It's long been proved that it's very low risk catching a cold/covid from touching objects. This came from studies late 2020 taking swabs around the London Underground (https://www.independent.co.uk/travel...-b2010015.html) that covid spores were so low from touch that you'd have to touch something almost immediately put your finger to your eye to have chance of catching covid from an area touched by someone with covid.

A virus is nearly always caught from people sneezing and coughing in your vicinity and you breathing in the same air. Obviously in a closed container such as a plane, it's far more likely to catch a cold or something like covid than out in the open air.

If you're that worried about catching something flying, simply don't fly. There's not much BA can do if people choose to fly and sit near you coughing and sneezing through the flight. Cleaning procedures to avoid covid was something we worried about in April 2020. The theory of 'enhanced cleaning to prevent against covid' was quietly forgotten about during 2020 for the above reason.