COVID-19 World Symptom Survey is a partnership between Facebook and academic institutions. The survey is available in 56 languages. A representative sample of Facebook users is invited on a daily basis to report on symptoms, social distancing behavior, mental health issues, and financial constraints. Facebook provides weights to reduce nonresponse and coverage bias. Country and region-level statistics are published daily via public API and dashboards, and microdata are available for researchers via data use agreements. Over half a million responses are collected daily.
Detailed Methodology:Weights and Methodology Brief for the COVID-19 Symptom Survey
Symptom Survey Instruments:Version 1
Version 3 & 4
Country Regional Codes:Country Region Numeric Codes