Shanghai eased COVID curbs and fully reopened on Dec 5, 2022. The number of COVID-19 patients continues to rise and more people will be infected in the future.
Without official data, someone predicted the first wave of infection will end on Jan 26, 2023, such as the user named chenqin in the Zhihu platform. He used the model which adopts the main data source from the search engine to get the prediction.
And some think the subway ridership infers the Shanghai COVID-19 infections, people will stay at home when they are infected.
Record the Shanghai subway ridership and Baidu Search Index about COVID to observe.

So far, there are two insights from the following data viz:

• Baidu Index and subway ridership are a negative correlation. Between Dec 12 and Dec 30, they were apparent in the chart. Less subway ridership, higher search volume. It seems more patients search for COVID information at home.
• The subway ridership is less than the data in 2021 and 2020 from Dec 12. There are stable trend patterns in 2021 and 2020. But in 2022, it seems the first wave of people got sick after reopening and dropped quickly.

update: 2023/1/11

Adding information from the 2022-2023 Spring Travel Season: a lot of people will be leaving Shanghai to their homes during the 40 days preceding the Spring Festival.

Tool: tableau public