The potential rise in R after lockdown measures are relaxed is something that epidemiologists are well aware of. If the government delivers an effective testing and contact-tracing strategy that can bring the virus under control by the time lockdown measures are lifted for everyone, new cases of Covid-19 would theoretically be little cause for concern – as health authorities would have measures in place to identify and curb incipient outbreaks.


What’s of greater concern to epidemiologists are indications that the R number is rising uncontrollably, or in a way that increases the exposure of the most vulnerable or puts health systems under great strain. In other words, what’s as important as the R number is the total number of cases across a population that an increase in R would cause. While the increase in Germany’s R number is concerning, this would be far more alarming were it to occur in the UK, where there are currently many more cases of coronavirus.

Regional differences in the value of R are also important. Easing the lockdown in areas with greater health resources, fewer Covid-19 cases and where more people have already had the virus, may be practical compared with another part of the country where outcomes of an increasing R would be more severe. Differences in the R number among particular risk groups, such as care home residents, are also likely to be more meaningful than the value of R for the country as a whole. Again, we’ll need a widespread programme of testing and tracing to determine these risks, and enable health authorities to rapidly contain incipient outbreaks.
https://www.theguardian.com/commentisfree/2020/may/19/second-coronavirus-wave-r-number-uk-test-and-trace-mass-gatherings-travel?CMP=fb_gu&utm_medium=Social&utm_source=Facebook#Echobox=1589885394