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expert reaction to televised address on COVID-19 situation by CSA Patrick Vallance and CMO Chris Whitty

The government Chief Scientific Advisor (CSA, and the Chief Medical Officer for England (CMO) gave a public address covering the state of the COVID-19 pandemic in the UK. 


Dr Flavio Toxvaerd, University Lecturer at the Faculty of Economics, University of Cambridge, who specialises in the economics of infectious diseases and economic epidemiology, said:

“I am an economist who works with infection control – I am involved in modelling disease and in making projections, but from a slightly different methodological perspective than epidemiologists.

“It is hard to make accurate predictions about infection numbers and so epidemiologists often work with ‘reasonable worst-case scenarios’ to guide policy responses.  These projections often rely on behavioural assumptions that are unlikely to be borne out in practice and so the projections often look too gloomy in retrospect.

“Most epidemiologists are not trained to analyse human behaviour, a key to understanding the spread of diseases like COVID-19.  They therefore model disease dynamics by essentially guessing how people will respond to different policy measures.  The worst-case scenarios that are depicted in the graphs assume that people do nothing at all to protect themselves, something most epidemiologists agree is highly unlikely to be the case.  In practice, the expectation is that people will self-protect and thereby curb the epidemic somewhat.

“These issues are what drive public health officials to emphasise that the graphs are “not predictions” but rather “what can happen”; and Patrick Vallance and Chris Whitty made clear these were not predictions.  In practice, the scenarios are often used for policy purposes and in much of the subsequent coverage and messaging, the worst-case scenarios are used as if they were in fact predictions.

“It is a difficult balance to strike.  Public health officials must communicate something but in doing so, must also be honest about what can be known.  If these subtleties are not properly communicated and the scenarios don’t materialise, people can come to mistrust scientists and think that they are engaged in scaremongering.  In fairness, these are very difficult issues to communicate effectively and I believe that Vallance and Whitty did a good job today.”


Prof Martin Hibberd, Professor of Emerging Infectious Disease, London School of Hygiene and Tropical Medicine, said:

“The review of where we are now with COVID-19 given by Whitty and Vallance today was a helpful up-date; but was given significance by the comments that “we have reached a turning point”.  It seems that the science has handed this information over to the politicians, who now need to decide what the next steps should be and no doubt we will hear some decisions in the next few days.  Perhaps what was not talked about so much is why we have reached this step-change in infections.  While the increase in social contacts brought about by the relaxing of lock down was a well-known risk, this was meant to be mitigated by increased testing and contact tracing – we have had the last three months to prepare for this.  With numbers of cases low (after the difficult lock down), local transmission hotspots and positive cases should have been identified by the testing and tracing system.  With cases and their contacts isolating, numbers of new cases should have been controlled, but clearly this has failed.  A good response to the turning point we now find ourselves in would be to ensure that our testing and tracing program is improved sufficiently in the next week or so, to catch up with world leading examples found in Germany, South Korea, Singapore and others, so that we do not need to bring in new social distancing measures.”


Dr Julian Tang, Honorary Associate Professor in Respiratory Sciences, University of Leicester, said:

“Most people have still not been infected with COVID-19 and are still susceptible in the UK.  The coming colder months will just bring people indoors more often and increase the transmission risk.

“The figures of how many people have had the infection in the past and now are almost certainly underestimates – due to relatively poor track-and-trace figures, delayed/lack of testing, and the ongoing unknown numbers of incubating presymptomatic and asymptomatic COVID-19 cases.

“The hands-face-space message is the wrong way round – it should be space-face-hands.  Even a UK SAGE review has shown that hand/fomite/contact transmission only accounts for just 20% of all respiratory virus transmission – with presumably 80% due to droplet/aerosols:

“And the US CDC has just upgraded their COVID-19 guidance to state that aerosols are the main way that this virus transmits:

“Social distancing and masking are more effective than hand-washing to reduce the transmission of this virus – this does not mean that we stop washing our hands, but just be more vigilant about ventilation and masking in crowded indoor spaces.

