Funding for this research was provided by:
National Natural Science Foundation of China (81602935)
Sichuan Science and Technology Program (2020YFS0015, 2020YFS0091, 2020YFS0015, 2020YFS0007, 2020YFS0001, 2020YFS0559)
Health Commision of Sichuan Province (20PJ092)
Humanities and Social Sciences Program of Sichuan University (2018hhf-26)
Received: 10 August 2020
Accepted: 5 January 2021
First Online: 10 February 2021
Ethics approval and consent to participate
: The ILI surveillance was a routine surveillance activity. The analysis of ILI data was not considered as human subject research. No administrative permission was needed to assess the data.
: Not applicable.
: The authors declare that they have no competing interests.