Title: The association between the intensity and duration of non-pharmacological interventions and covid-19 infection and excess mortality

Abstract

Background: We evaluated the association of intensity and duration of non-pharmacological interventions (NPIs) and implementation of vaccination strategies with COVID-19 infection and excess mortality (EM) in Europe. Methods: Data comes from Our Word in Data, we include 22 European countries from January 20, 2020, to May 30, 2021. The time-varying constrained distribution lag model was used in each country to estimate the impact of different intensities and duration of NPIs on COVID-19 control, also considering vaccination coverage. We defined the main effect as the independent impact of daily intensive interventions. The added effect was defined as the added risk due to the duration of NPIs. Country-specific effects were pooled through multivariate meta-analytic. Results: This study found that high-intensity and long-duration of NPIs showed a positive main effect on reducing infection in the absence of vaccines, especially in the intensity above the 80th percentile and lasted 7days (RR=0.93, 95% CI:0.89-0.98). However, it was also associated with an increase in excess mortality and the average main effect showed an increasing trend with the duration and intensity. Specifically, it was associated with an increase of 44.16% (RR=1.44; 95% CI: 1.27-1.64) in the excess mortality under the strict intervention (the intensity above the 80th percentile and lasted for 21days). After the vaccination rollouts, the inhibition of the strict intervention on cases growth rate was increased (RR dropped from 0.95 to 0.87). Simultaneously, vaccination also alleviated the negative impact of the strict intervention on excess mortality (RR decreased from 1.44 before vaccination rollouts to 1.25 after vaccination rollouts). Besides, maintaining the strict intervention after the vaccination rollouts appeared to more reduce the cases, as well as avoids more overall burden of deaths compared with weak intervention. Conclusions: Our study highlights the importance of continued high-intensity NPIs in low vaccine coverage. Lifting of NPIs in insufficient vaccination coverage may cause increased infections and death burden. Policymakers should coordinate the intensity and duration of NPIs and allocate medical resources reasonably with widespread vaccination.