Slight over reaction. Any company I’ve worked for you’ll simply be instructed to tape off the effected area with ticket roll, open all possible windows for ventilation and then continue until realistically possible where the bus can either be swapped or cleaned on the spot.
A simple mop and bucket and a few wet wipes usually suffices also… no bus company I know will be sending guys in hazard suits for sick! Yes, it has a tendency to go everywhere, but it’s just one of those things.
That’s what happened on a bus I was on once at Conisbrough on X78. A passenger was sick upstairs, it was reported to the driver & all the upstairs windows were opened. The passengers all moved downstairs & the bus ran to Rotherham before terminating & returning to depot. The passengers all transferred to the next bus