic quality or legitimacy. Yet, it poses serious theoretical-conceptual and methodological challenges. The most serious problem in the context of research on democratic performance is the need for a theoretical and methodological approach for “upscaling” the measurement of deliberation from the micro and meso level to the macro level. I propose a systemic framework for this purpose. Building on this framework, I offer a modular approach and outline strategies for conceptualization, measurement, and aggregation which can be adjusted to make the measurement of democratic deliberation suitable for various research goals and purposes. I refer to exemplary findings from ongoing and recent research projects to illustrate the individual steps or ‘modules’.

Link to this talk's announcement.

A Decision Support System based on Artificial Intelligence for risk evaluation. A model to treat emergencies related to COVID pandemic.

Lecture on 11/02/2021, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Speaker: Silvia Liberata Ullo

Abstract: Due to the spread of COVID-19 pandemic, many governments and local institutions (regions and municipalities) worldwide have applied severe lockdown measures, but have always made a posteriori decision: increasing levels of lockdown have been activated, based on the number of infected, hospitalized and dead, all the up to a generalized lockdown, like the one imposed in Italy from the beginning of March until almost the end of June, and in many other countries worldwide as well. However, the lockdown measures have proven to result in different outcomes in different countries, since several factors impact the efficiency of the lockdown measures. Moreover, these methods of intervention were not appropriate due to their negative implications for economic and social aspects.

A new tool to support institutions in the implementation of targeted countermeasures, based on quantitative and multi-scale elements, for the fight and prevention of emergencies, such as the current COVID-19 pandemic is described. The tool is a cloud-based centralized system; a multi-user platform that relies on artificial intelligence (AI) algorithms for the processing of heterogeneous data, which can produce as an output the level of risk. The tool is realized in two steps: the first training phase will serve later both as a decision support system (DSS) with predictive capacity, when fed by the actual measured data, and as a simulation bench performing the tuning of certain input values, to identify which of them led to a decrease in the degree of risk. In this way, it is possible to deal with different scenarios and compare different restrictive strategies and the actual expected benefits, to adopt measures sized to the actual needs, adapted to the specific areas of analysis and useful for safeguarding human health; and trying to evaluate the economic and social impacts of the choices.

A project still in progress is here described [1], but some preliminary analyses are shown, and two different case studies presented, whose results have highlighted a correlation between NO2, mobility and COVID-19 data. However, given the complexity of the virus diffusion mechanism, linked to air pollutants but also to many other factors, these preliminary studies confirmed the need, on the one hand, to carry out more in-depth analyses, and on the other, to use AI algorithms to capture the hidden relationships among the huge amounts of involved data.

[1] Sebastianelli, A.; Mauro, F.; Di Cosmo, G.; Passarini, F.; Carminati, M.; Ullo, S.L. AIRSENSE-TO-ACT: A Concept Paper for COVID-19 Countermeasures Based on Artificial Intelligence Algorithms and Multi-Source Data Processing. ISPRS Int. J. Geo-Inf. 2021, 10, 34.

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SEIRD-CA-SDL model for COVID-19 containment scenarios in Catalonia

Lecture on 14/01/2021, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Speaker: Pau Fonseca

Abstract: Based on a validated SEIRD model for SARS-CoV-2 spread, we expand the model using Cellular Automata to simplify the definition for different health regions affected by the pandemic. We define a conceptualization using Specification and Description Language, a formal language that allows us to extend the model to a Cellular Automaton (CA). In this talk we point some forecast scenarios for Catalonia done in June. We present some formalization details, we discuss some validation process implications, following a digital twin approach. We discuss some results obtained from the model and we point some implications of decision making based on models.

Link to this talk's announcement.

Recent and Upcoming Round Table Discussions

17/12/2020, Thursday 17:00 CET (Paris-Berlin-Rome) - 4:00 p.m. GMT (London)

Discussion topic: The Present and the Future of the Covid-19 Pandemic

We would like to invite you to an end-of-the-year roundtable discussion on the global Covid-19 pandemic. We will invite all the speakers of our Covid-19 initiative speaking this year for a final debate on the state of this crisis.

After the speakers giving their individual updates, we then proceed with a roundtable discussion, which I will chair, on the following topics:

​Behavioural changes in the population since spring 2020​

Policy measures by governments in 2020​

Track & Trace efficiencies (including mobile apps), in all of 2020​

Functioning of the health systems in all of 2020​

Update on vaccination strategies for 2021​


29/10/2020, Thursday 17:00 CET (Paris-Berlin-Rome) - 4:00 p.m. GMT (London)

Discussion topic: How successful are different lockdown strategies? For this, we will focus on the Great Barrington Declaration and the John Snow Memorandum.


22/10/2020, Thursday 17:00 CET (Paris-Berlin-Rome) - 4:00 p.m. GMT (London)

Discussion topic: How effective are lockdowns?


15/10/2020, Thursday 17:00 CET (Paris-Berlin-Rome) - 4:00 p.m. GMT (London)

Discussion topic: Why are infections rising again in Europe?


Cognitive Frames, Habits, Culture, Institutions – Features and Mechanisms to Reduce Complexity and Explain / Enable Action

Lecture on 26/11/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Speaker: Matthias Gsänger

Abstract: Like any other virus, COVID-19 depends on humans meeting each other and behaving in certain patterns. All over the world governments attempt to curtail the spread of COVID-19 by influencing and controlling their citizens behaviour. At this both “government agencies” and “normal people” appear as actors, that, facing a new, uncertain situation, experience themselves as compelled to restructure their perception and action. Both process information concerning COVID-19 according to their own (cognitive) structures and both consider signals from each other. In this contribution I want to put some socioscientific approaches up for discussion concerning their power to describe and explain relevant social phenomena and their suitability for translating those descriptions into mathematics.

