World Bank Data Blog:

• “This blog presents a global dashboard that compiles publicly available Google search data and can be used by policymakers and the general public to understand how internet search interest for different terms or phrases can be used to effectively assess the spread of the coronavirus in real-time for almost 200 countries worldwide.
• Search interest for various symptoms of coronavirus is highly correlated with administrative COVID-19 cases and deaths as reported by the WHO, especially in countries with relatively well-developed reporting capacity. The correlations have been stable over time for the majority of countries, suggesting that even several months into the pandemic, when people fall sick, their information needs remain high.
• Search interest precedes official data by more than a week, on average, predicting spikes in the incidence of the disease. Observed instances with high search interest but low reported administrative cases are suggestive that the dashboard can warn of potential underreporting.”