“Natural infection and probably any vaccine are not going to stop all COVID-19 reinfection – but in the absence of a licensed vaccine at the moment, staying far enough apart and masking to stop the virus from transmitting is the best we can do, short of complete lockdown.

“The numbers of people wearing face coverings in the UK is increasing but could be improved further – note that in Asian countries where they are more compliant with masking (e.g. Taiwan, Hong Kong, Thailand, Vietnam) their infection rates are far lower:

“And presumably, even for those who don’t like having to use them, wearing face coverings more carefully and vigilantly is preferable to another full national lockdown.

“One silver lining is that, hopefully, based on what we’ve seen in Australia, the usual seasonal respiratory virus (including from influenza) burden should be less this year – especially if more people are immunised against seasonal influenza:”


Prof Mark Woolhouse, Professor of Infectious Disease Epidemiology, University of Edinburgh, said:

“The suggestion of a potential 50,000 new cases per day mentioned in today’s press briefing will inevitably cause consternation as it would put the UK right at the top of the list of world’s countries affected by COVID-19.

“Only 3 countries in the world – India, USA and Brazil – have ever reported more than 50,000 new cases per day (though in the early stages of the pandemic there will have been substantial under-reporting).

“Only India is currently reporting more than 50,000 cases per day.

“That number of cases in the UK corresponds to 75 per 100,000 population per day.

“At present, the worst affected country in the world (other than Aruba) is Israel with 51 cases per 100,000 population per day.

“Many observers may consider this an implausible scenario.  Presumably the UK government intends it to illustrate the consequences of sustained exponential growth.”


Dr Daniel Lawson, Senior Lecturer in Statistical Science, School of Mathematics, University of Bristol, said:

“The range of infection to expect in the future is hard to predict because it depends so strongly on what response we take.

“Is 50,000 cases per day plausible?  We are currently only recording around 3,000 cases per day, and at the maximum recorded was around 5,000.  But during March and for much of the first wave, testing was negligible and estimates for the peak true number of daily cases are in the tens of thousands.  Under half a million people will be infected to get us to that point, so it is possible.

“There is no modelling detail provided for the 50k infection rate scenario in October.  At present it appears as a simple extrapolation from the current reproductive rate of COVID-19.  This is not likely to be accurate over a timescale of weeks, as the infection would need to access different populations, not all of whom take the same risks.  For example, outbreaks in younger people who are still attending pubs and meeting socially will not replicate at the same rate in older people with less adventurous lifestyles.

“So the number is plausible if the UK as a whole does not respond to the outbreak, but an increase in compliance and risk avoidance will make it unlikely to come about as predicted.  Additional local or national interventions will also reduce the infections.

“In other words, the scenario is unlikely to come about – but we do need to pay attention to it anyway, because the public do need to take action to lower the infection rate and only some of this is achieved by policy; the rest is done by us.  If we ignore this scenario, it could yet come about, or worse restrictions put in place instead.”


Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:

“It is important to note that the Chief Medical Office did say the potential for 50k cases a day is a ‘worst case scenario’.  Modelling has to calculate best, worst, and likely scenarios to allow different plans to be put in place.  We are very unlikely to see cases at that level because interventions will be rolled out that restrict the spread of the virus, such as regional lockdowns.  However, it is a timely reminder that the pandemic is accelerating both globally and also here in the UK.”


Dr Freya Jephcott, Research Fellow in Emerging Infectious Diseases, The University of Cambridge, said:

“The lack of mention of adverse outcomes other than death is a concerning gap in the narrative presented today. There is increasing evidence that a significant minority of people under 45 years of age, including children, will develop a protracted form of the illness which last months, if not years.

