Data for case numbers of COVID-19 published on the government online dashboard have shown falling numbers for 5 consecutive days.
Prof Karl Friston, Professor of Imaging Neuroscience, UCL, and panellist on the ‘Independent SAGE’ with special responsibility for modelling, said:
“From a dynamic causal modelling perspective, the recent fall in case rates is unremarkable. This kind of modelling predicts the current resurgence of infections will peak around now, with no further surges until winter. For example, real-time estimates of the effective reproduction ratio fell to one about a week or so ago. Interestingly, there was an estimated surge in contact rates that peaked around June 28 – that may or may not be related to the Euros 2020 and other changes in our behaviour. Furthermore, the model predicts that contact rates will remain relatively low (e.g., about 80% of pre-pandemic rates) for the next month. This prediction flies in the face of unlocking on July 19 but is consistent with the school summer holidays and opportunities for outdoor socialising. It also speaks to the importance of personal mitigating behaviours – and suggests that we, as a population, will remain vigilant until prevalence falls.
“Under these fluctuations in contact rates, the current reduction in infection rates is sufficiently modelled by the efficacy of vaccination in precluding transmission, in conjunction with high levels of vaccination and heterogeneity in susceptibility. The modelling predicts that the R number will increase from about four at the present time to about six as winter approaches – due largely to seasonality effects. If this is correct, the key questions now are how do we prepare effectively for a winter resurgence; especially, with a nuanced shift from a focus on mortality to morbidity, such as long COVID and post COVID syndrome – and the secondary effects on healthcare beyond COVID-19.
“In short, the current decline in cases is not surprising from certain modelling perspectives. It may be that people have been over interpreting the worst-case scenario modelling from the SPI-M that suggested a hundred thousand cases per day over the summer. However, these reports are carefully qualified and say explicitly that they are not forecasts and predictions. In contrast, any modelling that tries to make predictions will be, by definition, more optimistic than any worst-case scenario modelling – and should be regarded as such.”
Dr Stephen Griffin, Associate Professor in the School of Medicine, University of Leeds, said:
“The recent fall in cases in England is great news, but also puzzling given that progressive relaxation of restrictions has occurred, with the final release of all measures last week. Notably, test positivity rates continue to remain relatively high. It will be important to see whether the results of the ONS survey this week are in agreement with a fall in prevalence. Hospitalisations and deaths are sadly continuing to increase, but this would be expected given the known lag between these occurrences and the onset of infection.
“Whilst this appears to be good news, I would be surprised if we are likely to see a continuation of this decline and there are many factors that one can speculate – and at present we can only speculate – might have contributed to this. First, the ongoing coverage of the so-called ‘pingdemic’, unhelpful as it has been, actually reflect the fact that, in response to a large surge of infections, a great many people have been asked to self-isolate recently and this could have a direct impact upon transmission. Similarly, the large number of school bubbles that have been closing may also have reduced transmission, plus we are now in the holiday period, further reducing contacts. One troubling concern is that people might actively avoid being put forward for testing as a result of messaging that minimises the dangers of infection, or that vaccinated individuals with mild symptoms might not realise they are infected; whilst the latter are likely to represent a relatively small proportion of cases, this could still result in transmission given current absence of restrictions.
“This all speaks to the importance of self-isolation and limiting the opportunities for spread when controlling a highly transmissible virus, such as the delta variant. We have also had weather that would promote more outdoor and less indoor mixing, which again might curb spread. It may be that continuation of these factors might indeed reduce the predicted peak of infection over the summer. However, given that the full effect of unlocking last week might not have been seen based upon relatively steady increases in mobility data, it is important not to assume anything at this stage. Behaviour is a major factor in driving spread and case reductions appear consistent across the country.
“What we can be more certain about is what is highly unlikely to have caused the reduction in cases. It is clear that this cannot realistically be due to achieving a relevant level of population immunity given that only just over half the UK population has received both vaccines. Whilst 90% of adults in the UK have been reported to possess antibodies resulting from either vaccination or infection (ONS), we know the latter results in a dramatically inferior level of protection. We also know that protection versus delta increases considerably with the second vaccine dose, so it really is the vaccination programme that is likely to be most important here. It is also the case that the drop in cases appears primarily within younger groups that are less likely – or indeed mainly unable if under 18 – to have received both vaccines.
