For those unhappy with the social distancing measures as currently implemented by AC,
this short article from Aviation Week may be interesting. The conclusion is that the air filters and air flow in the cabin make it unlikely for COVID-19 to be transmitted during a flight.
A key quote:
[T]here have been some known cases of people boarding airliners for long flights and it later being discovered they were infected with COVID-19 before they boarded, but follow up tracing has seen no cases of transmission to other passengers.
(And these incidents were
before airlines started blocking middle seats, requiring face masks, etc)