“Data from the Kings College London ZOE app suggests that at least 60,000 people from across a range of age groups have developed this ‘Long-haul’ form of Covid in the UK.  Further, 39 doctors personally afflicted by ‘Long Covid’ published a letter in the BMJ last week emphasising their concerns that these adverse outcomes were not being adequately captured by current COVID surveillance approaches and not being incorporated into public health messaging and decision making:”


Dr Rupert Beale, Group Leader, Cell Biology of Infection Laboratory, Francis Crick Institute, said:

“Professors Whitty and Vallance provided an accurate summary of where the UK is now in this pandemic.  Professor Vallance is absolutely right to highlight the low levels of immunity in the UK.  Even areas which were very badly hit in the first wave, such as London, do not have anywhere near the levels of immunity required for a ‘herd immunity’ effect.  He also pointed out the very promising developments in vaccination, and suggested that we would be able to manage the pandemic very differently by the time these become available.

“Professor Whitty reminded us that the virus is likely to spread more easily during the winter months.  He also clearly outlined the very serious consequences of letting the virus get out of control.  This would lead to many additional indirect deaths due to NHS resources being diverted from other healthcare priorities.  We should all do our bit by minimising our risk of contracting and spreading the virus: keeping our distance, washing our hands, and wearing masks indoors.  Ministers will need to make important judgements on how best to suppress transmission over what will be a very difficult winter.”


Nigel Marriott FRSS, Independent Statistician, said:

“Here are my comments on the regional charts on page 5:

“These charts show the pattern by Upper Tier Local Authority (UTLA) up to 9th September.  In the week following that up to 15th September there has been a marked divergence between the North and the South & Midlands.  This was not mentioned and I think it should have been.  My interpretation of the 150 UTLA data as of 15th September is that we already have a second wave in the North with doubling rates of every week to every fortnight, but in the South we have a reversal with number of positive tests falling in the latest week.  The Midlands is in between.  Overall, in the week to 15th September, 94 out of 150 UTLAs saw a fall in positive tests and 53 recorded a rise with nearly all of those being in the North.  This regional disparity makes the national picture hard to interpret and it suggests that the goal should be to halt the Northern wave as fast as possible before it has a chance to spread to the South.”


Dr Flavio Toxvaerd, University Lecturer at the Faculty of Economics, University of Cambridge, who specialises in the economics of infectious diseases and economic epidemiology, said:

“The presentations by Whitty and Valance were very effective science communication and struck the right tone.  They patiently set out the challenges we are collectively facing over the coming months, without compromising on accuracy and detail.

“It is particularly welcome that they directly tackled common misconceptions and myths about COVID-19, which may have hindered our ability to get people on board to help stem the spread of the disease.

“The tradeoffs involved in combating the disease were very clearly articulated.  Health is of utmost importance, but the economic effects of combating the disease must not be ignored.  A poorer society is also a less healthy society, so we need to carefully consider all the welfare ramifications of different policies.”


Prof Dame Til Wykes, Vice Dean Psychology and Systems Sciences, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, said:

“Professor Chris Whitty discussed the balance of risks and really concentrated on the health risks of NHS overload and mortality.  But there is now evidence of the long term consequences of COVID-19 infection that affects people both physically and mentally.  Poor physical health can affect mental health making coronavirus infection the beginning of a toxic interaction that will also affect our economy.  Added to this is the more direct effects on mental health shown in previous pandemics and obvious in our own research data in this pandemic.  These dual effects will be curtailed by certainty over further rules, renewed trust in the government and a reduction in the overall transmission rate.”


Dr Simon Clarke, Associate Professor of Cellular Microbiology at the University of Reading, said:

“The update on the latest figures from the Chief Scientist and Chief Medical Officer provided a stark reminder of where we currently stand in terms of the accelerating transmission of Covid19 in the UK.

“This may sound like deja vu to many people, but it is vital for all of us to understand the risks to people’s lives, in every sense, either from the impacts of rampant spread of Covid19 or from strict measures to contain it.

“It’s becoming increasingly clear that at present we’re living our lives in a way that allows coronavirus to spread quickly through the population.  Unless we’ve collectively decided to change our position on preventing as many deaths as possible, then it suggests that stricter distancing measures will be necessary.

“It was also useful to hear the government’s leading scientists reinforcing the evidence: more than nine out of 10 people don’t have any immunity, the disease is just as dangerous as it always has been, and we still don’t have a vaccine ready to protect everyone.”


