Reduction of COVID-19 incidence across Europe in spring 2021 led to significant relaxation of restrictions in summer, despite the emergence and spread of the more transmissible Delta variant. As expected, this led to a renewed increase in incidence. How should Europe act, what strategies should it adopt, and what specific risks should it consider moving forward?1 These questions become even more pressing, since emerging data indicates the Delta variant is more infectious and partially evades immune response. Europe needs a coherent and effective strategy, before schools fully reopen and the transmission of SARS-CoV-2 further increases due to seasonality in autumn.
Two opposing strategies are considered: 1) continue to rapidly lift restrictions, assuming the combination of past natural exposure and current vaccination coverage would allow a high incidence to continue, without overburdening healthcare systems; or 2) lift restrictions at the pace of vaccination progress with the core aim to keep incidence low, given this effectively and efficiently controls the pandemic via test-trace-isolate (TTI) programs.2,3
Given immunization levels as of August, 2021, the first strategy can lead to an incidence of several hundred per million per day, whereas the second would require an incidence of well below one hundred. Such a discrepancy of incidence poses considerable friction to European cooperation, economy and society: high incidence in one country puts the low-incidence strategy in a neighboring country at risk. Because of this conflict of interest, some countries impose testing and quarantine requirements, hampering international exchange. Thus, either strategy can only work effectively if European countries stop acting as if they could fight the pandemic on their own.
To facilitate cross-border travel, the European Union’s Digital Covid Certificate (EU DCC) was introduced. However, no vaccine is completely effective at preventing virus transmission. Therefore, the implementation of the EU DCC must be accompanied by systematic evaluation regarding its contribution to the spread of present and future variants of concern (VOCs).4 The development of a European strategy for testing travelers and commuters is therefore warranted.5
The advantages of a low incidence are known and include (1) less mortality, morbidity and Long COVID-19, (2) solidarity with those not yet protected, (3) lower risk of new VOCs emerging and spreading, (4) increased feasibility of comprehensive TTI, (5) less workforce in quarantine and isolation, including those in healthcare, (6) ensuring schools and childcare remain open during the coming autumn-winter season.6 In contrast, a high incidence might still overwhelm hospitals and intensive care units in some countries.
Given the clear benefits of low incidence, the insufficient vaccination coverage in many European countries, uncertainties regarding child vaccination, and the time required for full immunization of adolescents, we recommend that all European countries act together to achieve low incidence, at least until everyone has had the opportunity to get vaccinated. A high incidence in one country challenges the pandemic response for others, in Europe and across the world. Maintaining low incidence represents an act of solidarity, and becomes easier with the advantage of an increasing vaccination coverage.
To improve measure effectiveness, three further challenges must be overcome: (1) vaccination availability, access, and hesitancy; (2) the widespread misconception that freedom would be maximized when ignoring high incidence; it has been recognized that low incidence facilitates containment and safeguards the freedom of all, including the most vulnerable; and (3) the lack of a coherent pandemic response and communication strategy; perceived risk, motivation and health literacy are important predictors of health-seeking behaviour and adherence to measures; public trust must be maintained through timely, consistent and persistent communications, including systematically developed counterspeech for misinformation.
We have yet to overcome the pandemic, but an end is conceivable: Restrictions can be lifted when high vaccination coverage is reached, and if vaccines remain highly effective against VOCs. However, until then, the goal should be to minimize economic and societal costs for Europe and for the world. Maintaining and communicating a clear strategy is key; Pan-European coordination and common goals across countries are more important than ever.
The interactive Excel sheet to calculate ICU admissions can be downloaded here