Reduction in mobility and COVID-19 transmission

Abstract

In response to the COVID-19 pandemic, countries have sought to control SARS-CoV-2 transmission by restricting population movement through social distancing interventions, thus reducing the number of contacts. Mobility data represent an important proxy measure of social distancing, and here, we characterise the relationship between transmission and mobility for 52 countries around the world. Transmission significantly decreased with the initial reduction in mobility in 73% of the countries analysed, but we found evidence of decoupling of transmission and mobility following the relaxation of strict control measures for 80% of countries. For the majority of countries, mobility explained a substantial proportion of the variation in transmissibility (median adjusted R-squared: 48%, interquartile range - IQR - across countries [27–77%]). Where a change in the relationship occurred, predictive ability decreased after the relaxation; from a median adjusted R-squared of 74% (IQR across countries [49–91%]) pre-relaxation, to a median adjusted R-squared of 30% (IQR across countries [12–48%]) post-relaxation. In countries with a clear relationship between mobility and transmission both before and after strict control measures were relaxed, mobility was associated with lower transmission rates after control measures were relaxed indicating that the beneficial effects of ongoing social distancing behaviours were substantial.

Spatio-temporal estimation of basic and effective reproduction number of COVID-19 and post-lockdown transmissibility in Bangladesh

“…Our results are similar to previously reported R 0 in China [ 17 , 27 ] and neighboring country India [ 28 ]. After a week of nation-wide lockdown, R t decreased substantially from early April 2020 in Bangladesh, which corroborates with those of [ 29 , 30 ]. Our finding suggests that Bangladesh has seen an upheaval of R t in early February 2021, which corroborates with Abbott et al [ 31 ].…”

Big data insight on global mobility during the Covid-19 pandemic lockdown

“…Our research has revealed that it is more relevant to look for a relationship between human mobility and Covid-19 transmission adopting a 14-day moving average. This observation is important, because much of the previous research into the impact of mobility reduction on Covid-19 transmission was based on smoothing data streams by using the 7-days rolling averaged mobility, leading to a significant difference in correlation analysis results [ 53 , 54 ]. This also applies to the sample size, which for the mentioned studies was 52 countries.…”

Estimating the effect of mobility on SARS-CoV-2 transmission during the first and second wave of the COVID-19 epidemic in Switzerland: a population-based study

“…[27] For this, mobility data were obtained from a mobile phone-based panel survey, whose participants were representative of the population by age, gender and region. Our research on the link between mobility and COVID-19 spreading extends beyond previous studies [10][11][12][13][14][15][16][17][18] by comparing the effect of mobility in two different waves.…”

“…Previous work found a positive association between mobility and transmission in the first wave but it was suspected for many countries worldwide that a decoupling in the relationship took place afterwards. [18][19][20] Our results suggest that human mobility is an important determinant for explaining reductions in SARS-CoV-2 transmission during both the first and the second wave in Switzerland. We found that the effect of a 1 % reduction in average daily travel distance on the effective reproduction number was of similar magnitude in both waves.…”