Reports from the CoMix social contact survey
This page list all our work on control measures for Covid-19.
Using a model of individual infectiousness and testing with lateral flow tests (LFT), we evaluate test-to-release policies against conventional fixed-duration isolation policies in terms of excess days of infectiousness, days saved, and tests used.
We model the potential consequences of the Omicron SARS-CoV-2 variant on transmission and health outcomes in England.
We evaluated the cost-effectiveness of vaccination against COVID-19 in Sindh, Pakistan
We estimated population changes in the UK using the location of Facebook users and show how time-varying populations influence a model of COVID-19.
We fitted a dynamic transmission model to satellite imagery of the main cemeteries in Mogadishu (Somalia) that showed an unexplained and sustained rise of burials in the period of late February to July 2020. Under the assumption that these excess deaths in Mogadishu were directly attributable to SARS-CoV-2 infection we arrived at median estimates of October-November 2019 for the date of introduction and low R0 estimates (1.3-1.5), stemming from the early and slow rise of excess deaths and their long plateau. Subject to study assumptions, a very early SARS-CoV-2 introduction event may have occurred in Somalia, while showing lower transmissibility in the first epidemic wave than observed in European settings.
We evaluate the utility of pre and post-flight PCR and lateral flow testing (LFT) to reduce transmission risk from infected arrivals and to reduce the duration of, or replace, quarantine. We also estimate the effectiveness of each strategy relative to domestic incidence, and limits of achievable risk reduction, for 99 countries where flight data and case numbers are estimated.
We present one full year of CoMix contact survey data from participants in England between March 2020 and March 2021 to track social contact behaviour during the Covid-19 pandemic.
Comment piece on the feasibility of reaching the herd immunity threshold against SARS-CoV-2, drawing comparisons with other vaccine-preventable pathogens.
Estimating the effect of using a follow-up PCR or lateral-flow test (LFT) upon a positive initial LFT in the mass asymptomatic testing of students in England.
Estimating a lower bound on test specificity using published data on LFD testing in educational settings
Combining multiple behavioural and epidemiological data sources with mathematical models, we analysed the transmissibility and impact of novel SARS-CoV-2 Variant of Concern 202012/01 in England.
We present the analyses of the impact of national and local restrictions on the number of setting-specific contacts that people have prior to and during the restrictions from an ongoing survey (CoMix) which tracks social contact behaviour during the Covid-19 pandemic.
Combining CoMix contact survey data with profiles in infectiousness and susceptibility to estimate the effect on the reproduction number.
A second wave of COVID-19 cases in Autumn 2020 led to localised, tiered “Alert Level” restrictions and subsequently a second national lockdown in England. We examine the impact of these tiered restrictions and options for lockdowns in terms of stringency, timing and length.
We evaluate the ability of different quarantine and testing strategies to reduce the transmission potential of traced secondary cases, accounting for PCR and lateral-flow antigen test sensitivities, test and trace delays, and varying levels of adherence.
Using globally available data sources with mathematical models, we analysed the transmissibility and severity of a novel SARS-CoV-2 variant, 501Y.V2, in South Africa.
We evaluated the impact of mass testing in Slovakia, in combination with other measures put in place around the time, by comparing infection prevalence in each round of testing.
Using data on twice weekly PCR testing of front-line healthcare workers, we estimated individual infection times and probability of testing PCR positive through time since infection.
Here we assess the merit of using lateral flow antigen (LFA) tests to allow for a shorter quarantine period by testing at its end, or to replace quarantine altogether by testing daily upon tracing and isolating only when test-positive.
Using reported data on COVID-19 cases and fatalities globally, we estimated the proportion of symptomatic cases that were reported in 210 countries and territories. We then use these estimates to attempt to reconstruct the pandemic.
We evaluated if Facebook for Good mobility data can provide information about movements within the UK during intervention periods and afterward.
To determine if interventions aimed at air travellers can delay establishment of a SARS-CoV-2 outbreak in a previously unaffected country with no shared border with China.
We simulated potential response strategies to assess their effectiveness in three African countries: Niger, Nigeria, and Mauritius.
We used an age-structured dynamic-transmission and economic model to explore different scenarios of immunisation programmes over ten years.
We evaluated routine surveillance/ testing strategies that can act as early warning systems in China.
We evaluated the effectiveness of the cordon sanitaire in Wuhan to delay or prevent outbreaks of COVID-19 in other major cities in mainland China.
We assessed the effectiveness of 13 groups of non-pharmaceutical interventions in reducing SARS-CoV-2 transmission using panel analysis and time-series clustering.
We update the synthetic contact matrices with the most recent data, comparing them to measured contact matrices, and develop customised contact matrices for rural and urban settings. We use these to explore the effects of physical distancing interventions for the COVID-19 pandemic in a transmission model.
We explored the potential of combining backward contact tracing with more conventional forward contact tracing for control of COVID-19.
We simulated the arrival of travellers infected with SARS-CoV-2 from the EU and USA to the UK. We assessed the performance of various testing and screening policies in terms of reducing the number of travellers released while still infectious and the number of days they remain infectious.
Using flight data, prevalence estimates and incidence estimates combined, we calculate the ratio of expected imported cases and local incidence globally.
Simulated isolation, tracing and quarantine control strategies for SARS-CoV-2 in a real-world social network generated from high resolution GPS data.
We use a stochastic age-structured transmission model to explore a range of COVID-19 intervention scenarios in the UK, including the introduction of school closures, social distancing, shielding of elderly groups, self-isolation of symptomatic cases, and extreme "lockdown"-type restrictions.
Projected epidemics in LMIC with and without interventions
We consider expanding the social bubble of either all households or only single occupance households or households with young children. We assess how the implementation of these strategies during lockdown impacts on the risk for Covid-19 resugence.
We analyse social contact data from Kenyan informal settlements to estimate if COVID-19 control measures have affected disease transmission, and economic and food security
Combining novel setting-specific social contact data from over 40,000 individuals in the UK with a mathematical model of COVID transmission, we compare the potential effects of isolation, contact tracing and physical distancing measures on epidemic control.
Interactive dashboard of Facebook colocation data
We examined human movement on multiple geographic scales to provide a complete picture of the overall dynamics while drawing links to their public health implications.
We evaluated the potential benefits of other respiratory infectious disease vaccines in the context of the COVID-19 pandemic.
We present the first results of an ongoing survey (CoMix) to track social contact behaviour during the Covid-19 pandemic, and compare social mixing to patterns found in a previous survey.
We estimate the proportion of observed cases that may have been caused by during the pre-symptomatic period of the corresponding primary cases.
To assess the viability of isolation and contact tracing to control transmission from imported cases of 2019-nCoV.
We evaluated effectiveness of thermal passenger screening for 2019-nCoV infection at airport exit and entry to inform public health decision-making.