Failure to comply with COVID-19 containment measures penalizes the compliant as well

By Dr. Liji Thomas, MDReviewed by Emily Henderson, B.Sc.Dec 7 2020

The COVID-19 pandemic is now well into its second wave, and deaths are nearing or surpassing the spring peak as winter sets in over much of the northern hemisphere.

Image Credit: https://www.medrxiv.org/content/10.1101/2020.11.29.20240440v1.full.pdf

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources

A thought-provoking new study in the preprint server medRxiv* published in December 2020 discusses the importance of compliance with public health measures for containment of viral spread, as well as the consequences of not doing so. In so doing, this modeling study emphasizes the urgency of developing an effective game plan to achieve complete suppression.

The initial response to the presence of a global infectious disease threat was restrictions on individual mobility and social interactions, inevitably impacting economic activity. Side by side with this, the issue of noncompliance raised its head.

This is not new, however, having been encountered a hundred years ago, with the 1918 ‘Spanish flu’ pandemic, where many individuals refused to cooperate with public health interventions, including resistance to wearing masks – the so-called ‘mask slackers.’

Drivers of Noncompliance

With the current pandemic, there are some important differences that further drive noncompliance. For one, most adverse outcomes happen in the isolation ward or intensive care unit, leaving the public unaware of their gravity.

Secondly, there has been much change in the scientific understanding of viral transmission, mortality risk, and other sequelae. These two conditions have fostered the growth of misinformation, breeding immense confusion and mistrust in the public mind, as has been seen in the Ebola outbreak.

Thirdly, the virus causes many asymptomatic and presymptomatic infections. About 40% of the spread is from such cases, making containment impossible without general lockdowns and other very restrictive measures.

The virus has a high reproductive number, first reported being around 5.7 in the Wuhan days. With partial suppression, the number of infections will grow exponentially, as the second wave shows. Finally, transient immunity may allow multiple resurgences.

Aims of the Study

To investigate noncompliance and its impact further, the scientists attempted to answer three questions.

The first is to identify the circumstances that could benefit a large proportion of the population if they fail to comply with the recommendations. The second is to examine the effect of non-compliance on the possibility of completely stopping the spread of the virus. The last one is to estimate the cost of non-compliance to the compliant part of the population.

Noncompliance May Appear Beneficial

To answer the first question, they used a game theory approach exploring the scenarios in which the individual sees greater personal benefit from non-compliance than from compliance. They perceive this approach as very relevant today since many defend their noncompliance on the pretext of personal freedom.

They found that for many individuals, the perceived benefits of noncompliance were greater than for compliance.

“One can make the case that, using realistic estimates for risk of infection and risk of adverse outcomes given infection, compliance would still be a rational choice for the vast majority of the population.”

Noncompliance Promotes Endemicity

The other two questions were answered by a classical Susceptible-Exposed-Infected-Recovered-Susceptible (SEIRS) epidemiological model, setting the duration of immunity at 6-24 months.

The model suggests that if the viral spread is not adequately suppressed, and instead societies and governments choose to return to the pre-pandemic ‘normal’ too fast and too early, there will be a rapid increase in the number and rate of growth of infections. Transient immunity will allow more susceptibles to be added.

Low effectiveness of interventions must be compensated for by very high compliance. In just one situation, the scientists discuss an intervention which is 50% effective at preventing infection, but which is complied with by 95% of the population. This results in dampening the fluctuations in the rate of transmission.

If a highly effective (65% or more) intervention is introduced, and if compliance is high, 80% or more, the pandemic will be suppressed even while conditions return to pre-pandemic levels. The interplay of these factors above a threshold determines whether next year will see less than 1 million cases or hundreds of millions, depending on these two factors.

To answer the third question, the more people there are who fail to comply, the greater is the total risk to the compliant population compared to the former. As non-compliance increases, the fluctuations become more variable, as does the risk to the compliant segment of the population over time.

Compliance Becomes Unrewarding

Failing short-term suppression, either due to failure to intervene effectively or because of waning immunity, the virus will become endemic. For instance, even if compliance is 100%, but the intervention is only 50% effective, the prevalence will reach a steady state. This means a compliant individual reaps a smaller benefit with a less effective intervention than for a highly effective one since universal compliance with the latter would suppress viral spread completely.

If long-term suppression of the virus does not happen, the disease will persist at a high level, but almost successful suppression is very far from being as rewarding as total suppression.

“The marginal cost in terms of yearly cases for failures to suppress disease is highest for near-success cases and is steeply dependent on the degree of compliance.”

What are the Implications?

For complete suppression, intervention and compliance must meet a minimum correlative balance, with at least 60% efficacy and a high degree of compliance. Nonetheless, a large number of noncompliant individuals can sabotage even a very effective intervention. Thus, even a 99% effective vaccine will not lead to suppression if 20% or more are not willing to accept it.

In short, the researchers say, “Individuals optimizing their own self-interest can justify their actions in terms of their own perceived cost-benefit.” Thus, appealing to altruism in terms of protecting high-risk individuals may be an ineffective plan to increase compliance. Younger individuals have a low risk of serious illness or death, and even others may view themselves as being at lower risk of infection or poor outcomes than the average.

Paradoxically, some individuals justify their non-compliance based on fear of a poor outcome, since they feel that they are already likely to die, and this will not be altered by their compliance.

The researchers call the result of such non-compliant attitudes a Tragedy of the Commons situation, where the common outcome is poor because of individual selfish choices. They comment, “What makes Tragedy of the Commons situations particularly intractable is that it usually only takes a small proportion of individuals optimizing for their own self-interest to create devastating externalities (non-self-caused) for the rest of the population.”

Suggested Actions

As such, this study speaks against the practice of leaving such choices to the individual. Instead, they suggest, the cost to the individual vs the benefit of noncompliance should be emphasized, such as the risk of age-independent long-haul symptoms and damage to the lungs, heart, brain, and other vital organs, even after asymptomatic infection.

Secondly, the risk of infection should be accurately communicated. Public health messaging at the community level should create trust and bonding between individuals and public health/government experts, highlighting the adverse effects of behavior that impacts others in society negatively.

Fining the noncompliant is one way to put part of the cost of non-compliance on the person responsible. A strong sense of the need to conform to societal norms rather than purely individualistic desires underlies high compliance in many countries, unlike the USA. Passive interventions such as improving building ventilation is another way to improve compliance.

The researchers conclude with three takeaway messages: complete suppression is the goal; public health policies must emphasize compliance for long- and short-term suppression, and make noncompliance more costly than compliance to encourage the latter; and interventions with lower effectiveness are not the whole solution, while they may contribute to it, making it mandatory to look for very effective interventions.

This news article was a review of a preliminary scientific report that had not undergone peer-review at the time of publication. Since its initial publication, the scientific report has now been peer reviewed and accepted for publication in a Scientific Journal. Links to the preliminary and peer-reviewed reports are available in the Sources section at the bottom of this article. View Sources