https://techcrunch.com/2020/03/18/twitter-coronavirus-covid-19-misinformation-policy/

You don’t have to go far to find someone online downplaying the severity of a global pandemic that’s shut down entire economies and ground everyday life to a halt. Knowing that, Twitter will take extra steps to remove tweets that put people at risk of contracting the novel coronavirus as it rapidly sweeps through communities around the globe.

On Wednesday, Twitter updated its safety policy to prohibit tweets that “could place people at a higher risk of transmitting COVID-19.” The new policy bans tweets denying expert guidance on the virus, encouraging “fake or ineffective treatments, preventions and diagnostic techniques” as well as tweets that mislead users by pretending to be from health authorities or experts.