The Effect of COVID Certificates on Vaccine Uptake, Health Outcomes, and the Economy

Quantitative estimation of the impact of COVID certificates in France, Italy and Germany on vaccine uptake, health outcomes ( hospital admissions and deaths) and economic activity (GDP). In the COVID‐19 pandemic, governments have used various interventions,1,2 including COVID certificates to prove vaccination, recovery, or a recent negative test and required to access shops, restaurants, and education or workplaces.3 While arguments for and against COVID certificates have focused on reducing transmission and ethical concerns,4,5 the incentive effects of COVID certificates on vaccine uptake, health outcomes, and the economy has not yet been investigated. To estimate these effects, we construct counterfactuals based on innovation diffusion theory6 for France, Germany, and Italy. We estimate that the announcement of COVID certificates during summer 2021 led to increased vaccine uptake in France of 13.0 (95% CI 9.7‐14.9) percentage points (p.p.) of the total population until the end of the year, in Germany 6.2 (2.6‐6.9) p.p., and in Italy 9.7 (5.4‐12.3) p.p. Further, this averted an additional 3,979 (3,453‐4,298) deaths in France, 1,133 (‐312‐1,358) in Germany, and 1,331 (502‐1,794) in Italy; and prevented gross domestic product (GDP) losses of €6.0 (5.9‐6.1) billion in France, €1.4 (1.3‐1.5) billion in Germany, and €2.1 (2.0‐2.2) billion in Italy. Notably, the application of COVID certificates substantially reduced the pressure on intensive care units (ICUs) and, in France, averted surpassing the occupancy levels where prior lockdowns were instated. Varying government communication and restrictions associated with COVID certificates may explain country differences, for example, the smaller effect in Germany. Overall, our findings are more sizeable than predicted. This analysis may help to inform decisions about when and how to employ COVID certificates to increase vaccine uptake and thus avoid stringent interventions, such as closures, curfews, and lockdowns, with large social and economic consequences.