Google posted a new Google Ads policy yesterday that does not allow ads for with "content that potentially capitalizes on or lacks reasonable sensitivity towards a natural disaster, conflict, death, public health emergency, or other tragic event."
In short, you cannot profit off of events like the COVID-19 outbreak. Google added "Examples (non-exhaustive): Appearing to profit from a tragic event with no discernible benefit to users; price gouging or artificially inflating prices that prohibits/limits access to vital supplies; sale of products or services (such as personal protective equipment) which may be insufficient for the demand during a sensitive event; using keywords related to a sensitive event to attempt to gain additional traffic."
Ginny Marvin from Search Engine Land said on Twitter that this "basically makes official that coronavirus-related keywords are off limits."
How Google will enforce this, is to be seen, but it is effective immediately.
Forum discussion at Twitter.