First of all, recenter the project goal
This should not be considered a COVID-19 response app, but a pandemic response app. The next time a pandemic occurs, the app should be quite capable of handling the info for that pandemic, no need to reinvent the wheel.
Of course, the timeframe for a response app to be actually useful for this round is limited, so consider that whatever you can cobble together is basically a trial run. Limit the functionalities to the bare minimum. Right now there is a perfectly functional website. People can go there, so it's not like we have no information to go on.
By all means, make an app if there's any chance that it can help get the right information out to people, but take the long view. COVID-19 is not the first pandemic to hit us, and it certainly won't be the last.