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Overview of the COVID-19 pandemic in Ontario and modelling efforts 

Lecture on 12/11/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Speaker: Chris Bauch

Abstract: In terms of culture, politics, and economy, Canada has often been conceptualized as a hybrid between the United States and Europe. In this talk I will start with an overview of how the COVID-19 pandemic is unfolding in Ontario, including a comparison between the US and European experiences. Then I will summarize major findings from several of the transmission models that my research group and collaborators have developed to inform the pandemic response. These models range in structure from an agent-based model of transmission in schools and households, to province-scale stochastic and deterministic compartmental models. The types of questions we use these models to address include: what is the impact of class size on the number of cases and lost student-days of in-person instruction? What are the conditions under which a county-by-county approach to lockdown can work as well as a province-wide lockdown? And, which age groups should get the vaccine first?

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COVID 2019 - Public Health Perspective and Disaster Response in India

Lecture on 30/07/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Speaker: Sunita Reddy

Abstract: India is a second populous country with limited resources, complex social systems, structural inequalities, diverse multicultural and multi-ethnic society. Given its vast coastline, diverse topography and geographical condition, it faces disasters more frequently. Despite its robust three-tier health care service system and Disaster Management Institutional structures, there are many gaps and challenges to mitigate disasters, especially at the scale of today's pandemic. Further, the crevices in the social structures get more pronounced during disasters. Through this talk, the author will walk through the COVID 2019 disaster response in India and the challenges in mitigating from a public health perspective. Lockdown has given scope to rethink on more sustainable ways of development as it is closely linked with disasters and capture the lessons learnt from past mistakes.

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The Coronavirus Stimulus Package: How large is the transfer multiplier?


Lecture on 23/07/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Title: The Coronavirus Stimulus Package: How large is the transfer multiplier?

Speaker: Christian Bayer

Abstract: In response to the COVID-19 pandemic, large parts of the economy have been locked down and, as a result, households' income risk has risen sharply. At the same time, policy makers have put forward the largest stimulus package in history. In the U.S., it amounts to $2 trillion, a quarter of which is earmarked for transfer payments to households. To the extent that such transfers are conditional on recipients being unemployed, they mitigate income risk and the adverse impact of the lockdown ex ante. Unconditional transfers, in contrast, stabilize income ex post. We simulate the effects of a lockdown in a medium-scale HANK model and quantify the impact of transfers. For the short run, we find large differences in the transfer multiplier: it is 0.25 for unconditional transfers and 1.5 for conditional transfers. Overall, we find that the transfers reduce the output loss due to the pandemic by up to 5 percentage points.

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Link to this talk's announcement.

I know I don't know: Tests, and Covid-19 Patients' Journeys through Hospital


Lecture on 16/07/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Title:  I know I don't know: Tests, and Covid-19 Patients' Journeys through Hospital

Speaker: Jane Hutton

Abstract: How do we know it's covid-19? I was asked to consider the available data on Covid-19 patients' path into hospital, and then to intensive care, or death, or transfer or discharge. Of course, once in intensive care, patients can move to the states death, discharge home, discharge to nursing home, discharge to hospital ward. I was invited by those who think I know about analysis of times to events with messy data. The data is messy. This means many challenges with testing, tracing, and weighing risks and benefits. The changes in British government responses appear to be driven by different interpretations of questions and answers.


Link to this talk's announcement.

Models to understand Emerging Pathogens at the Dawn of the Covidocene

Lecture on 09/07/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Title: Models to understand Emerging Pathogens at the Dawn of the Covidocene

Speaker: Andy Dobson

Abstract: The arrival and emergence of Covid-19 has had a major impact on human health and the global economy. The emergence of Covid-19 and other emergent pathogens was not unexpected, here I will review a number of recent models that look at the factors that lead to pathogen emergence. Once they have emerged, it is increasingly hard to stop their spread. So what do models tell us about preventing emergence and what are the relative costs of prevention relative to control once the pathogen has emerged.

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Basic Reproduction Numbers, Effective Reproduction Numbers and Herd Immunity

Lecture on 02/07/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Title: Basic Reproduction Numbers, Effective Reproduction Numbers and Herd Immunity

Speaker: Tom Britton

Abstract: We start by defining some basic concepts for the simplest epidemic model and then extend the results to a wider class of epidemic models allowing for some population heterogeneities. We end by showing an important new result: the disease-induced herd immunity level $h_D\( is smaller than the classical herd immunity level \)h_C=1-1/R_0$. 

Link to this talk's announcement.

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Some of Tom's simulations can be viewed here.


Brazil in the Time of Covid-19

Lecture on 25/06/2020, Thursday 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Title: Brazil in the Time of Covid-19

Speaker: Ronald Poon-Affat

Abstract: Presentation will include brazilian point of view on 1) most credible data sources/projection models both from international and brazilian sites 2) why is modelling Brazilian covid-19 so challenging 3) is there any good news to share 4) government's plan/expectation in reopening


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Evolution of the COVID-19 Epidemic in México

Lecture on 18/06/2020, 18:00 CET (Paris-Berlin-Rome) - 5:00 p.m. GMT (London)

Title:  Evolution of the COVID-19 Epidemic in México

Speaker: Moises Santillan

Moises Santillan has a blog with the newest Mexican data presented in his talk.

Blog entry at: