A free and open API for a variety of detailed information about COVID-19, influenza, and vaccines. The data's granularity can be adjusted and historic information is available.
This API provides a big range of detailed information about multiple viruses. From COVID-19 global data overviews to city/region specific mobility data, and data on Influenza outbreaks. The disease.sh Open Disease Data API also provide official government data for some countries, which you can compare to findings from Johns Hopkins University and other data providers. Datasets include COVID cases by city, county, state, country. Data providers feeding into the API include Worldometers, the New York Times, and Johns Hopkins University. The core team of the API currently consists of 4 people from 4 different countries working hard to keep this up and running, but it's an open-source project, so if you want to contribute, please follow this link: https://disease.sh.