More like your wife picked up pathogens on her flight back. Seems to me it's common for people to get sick after a flight. I am beginning to agree there are no 'viruses' as we have been led to believe. i do believe in shedding though or transmission. So whatever the pathogen is I think it can be passed onto people. The healthier you are, the less likely to get sick if you come into contact with a carrier, but if they are carrying a large enough load of the right stuff, it can be very nasty. People who say covid was a nothingburger have only part of the story. Yes many had flu which was re-diagnosed as covid, but there is also more than that. I think it changes depending on what they put in it in the labs and I think it is probably in the annual vaccines (maybe why so many were ill Winter 2019?) as well as the covid shots and maybe other methods have been used too to attack wider areas of people?