“It also seems unlikely that the opening of indoor venues such as nightclubs will not have had an impact on spread, given that prevalence amongst younger people in some areas was documented last week at around 1 in 50. Reduced compliance with mask wearing and distancing, particularly indoors, and without numbers being limited can only serve to increase spread as well.
“So, on balance, this is very much a waiting game and the outcome will depend upon how the factors listed above, or indeed others, interact over the summer and translate to new infections. However, one thing is abundantly clear, if this reduction in cases continues or not, the government simply must use this opportunity to increase vaccination rates before the autumn, and if further disruption in schools and harm to young people is to be avoided this should include adolescents and vulnerable children younger than 12. Only by increasing our coverage dramatically can we ensure that the clinically vulnerable and those unable to either receive, or respond to a vaccine are also protected as we move towards the winter.”
Prof James Naismith, Director of the Rosalind Franklin Institute, and University of Oxford, said:
“Any drop in case numbers is great news and to be warmly welcomed. I hope these testing numbers which show such a rapid drop in infections are an accurate reflection of reality.
“The roll out of vaccines in the UK has clearly made a huge difference to hospitalisations and deaths.
“The warmer summer days have also helped.
“Recent weeks have seen a real drop in the number of first vaccinations. I would urge the government, medics and my fellow scientists to continue to explain to the vaccine hesitant the benefits of these safe and effective medicines.
“At the same time, the hot air around masking is over shadowing uncontroversial plans to improve ventilation. I realise the debate about masks generates an enthusiasm that makes ventilation seem rather mundane by comparison. However getting more vaccinations and improving ventilation will do much more to save lives than any amount of shouting for or against masks.
“The ONS survey which will be published on Friday will cover the covid19 infection up to Saturday just past, will give us a very good sense of where we are. One can speculate endlessly on reasons why the ONS survey and daily test result may differ. Speculation serves no purpose when we will know whether there is actually any divergence on Friday, let’s wait for the data. In the meantime, daily up or downs in the numbers has little value in understanding disease progression.
“For me the next milestone will be the ONS data release on Friday 21st August, we will know for sure the effect of the end of the lockdown. It is important to understand that the daily test numbers will only begin to see the effect of the end of lockdown towards the end of this week. Many scientists, myself included, expect the end of lockdown to see a rise in cases. However, we have been wrong before and we will be wrong in the future. Only charlatans claims omniscience. This is a new disease and we are learning more every day.”
Prof Adam Finn, Professor of Paediatrics, University of Bristol, said:
“We need to be pleased about the recent fall in daily numbers of positive tests. Not confident about the implications, nor certain of what may happen next, but pleased simply because the numbers have spent 5 days not going up even further and faster. That means less viral transmission and eventually fewer hospitalisations and deaths than we feared and expected a week ago.
“There are certainly multiple factors at play here. These include infection-induced immunity, vaccine-induced immunity and, critically, behaviour. We still have enough non-immune people around to reverse this trend if we completely stop trying to avoid spreading the infection and, self-evidently, many people are still making an effort to avoid becoming infected and infecting others, helped by the recent sunny weather that keeps us all outside. The people who got their second doses of vaccine a week or more ago are now getting their boosted immune protection. Those who received their first doses 3 weeks ago are now at lower risk themselves and to others. With every passing day another cohort of people, recently immunised, is added to our protection alongside those who have recently had the infection, survived and recovered.
“Together we desperately need to keep this happening if we can. It’s a joint effort. There’s a lot we can all do. We need to test ourselves before we go to work or mix with others, always wear a mask in crowded places and when inside with others – places to avoid for now whenever possible – and, above all, get vaccinated. All these measures help keep the wave down, but vaccination is the only weapon we have that can really snuff the virus out.”
All our previous output on this subject can be seen at this weblink:
Dr Stephen Griffin: No conflicts
Prof Adam Finn: “AF is an investigator in trials and studies of several COVID19 vaccines including Oxford-AZ, Pfizer, Janssen, Valneva and Sanofi and advises the UK government and the WHO on COVID19 and other vaccines. He receives no personal income for this work and is remunerated solely through his employment by the University of Bristol.”
None others received.