Klaus Prettner, Simiao Chen, Michael Kuhn, David Bloom 04 January 2021
Proponents of the ‘herd immunity’ approach to COVID-19 argue for a largely uncontrolled outbreak in the low-risk population, while protecting the vulnerable, to achieve natural immunisation at minimal economic cost. In contrast, others favour fighting COVID-19 with all possible means, including lockdowns. This column describes simple, effective, and low-cost policy measures designed to fight the spread of COVID-19 that should be amenable to both camps.
As many countries faced the second wave of COVID-19 in the autumn of 2020, a debate emerged on the best way to cope with a pandemic that has caused more than 80 million confirmed infections and is associated with over 1.7 million deaths worldwide as of 27 December 2020.1 Some analysts and policymakers worry about the negative economic and general health consequences of mandated lockdowns and other measures against the spread of the disease and favour the ‘herd immunity’ approach. This approach passively allows a largely uncontrolled outbreak in the low-risk population, while actively protecting the vulnerable, with the ultimate goal of achieving immunity in such a large portion of the population that the spread of the disease eventually ceases. In contrast, other analysts and policymakers suggest fighting the spread of the disease by all possible means, including lockdowns. This latter approach aims mainly to flatten the infection curve to avoid the crowding of hospitals and intensive care units – and thereby a substantial increase in mortality – until safe and efficacious vaccines become widely available. The contrast between the Great Barrington Declaration1 from the advocates of the herd immunity approach and the John Snow Memorandum (Alwan et al. 2020) from those who are more concerned with the negative health and economic consequences of uncontrolled COVID-19 highlights the diverging views that characterise this domain.
In this column, we aim to describe effective and comparatively low-cost policy measures against the spread of COVID-19 that should be amenable to both camps (see Bloom et al. 2021 for more general descriptions of the trade-offs that policymakers face in a pandemic). The policy measures we describe minimise economic, physical, and mental harm, while at the same time effectively reducing infection rates according to empirical evidence. These measures, particularly when combined and enacted early, reduce infection rates substantially and have the potential to reduce the reproductive number of the virus below 1.0, which implies that the disease would peter out. While this result is by no means guaranteed – particularly when new strains of the virus, such as the one identified in South Africa and in the UK late in 2020, are more infectious – the policy measures we describe would at the very least reduce the time during which more drastic measures are necessary. In the following, we list low-cost, high-impact policy interventions along with their rationale and references to recent empirical findings on their usefulness. In particular, we draw attention to:
1. Ensuring the physical distancing of people residing in different households. While one metre is often recommended as the minimal distance, COVID-19 transmissibility continues to decrease significantly with greater distances over and above one metre (Chu et al. 2020).
2. Investing massively in expanding the number of tests, particularly for groups at high risk of COVID-19 infection and of transmitting the disease such as doctors and nurses, nursing home staffs, workers at meat processing plants, teachers, cashiers, and employees in public transportation. An important feature of this intervention is making sure that those who want to be tested do get tested within a short period of time – ideally in dedicated testing facilities separate from other patients and outside of buildings with indoor waiting areas. Testing and contact tracing are simple and harm-minimising ways to break infection chains (Kucharski et al. 2020). While this is widely acknowledged, many countries still have shortfalls of test kits, laboratory capacity, and contact tracing personnel, even as they spend enormous amounts on containing the economic fallout of the disease’s rapid spread.
3. Provided that enough testing capacity is available for the groups at high risk of infection or high risk of spreading the disease, massive testing on a large scale (at the city or even the country level) is likely to be a less harmful approach than local or country-wide lockdowns (Taipale et al. 2020).
4. In conjunction with points 2 and 3, providing community isolation centres for asymptomatic, mild, or moderate COVID-19 patients who are unable or not safe to isolate at home, such as people who live in crowded conditions or those who need some basic care and treatment (CDC 2020). The risk of intra-family transmission is very high and is, indeed, currently the largest source of new infections in many countries (Liu et al. 2020). About 66% of hospitalised patients in New York were infected at home, while 75–80% of all clustered infections were within families in China (CNBC 2020, WHO 2020). Adopting facility-based isolation in community isolation centres could help decrease the rate of infections within families (Chen et al. 2020a, Dickens et al. 2020).
5. Mandating the use of face masks in all indoor places where people interact and aiming to provide – free of charge – high-filtration FFP2 and FFP3 masks (with minimum filtration efficiencies of 94% and 99%, respectively) to those who must interact directly with others. This includes, for example, teachers, cashiers, public transportation employees, and attendees at meetings that cannot be held distantly (Mitze et al. 2020, Peeples 2020, Chu et al. 2020).
