Suppressed symptoms with medication. Yes, just like people have done with the cold and flu for ages now. Cold and flu medications which even have advertised with the line "No one will know you're sick!"

A couple years ago, if you suggested that maybe you shouldn't bring Little Johnny to the old age home to visit Granny while he has the sniffles would be met with "You hate children! Eee!" or something ... never mind the couple of frail ones on oxygen that dropped dead a couple weeks after Sniffly Johnny's visit ....