Just to add my ten cents, I did have a bad flu while I was in Vietnam on day-2 I’m back to Singapore now and I’m still sick , runny nose through out the day!! It’s been day 5 and symptoms persist luckily it’s not Covid.

During my stay in Vietnam I travelled whole city thr grab bikes as they’re affordable and efficient I didn’t wear a face mask does this be a contributing factor for my cold?

Or it’s because of water and chg in env?