Survey to determine the main aspects likely to influence the pandemic in Europe

Almost two years since Europe's first confirmed COVID-19 case, the region is still struggling to contain the spread of the disease, with no clear idea of what the future holds. To combat this uncertainty, researchers supported by the EU-funded EpiPose, PERISCOPE and CORESMA projects set out to systematically assess the factors likely to affect the pandemic's course in Europe and predict how it may evolve.

The survey was based on questionnaires with open-ended questions focusing on epidemiology, virology, public health and social science, directed at experts throughout Europe. The resulting study combines epidemiological aspects with economic, social and health-related consequences to provide a more holistic perspective on the pandemic's future course.

According to the study, the pandemic's development will strongly depend on population immunity, variants of concern (VOCs) and how the public responds to public health measures. Two major contributors to population immunity are vaccination and so-called natural immunity resulting from prior infection with SARS-CoV-2 and likely from prior exposure to other coronaviruses. "The fraction of those who are naturally immune in the population varies widely between European countries. However, in all countries the majority of the population remained susceptible to infection," the authors write.

Vaccine uptake in Europe is "an ever-changing situation," ranging from high initial acceptance amongst older and vulnerable people to wariness following reports of possible links to rare side effects and lower willingness to get vaccinated amongst younger age groups. However, as long as population immunity hasn't been reached, appropriate restrictions need to be maintained to stop the virus from spreading. "In the short term, many people remain unvaccinated, VOCs continue to emerge and spread, and mobility and population mixing are expected to increase. Therefore, lifting restrictions too much and too early risk another damaging wave. This challenge remains despite the reduced opportunities for transmission given vaccination progress and reduced indoor mixing in summer 2021," according to the study.

What to expect in late 2021 and beyond

Increased indoor activity in autumn might speed up the virus' spread, necessitating the reintroduction of public health measures—possibly too late. It ultimately all depends on vaccination levels. As the study reports, "countries with … high vaccine uptake can, at worst, expect only modest waves of COVID-19 over the winter" while maintaining moderate public health measures. In contrast, unless appropriate measures are taken, countries with a lower level of vaccination coverage will experience more severe waves.

So will we see the back of the pandemic in the next three to five years? According to the study, it's unclear whether SARS-CoV-2 can be eradicated in the long term. Nevertheless, eradicating the virus would necessitate "global political commitment and unified and uniform public assent that eradication is the overarching target." If children are also vaccinated, some countries might achieve high enough vaccination rates to sustainably prevent local transmission. In countries with insufficient or too heterogeneous immunity, recurring local and seasonal outbreaks of the virus are expected.