Prof Jackie Cassell, Deputy Dean, Brighton and Sussex Medical School, said:

“This was a sober and accurate statement of the state of the current epidemic, and of what can and should be done now to reduce the currently alarming rates of growth.  It was good to hear clarity about what exponential growth would mean for hospitalisations, deaths, and the NHS.  Importantly these include the impact of the NHS being unable to deliver other services.  There was rather less about the impact of lockdown itself, which has been notoriously difficult to quantify.

“Whitty was very clear about the basics of control – reduction of individual risk through personal behaviours, self-isolation if infected or a contact, and avoiding new links between households through Covid-secure workplaces and social behaviours.  Both were cautiously optimistic about vaccines, with initially targeted use by the end of the year and then wider use of vaccines currently in late stage development.  Little was said about testing and nothing about mass screening plans that have been recently been mooted.

“This statement will I think be welcomed and trusted by the public.  It gives clear advice on the importance of compliance with a wide range of basic measures such as covid-secure workplaces.   There was none of the bombast about future world-leading technical solutions that have undermined trust and distracted from the basics in recent weeks and months.”


Dr Amitava Banerjee, Associate Professor in Clinical Data Science and Honorary Consultant Cardiologist, Institute of Health Informatics, UCL, said:

“Whether as a clinician, a researcher or as a member of the public, it is not possible to watch the briefing from the Chief Scientific Officer and Chief Medical Officer without a mixture of anxiety but also of deja-vu from March and April of this year.  This briefing was a clear and succinct summary of what we know today in terms of facts and figures.  As outlined by Professor Whitty, there is a delicate balance between the three different impacts of the pandemic.  First, there are direct effects of COVID-19 through infection, particularly in vulnerable people.  Second, there are indirect effects on non-COVID-19 healthcare (e.g. cancer and cardiovascular disease) due to strains on the health system.  Third, there are effects on the economy from measures designed to curb infection rate, particularly lockdown.  The only way to contain all three of these effects is to keep infection rates as low as possible.

“There is no substantive evidence that increased testing is causing the increased cases, no evidence that there is increased immunity, and no evidence that any second potential wave will be milder.  Therefore we cannot claim that we do not know what the potential trajectory of further rises in infection rates will be.  There is a role and a responsibility for all of us, regardless of our individual risks, to reduce spread and reduce risk to vulnerable individuals.  Moreover, the advice from early in the pandemic that “test, trace and isolate” is the best defence, still holds true.”


Dr Shaun Fitzgerald FREng, Royal Academy of Engineering Visiting Professor at the University of Cambridge, said:

“Prof Whitty said ‘This is not someone else’s problem, this is all of our problem.’  I could not agree more strongly.  We can ALL affect the spread of the pandemic.

“If we all heed the ‘HANDS, FACE, SPACE & OPEN A WINDOW’ message, and limit interactions voluntarily, then we probably wouldn’t need more restrictions enforced.  We can all do our bit to suppress the spread, because the mechanisms for transmission are things we can affect.  However, if we choose not follow the message rigorously, it is difficult and we may need to see more restrictions. It is our choice.”


Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:

“The Chief Medical Officer and Chief Scientific Advisor have warned of a difficult few months ahead as the UK heads through the autumn and into the winter.  The data is reflecting expected patterns where cases in younger populations do later lead to hospitalisations and then increases in COVID-19 deaths, as the outbreak reaches more vulnerable individuals.

“One aspect they didn’t directly address is ‘long COVID’, where even relatively fit and healthy individuals are experiencing symptoms several weeks after they have cleared the initial infection.  These symptoms are common, occurring in 10-20% of non-hospitalised cases.  Severe fatigue and breathlessness among the most common symptoms.  The long-term burden of disease is still emerging but we can be fairly sure it will be extensive.

“The CMO and CSA also emphasised that around 8% of the population are thought to have antibodies against the infection, and these will likely fade over time and not be fully protective anyway.  Therefore, the herd immunity idea is fanciful and not something that can be part of any public health strategy.”



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