6. Prohibiting all unnecessary indoor gatherings and facilitating outdoor events with strict application of social distancing measures and mask mandates until working vaccines become widely available (Chen et al. 2020b, Nishiura et al. 2020).
7. Implementing working from home policies wherever possible (e.g. Alipour et al. 2020) to reduce contacts at the workplace. Whenever working from home is not possible, implementing staggered work schedules and school starting times to avoid rush hours and the crowding of public transportation.
8. Improving ventilation – particularly displacement ventilation – and ensuring effective distancing measures in places that people cannot easily avoid, such as supermarkets, public transportation, factories, and whenever working from home is not possible (Bhagat et al. 2020; Chu et al. 2020, Morawska et al. 2020). Inside these facilities, distancing measures could comprise a maximum number of people allowed per square metre, one-way movement regulations, plexiglass barriers, and dedicated waiting areas in queues. Ventilation is particularly important as COVID-19 may worsen in autumn and winter as people spend more time inside than outside (Chen et al. 2020c).
9. Aiming for disinfection with ultraviolet light (at least once per day) of indoor areas that are frequently visited by different persons (Raeiszadeh and Adeli 2020 and the references therein). This should be combined with the frequent sanitisation of door handles, elevator buttons, and surfaces in common areas such as bathrooms.
10. Swiftly imposing travel restrictions in and out of geographic areas with high infection rates or the emergence of new and more infectious or more deadly strains of the virus to avoid (or at least delay) spreading the disease to other areas and countries (Chen et al. 2020d, 2020e).
11. Applying a differentiated policy for schools and universities with mandated distance learning at universities and for older pupils who are more infectious but need less personal interaction with instructors or care from parents. At the same time, kindergartens and primary schools for younger pupils who are less infectious but need more personal interaction with instructors or parental care could remain open. This approach would reduce the risk of infection in the classroom as well as the economic harm of such measures, which can be quite significant (Rajmil 2020, Psacharopoulos and Patrinos 2018, Viner et al. 2020). Under conditions in which there is an elevated risk of transmission of new strains of the virus to which children are relatively more susceptible, distance learning of all age groups will be a necessary choice. This, however, would need to be thoroughly prepared to ensure that children of socially disadvantaged households are not left behind.
12. Facilitating zinc and vitamin D supplementation at generally recommended levels. Deficiencies of these nutrients are associated with more severe disease progression (Castillo et al. 2020, Meltzer et al. 2020).
13. Providing more resources for large-scale clinical trials on the effectiveness of low-cost interventions such as zinc and vitamin D supplementation but also the use of oral rinses (which have been shown to deactivate the SARS-CoV-2 virus quickly in laboratory studies (Meister et al. 2020) and of MMR vaccination, where findings crudely suggest cross-immunity between mumps and COVID-19 (Gold et al. 2020).
14. Encouraging the use of technologies such as digital apps for contact tracing, which are effective in identifying the contacts of COVID-19 cases if their use is widespread (Braithwaite et al., 2020, Kucharski et al. 2020). However, concerns regarding data and privacy protection need to be taken seriously to increase the adoption of these apps.
Overall, early and decisive implementation of this portfolio of policies is of the utmost importance in responding to the COVID-19 pandemic. Ideally, these policy measures should be implemented when the number of infections is still comparatively low, such as in summer (Chen et al. 2020c, 2020f), to reduce the infection base from which infections start to rise again in autumn and winter. While many countries in the Northern Hemisphere neglected such policies last summer, their adoption could help avoid (or at least postpone the necessary introduction of) lockdowns with their negative economic and social repercussions. The additional time thus bought could be used to build up medical capacities and supplies, particularly those related to vaccine manufacture, the expansion of intensive care capacity, and the production and widespread distribution of protective gear.
Although plenty of evidence now supports such policy measures, valuable time was lost at the beginning of the pandemic because the absence of evidence of an effect was mistaken for evidence of the absence of an effect. For example, early in the pandemic, the World Health Organization was reluctant to recommend international travel restrictions and the widespread use of face masks (partly out of concern that health care workers might run out of such necessary supplies), while hesitating to acknowledge the possibility of the airborne transmission of COVID-19 because scientific evidence was lacking. However, when the costs of erring by omitting these policies are so high, as in the case of a pandemic, the safer choice would have been to act decisively – pre-emptively – even absent rigorous evidence. The downside of enacting the aforementioned measures is rather insignificant compared with having to fight a full worldwide disease outbreak with comprehensive lockdowns and other similarly drastic measures.
SOURCE (and references)