Restrictions put in place by various countries — school and office closure, ban on public events, travel restrictions etc — did help restrict the spread of Covid-19, but combined measures were more effective than any single restriction, a new study published in The Lancet Infectious Diseases has found.
University of Edinburgh researchers took data from 131 countries and ranked various non-pharmaceutical interventions (NPIs)for their effectiveness.
How they worked it out
The calculations are based on the R number — which indicates the number of healthy persons to whom an infected individual can transmit the virus within a population group.
The researchers investigated the effect of separate and combined interventions on transmission, by estimating the R number when these interventions are introduced and lifted. “To the best of our knowledge, this study is the first to assess the temporal association between changing the status of a range of NPIs and the transmission of SARS-CoV-2, as measured by R, for all countries for which data were available,” they wrote.
Daily estimates of R were linked with the measures in place from January to July. A timeline was created for each country, which was divided into individual phases(within any phase, all measures remained unchanged).
Using complex modelling, the researchers linked the restrictions in each phase with changes in R. 📣 Follow Express Explained on Telegram
Single vs package
24% Bans on public events were found to cause the single highest reduction. R dropped 24% within 28 days. Other measures were not found to have a significant effect on their own.
29% The team modelled four “packages” that combined a number of measures. The least restrictive of these — ban on public events, ban on gatherings of more than 10 — reduced R by 29% on day 28.
52% This was the reduction caused by a package of school and workplace closure, ban on public events and gatherings of more than ten people, limits on movement and a stay-at-home requirement.
Don’t miss from Explained | The plasma therapy debate
📣 The Indian Express is now on Telegram. Click here to join our channel (@indianexpress) and stay updated with the latest headlines