"UK Warned of Winter Resurgence in COVID-19" and "It'll be Over by Christmas" have been the completely contradictory headlines in the UK this week. (1) (2)
Perhaps a more accurate headline would be "COVID-19 may come back in the winter, but it may not" or "COVID-19 could be a problem this winter unless we all continue to take steps to control it".
The focus does now need to shift to the winter, a time when the flu virus is known to circulate through the population and life has to move indoors as the weather deteriorates. It is wise to plan for the worst whilst hoping for the best.
In the piece here I discussed the possibility of a second wave of infection. Since writing it Europe has continued to ease out of lockdown and there have been no nationwide resurgences of infection but smaller outbreaks, including one in Leicester in the UK, have required localised lockdowns to keep the virus under control.
Nobody can give an exact answer on whether the UK, along with the rest of the northern hemisphere, will see a resurgence this winter. The fact that the virus has spread globally, and therefore through every climate and season possible, may reflect a virus that cares little for ambient weather conditions. Or it may be more indicative of the fact any new virus can spread unabated through a non-immune world until finally settling into a recognised pattern where it will appear only in certain seasons.
Scientifically we would expect winter to be a more vulnerable time since since this is the peak period when other respiratory viruses circulate through the population. It will also be harder to identify people with COVID-19 infection against a backdrop of the normal winter coughs and colds and flu-like illnesses. People remain indoors more in winter making person to person transmission more likely.
The outcome may be determined by how large the number of people infected with COVID-19 still is as we go into winter, the larger the number the more susceptible to a winter resurgence we will be. This could be mitigated by continued social distancing measures and ongoing local lockdowns where an increase in cases is seen.
The Worst Case Scenario.
The most dire warnings have been that the UK will experience a winter second wave of COVID-19 three times worse than what it has seen thus far.
Members of the Academy of the Medical Sciences released a 79 page report on 14 July 2020 in which they warned that the UK must prepare for a potential new wave of coronavirus infections this winter that could be more serious than the first. The report predicts "A reasonable worst-case scenario would see the reproduction value rise from about 0.7-0.9 today to 1.7 in September, causing a peak in hospital admissions and deaths in January and February 2021 similar to or worse than the first wave this year." (3)
(For further explanation of the reproduction value, or R number, of a disease click here for a previous blog piece on the subject)
The Academy fears a lethal interaction between winter overcrowding, flu and COVID-19 could lead to an extra 120,000 deaths in the UK over the next 12 months. This estimate of deaths is nearly three time the 44,830 already suffered in the UK. However, researchers also report that steps such as increased testing & tracing and continued social distancing could help mitigate the risk.
Professor Stephen Holgate, from University Hospital Southampton NHS Foundation Trust, said: “This is not a prediction, but it is a possibility. The modelling suggests that deaths could be higher with a new wave of COVID-19 this winter, but the risk of this happening could be reduced if we take action immediately. With relatively low numbers of COVID-19 cases at the moment, this is a critical window of opportunity to help us prepare for the worst that winter can throw at us.” (4)
It should be noted that epidemiological models are not flawless. They are important tools for planning responses to situations like the current pandemic but different models can reach conflicting conclusions even when they are studying the same problem. Assumptions have to be made about factors such as asymptomatic transmission or potential treatments. The Academy of the Medical Sciences report does not take into account for example the breakthrough made by the role of dexamethasone in reducing the death rate of COVID-19 or the possibility of a vaccine becoming available. (More information on dexamethasone can be found here.)
All mathematical models operate with a degree of uncertainty, especially when looking at a new disease where much is still unknown both about the virus and the pattern of illness it is causing and this should be remembered when studying worst case scenarios. (5)
Best Case Scenario.
The ultimate best case scenario would be complete eradication of the virus but this is not realistic. Smallpox is the only human disease that has been successfully eradicated and it took 20 years to do so. Efforts to eradicate polio, measles and malaria are yet to be successful and these are diseases we have vaccines and/or treatments for. (6)
The worst case scenario reports do not take into account any interventions that modify the progression of COVID-19. Behavioural interventions such as social distancing and mask wearing along with local lockdowns of disease outbreaks will affect the outcome. Plus the advances in treatments such as the use of dexamethasone in the seriously ill will reduce the mortality from COVID-19.
Work is continuing on a vaccine for COVID-19 and there are encouraging signs on the Oxford vaccine. The vaccine is discussed in detail here and here in the blog but the outcome of its Phase I trials, released on 20 July 2020, are promising with it appearing to be both safe and provoking a good immune response against COVID-19. However one of the lead researchers, Professor Sir John Bell of the University of Oxford, has warned that "The reality is that this pathogen is here forever, it isn't going anywhere. Look at how much trouble they've had in eliminating, for example, polio, that eradication programme has been going on for 15 years and they're still not there. So this is going to come and go, and we're going to get winters where we get a lot of this virus back in action." (7)
Assuming a vaccine is not available for this winter, it may be possible to keep the R number from going above 1.1 if robust surveillance and local lockdowns continue in conjunction with other measures. One very important measure will be to limit the impact of flu by ensuring there are adequate supplies of both flu vaccine and anti-viral drugs used to treat flu.
Professor Anne Johnson of the Infectious Disease Epidemiology at University College London explains that “We don’t know how COVID-19 will interact with flu. An adequate supply of the flu vaccine will be vital in the autumn. Those who are considered vulnerable to flu, people working in healthcare settings and schoolchildren should all receive the vaccine."
With tests available for flu as well as COVID-19, Professor Johnson says the UK will need to scale up testing for both so that "people will know which virus they have and so their care can be managed appropriately." (8)
Dr Alison Pittard, the Dean of the Faculty of Intensive Care Medicine, warns, “People might think COVID-19 is over with, why do I have to wear a face mask? But it isn’t over. We still have COVID-19 patients in intensive care. If the public don’t physically distance and don’t wear face coverings we could very quickly get back to where we were earlier this year.” (9)
(Facemasks become compulsory in UK shops on 24 July 2020 and you can read more about why in the piece here.)
In Conclusion.
It seems highly likely that COVID-19 will be with us for the foreseeable future.
As lockdown is eased over the summer there is a real risk of complacency as people view life as returning to normal but the next few weeks and months are crucial in controlling the virus. The virus itself has not gone away and if we abandon all the measures that have controlled it thus far it will spread again.
(1) https://www.bbc.co.uk/news/uk-53488142
(2) https://www.independent.co.uk/voices/boris-johnson-coronavirus-infections-deaths-christmas-care-homes-a9624661.html
(3) https://acmedsci.ac.uk/more/news/prepare-now-for-a-winter-covid-19-peak-warns-academy-of-medical-sciences
(4) www.acmedsci.ac.uk/coronavirus-winter-challenges-public-dialogue
(5) https://www.nejm.org/doi/full/10.1056/NEJMp2016822
(6) https://en.wikipedia.org/wiki/Eradication_of_infectious_diseases#Rinderpest
(7) https://www.independent.co.uk/news/uk/politics/uk-winter-coronavirus-vaccine-john-bell-cases-deaths-a9595991.html
(8) https://www.newscientist.com/article/2248691-a-bad-uk-winter-could-cause-120000-hospital-deaths-linked-to-covid-19/
