If it is protocol for them to clean surfaces after every longhaul flight then they absolutely do not. I always take a pack of Clorox wipes on board and the very first thing I do is clean my entire seat area. The dark brown / black colour of the wipe after use is evidence of how utterly grim and disgusting the club suites are. I always find evidence of crumbs and dust in the storage compartments too.

There's not a whole lot you can do if you're seated near someone who is coughing or looks visibly unwell; you can't stop breathing and most evidence on masks is that they stop YOU spreading germs but don't necessarily do a whole lot to protect you from OTHERS who are spreading germs. I do use Vicks First Defence nasal spray and repeat use a couple times during flight; I am a believer that it works. The only thing you really have any control over is what you TOUCH, so I am always mindful to never touch anything in the WC, including the door handle (use a tissue), or - if you do - immediately use hand wipes when back to your seat and ensure they are wipes that contain ingredients that kill VIRUSES (most only kill bacteria). Your mobile phone is another huge source of germs, so I always wipe mine down every few hours.

Call me a germaphobe but the above has kept me in generally good stead.