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The government have released the latest estimates for the COVID-19 R value and growth rates nationally and regionally across the UK.
Prof John Edmunds, Professor in the Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, said:
“Overall, R is probably a little below 1, but this is an overall estimate and masks quite a lot of variability due to local outbreaks. Also, there may be some evidence of more systematic variability in different parts of the UK, with Scotland and Wales probably having reproduction numbers towards the bottom end of the range observed for England, for instance.”
Dr Yuliya Kyrychko, Reader in Mathematics, University of Sussex, said:
“The changes in the R number in England and the UK overall are very small when compared to last week’s values to talk about any significant differences in the dynamics of epidemic. With smaller numbers of recorded cases and deaths, there is a greater degree of uncertainty in estimating this number, not to mention a delay in the effect of changing pattern of disease transmission on estimates of R. The fact that so far we have not observed a large growth in the number of cases, even with some of the restrictions being lifted, is a very good sign, though we should continue to exercise caution and maintain social distancing measures in order to minimise the potential of subsequent local outbreaks.”
Dr Konstantin Blyuss, Reader in Mathematics, University of Sussex, said:
“It is very reassuring to see that estimates of R number in London and Midlands have been revised slightly down compared to last week, though in terms of the effect of intervention in Midlands, perhaps, too little time has gone yet for it to have an effect. At the same time, the rates for South West have gone up slightly, and in other regions the values of R are very close to 1, with possible small but positive growth rates. This suggests that it is essential both to follow the prescribed guidelines, and to continue robustly monitoring local cases and deaths to make sure that if there is a local outbreak, it can be quickly contained, before it can potentially trigger a large growth in cases.”
Prof James Naismith FRS FRSE FMedSci, Director of the Rosalind Franklin Institute, and University of Oxford, said:
“That the number of cases is falling slightly is to be welcomed. This suggests, that so far, relaxation of the lockdown has not precipitated a second wave. It has to be emphasised that no one knows what the safe level of relaxation is for the UK and there is a delay between action and consequence. The virus is here and we could easily see a surge in cases if a mistake is made.
“Much more important than an individual decision to relax this or that measure, will be a willingness to admit error and reverse the decision in the light of new data. This how science works, with new and incomplete understanding, honest mistakes end up being made. With more data, errors are corrected without blame and shame, everyone moves forward. Things will end very badly for the UK, if the decision to relax or lock down a specific activity becomes a test of consistency or a contest to see who was ‘right all along’. A dose of humility is called for.
“The government is correct to draw attention to the problem with fixating on the R-value – it is not currently a particularly useful number. What is now crucial is that the testing regime is sampling sufficiently to detect any local hot spots, that the individual is supported to rapidly isolate, contacts are rapidly traced, rapidly tested and if needs be rapidly isolated. There is considerable room for improvement in this end-to-end process.
“These numbers also tell us that we are unlikely to eliminate the virus from the UK before the winter. In any event the virus has become global, without a vaccine we have to plan for its presence. It seems likely that the onset of colder weather will see the virus begin to spread more rapidly. We have a short breathing space to get ourselves organised to cope with the winter.”
Prof Oliver Johnson, Professor of Information Theory, University of Bristol, said:
“The fact that R is still estimated to be below 1 across the UK implies that the epidemic is continuing to shrink overall. This is consistent with the numbers observed through positive tests and deaths, which both continue to decline. There is uncertainty on these estimates because R cannot be directly measured and inferring its value becomes hard when the number of cases is low. For this reason it is not possible to rule out the possibility that the epidemic is growing in some regions, though values in the middle of the ranges given are most likely.
“There appear to be no particular trends in these numbers compared with last week, and the overall UK estimate has remained consistent at 0.7-0.9 over the last 7 weeks, suggesting that the weekly rate of decline is roughly constant. However it is too early to judge the effect of ‘Super Saturday’ openings based on these numbers, since any infections that took place last weekend are unlikely to have led to positive tests soon enough to influence them.”
All our previous output on this subject can be seen at this weblink:
www.sciencemediacentre.org/tag/covid-19
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