COVID-19: Winter has Come

[This text has been written by Carlos Chaccour, Assistant Research Professor at ISGlobal and Chief Scientific Officer of BOHEMIA; and Julie Chaccour, immunologist and medical editor]

The 1918 influenza pandemic infected one third of the world's population and caused 50 million deaths. There were three distinct waves. The second occurred in autumn 1918 and caused the most deaths. We are still in time to avert the same pattern repeating in the COVID-19 pandemic.

Three waves of death during the pandemic: weekly combined influenza and pneumonia mortality, United Kingdom, 1918–1919. The waves were broadly the same globally. Taubenberger JK, Morens DM. 1918 Influenza: the Mother of All Pandemics. Emerg Infect Dis. 2006;12(1):15-22., CC BY.

History has taught us that in the absence of a vaccine, epidemic spread of a disease like COVID-19 only stops once a significant proportion of the population has recovered and developed immunity.

Until an effective vaccine is widely available there will be fundamentally two kinds of people: those who have recovered (and hence have some degree of immunity¹) and those who are still susceptible to acquiring the disease.

The 1918 influenza pandemic infected one third of the world's population and caused 50 million deaths. There were three distinct waves. The second occurred in autumn 1918 and caused the most deaths. We are still in time to avert the same pattern repeating in the COVID-19 pandemic

Europe, and particularly Spain, successfully delayed the spread of COVID-19 during the summer of 2020 thanks to lockdown measures adopted in the spring. Viral transmission was heavily suppressed but, by definition, it could not be interrupted entirely given that the virus is present around the world.

Figure made by Joe Brew.

The current trend shows a major second wave inexorably approaching. The pattern is repeating all around Europe: outbreaks start among young adults and then transmission spills over into other age groups. It is the elderly that are at highest risk of severe disease and death. It is predominantly the management of elderly patients and those with comorbidities that overwhelms the health system, particularly critical care, which further drives excess deaths in those who would normally benefit from these specialized units.

Figure made by Joe Brew.

Figure made by Joe Brew.

As the winter approaches, so do seasonal influenza, respiratory syncytial virus, rhinoviruses and other respiratory tract infections that will put further pressure on the health system. All points towards a massive wave of cases and deaths in the coming months. This is largely not avoidable.

Source: Heatmaps of COVID Cases in England.

There is a 2-3 week lag between cases and hospital admissions, then between hospital and ICU admissions, and finally between ICU admissions and deaths. Given the current trend in cases in all ages, but particularly among the elderly in Spain, a surge in deaths in the next 4-6 weeks is expected.

 There are several different scenarios for the future of the COVID-19 pandemic, and some of these are consistent with what occurred during past influenza pandemics. Source: COVID-19: The CIDRAP Viewpoint. Part 1: The Future of the COVID-19 Pandemic: Lessons from Pandemic Influenza. Figure 1. 30 April 2020.

Suppression strategy scenarios for Great Britain showing ICU bed requirements. Source: Report 9: Impact of non-pharmaceutical interventions (NPIs) to reduce COVID19 mortality and healthcare demand. Imperial College of London. Figure 3. doi.org/10.25561/77482.

Actions taken today can mitigate this coming wave, but not fully avoid it. Deaths will reduce in parallel with transmission, but with a lag of 6-8 weeks, as observed after the emergency measures taken on March 14. Delays in action are expected to have three effects:

1. The peak of the wave might be higher.
2. The duration of the wave might be longer.
3. Any reactive measures taken later will have to be stronger and longer lasting.

From the epidemiological point of view, the actions to be taken are clear and they are all imperfect tools implemented in an imperfect way, yet proven efficacious if this is done consistently:

1. Increase hospital and critical care capacity.
2. Conduct high numbers of tests leading to early diagnosis, contact tracing, isolation and quarantine.
3. Reduce transmission with non-pharmacological measures including social distance and masks.
4. Plan for optimal use of emerging tools including new diagnostics, drugs and vaccines.
5. Strive for transparency and effective communication to facilitate compliance.

Figure made by Joe Brew.

Even though the winter is imminent, we can still mitigate some of the hardest consequences of the coming wave. For this, we must understand the concept of social budget. Imagine your salary is suddenly cut in half and you need to budget very well for your weekly shopping. It would be foolish to spend it all on chocolate and beer and wiser to first cover your nutritional needs and use any surplus for snacks and alcohol. In the same way, our now restricted social budget should cover first the pillars of society in the short and long run.

Even though the winter is imminent, we can still mitigate some of the hardest consequences of the coming wave

Some potential optimization of our restricted social budget include:

• Anticipate the broadening of already existent social divisions as it is the poor who will suffer the most enduring health and economic consequences of the pandemic and create measures to address them.
• Provide parents, but particularly mothers (who carry out a majority of domestic and parenting tasks, as studies show), with the necessary tools to withstand setbacks caused by the difficulties to reconcile working from home with child care.
• Recognize the primary economic importance of education, both driving current production by allowing parents focused time and preparing tomorrow's labor force.
• Identify strategies that can protect both the health and the social well being of the elderly and other vulnerable groups that cannot be expected to remain sheltered indefinitely.
• Understand the negative health consequences of restrictive measures and develop strategies to alleviate them.
• Avoid misinformation and facilitate compliance with the sacrifice imposed upon the population by developing strategies for scientists, policy makers and politicians to communicate effectively.
• Provide economic assistance to those who are obliged or recommended to quarantine so as to ensure they are able to comply with public health measures.

We know more about the lethal consequences of acting too late. Let’s act quickly, precisely, and boldly to minimize death and suffering and protect the most vulnerable

Winter is coming, and it is time to think about our social budget. The second wave does not have to be like the first. We know more about this virus, and we know more about the social and economic externalities of hard lockdowns. We also know more about the lethal consequences of acting too late. Let’s act quickly, precisely, and boldly to minimize death and suffering and protect the most vulnerable.

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¹ Provided there is long-lasting post-infectious immunity and no escape strains.