Low incidence strategy for control of COVID-19

By Sam HancockReviewed by Danielle Ellis, B.Sc.Jan 13 2022

The coronavirus disease 2019 (COVID-19) pandemic has been ongoing for over two years now, and lack of compliance, vaccine hesitancy, and apparent apathy have grown over time. This has reached the point where some public figures have openly argued for the reduction of non-pharmaceutical interventions, even in cases where this would increase disease incidence. In a study published in The Lancet Regional Health – Europe, researchers from the Institute for Advanced Studies in Vienna argued for the benefits of a low incidence strategy to control the disease.

Study: The benefits, costs and feasibility of a low incidence COVID-19 strategy. Image Credit: pang_oasis/Shutterstock

The study

The researchers argued that rapid reduction of non-pharmaceutical interventions (NPIs) leads to rapid increases in disease incidences, even in countries with high vaccination rates. Both Singapore and Israel showed rising rates following the removal of some NPIs. The emergence of variants of concern (VOCs) with the ability to evade immune response only exacerbates the situation. As test and trace programs can be rapidly overwhelmed, they can quickly reach the point where more intense restrictions are required before their removal.

While some governments initially argued about the value of allowing a high incidence of disease to develop herd immunity, the scientists caution against this approach. They argue that high disease incidences cause the most harm to already vulnerable populations, including the disabled, economically deprived, or socially marginalized.

These populations are already less likely to be vaccinated and will find it more difficult to access programs and campaigns that could help them. It also excessively harms those who cannot be vaccinated for reasons beyond their control or those who show poor immune response following the vaccination. They also point out arguments that could influence the more hard-hearted: High incidence negatively impacts the workforce and productivity.

Isolation and illness remove one worker from the population and put a greater burden on the surrounding workers. This is likely to increase the rate of burnout, seen extensively in healthcare workers. Not only is the infected worker removed from the workforce, but any individuals who live with them will also need to isolate, reducing efficiency even further. This problem is compounded in education, as both children and educators can be forced to quarantine, harming the future generations as well

The scientists then raised a point often raised by scientists but rarely drives any political debate. A high incidence alongside only a portion of the population gaining immunity – either natural or from vaccination – does not eliminate disease. Rather, it simply provides an evolutionary pressure to escape that immunity and spread even further. While this could easily occur in a country-wide population, it has also clearly been seen as more and more variants with at least some immune evasion continue to arise, more often from less vaccinated populations. This can be even more difficult to deal with as vaccinated individuals are likely to be less cautious than before they were vaccinated.

The researchers argued for a low incidence strategy based on three main points: First, it is easier to control transmission with track and trace systems with low incidence. Second, as vaccination rates increase, less NPIs are needed to keep reproduction rates low. Third, the harms caused by NPIs are lessened as the most restrictive measures, such as lockdowns, are not needed.

As a study funded by the European Commission, it is not unexpected that they call for pan-European commitment. Still, this call is backed up by strong arguments, such as the ease of an early warning system, coordinated NPIs to avoid transmission across borders swinging wildly in both directions, and the ability to share vaccines and prevent the emergence of new variants.

The question of trust is then raised. The scientists point out that not only do NPIs require communication and timing between countries, but a significant amount of public trust. Unfortunately, this has been waning over the last few years. Extensive restrictions, failures in communication, and the perception of a failure to control the pandemic have resulted in falling public commitment and reduced compliance with restrictions. The scientists suggest that the support of locally respected persons and communities and open and unambiguous communication should help.

Conclusion

While the pandemic is not yet over, an end is in sight. The author's commitment to a low incidence strategy conflicts with the apathy and fatigue displayed by many individuals who have begun to grow skeptical of pandemic control measures. Hopefully, if the approach lauded by the authors is followed, the disease can be brought under control with minimal future casualties.