Despite vaccination, China needs non-pharmaceutical interventions to prevent widespread outbreaks of COVID-19 in 2021
Juan Yang, Valentina Marziano, Xiaowei Deng, Giorgio Guzzetta, Juanjuan Zhang, Filippo Trentini, Jun Cai, Piero Poletti, Wen Zheng, Wei Wang, Qianhui Wu, Zeyao Zhao, Kaige Dong, Guangjie Zhong, Cécile Viboud, Stefano Merler, Marco Ajelli, Hongjie Yu
Abstract
Abstract COVID-19 vaccination is being conducted in over 200 countries and regions to control SARS-CoV-2 transmission and return to a pre-pandemic lifestyle. However, understanding when non-pharmaceutical interventions (NPIs) can be lifted as immunity builds up remains a key question for policy makers. To address this, we built a data-driven model of SARS-CoV-2 transmission for China. We estimated that, to prevent the escalation of local outbreaks to widespread epidemics, stringent NPIs need to remain in place at least one year after the start of vaccination. Should NPIs alone be capable of keeping the reproduction number ( R t ) around 1.3, the synergetic effect of NPIs and vaccination could reduce the COVID-19 burden by up to 99% and bring R t below the epidemic threshold in about 9 months. Maintaining strict NPIs throughout 2021 is of paramount importance to reduce COVID-19 burden while vaccines are distributed to the population, especially in large populations with little natural immunity.