OBJECTIVES : To assess the disparity in epidemiology of COVID-19 during the first and second waves of pandemic in EU-5 countries.

METHODS : Embase and Medline were searched from Dec-2019 to June-2021 for articles assessing the epidemiology of COVID-19 in EU-5 countries during first wave and second wave of pandemic. A single reviewer screened and extracted data for targeted literature review.

RESULTS : Of 3189 records screened, nine studies (n=73,525) were included which focused on Spain (n=3), Italy (n=3), Germany (n=1), UK (n=1), and France (n=1). The first wave occurred between March-August 2020, February-September 2020, March-June 2020, and February-July 2020 in UK, Italy, Spain, and Germany, respectively. The second wave existed between September-October 2020, July-October 2020, February-April 2020, and July-December 2020 in Italy, Spain, France and Germany, respectively. The cumulative incidence of COVID-19 infections in Spain was significantly higher during second wave than first wave (679 vs. 387/100,000). However, the case fatality rate was lower in second wave than in first wave (0.15 vs. 0.025). Also, the fatality rate was significantly higher in first wave compared to second wave (24% vs. 13.2%) in Spain and in the UK (32.3% vs. 16.4%). While there was no significant difference in mortality between the two waves in Germany (18% vs 20%). Limited data for only first wave was available for France. The peak incidence of cases was recorded between March-April 2020 in France, the COVID-19 related mortality during first wave was 20%.

CONCLUSIONS : COVID-19 incidence was higher during the second wave in Italy, while the fatality rate was higher in the first wave in Italy, UK, and Spain. However, time frame of COVID waves varied across the countries/studies despite its colloquial use. Therefore, future studies are required to reach a consensus on wave definition and explore the disparities between the pandemic waves’ definitions.