When I got my first overseas assignments in 1976, I was required to get a huge battery of inoculations including typhus, typhoid, yellow fever, smallpox, and several others I’ve forgotten. I was in some really remote jungle locations in Asia and South America and fortunately didn’t get sick...until I got Hep A in Durango, Mexico at the very end of my overseas stint. At that time, there was no Hep A vaccine.
You probably got the vaccine for scrub typhus. It can be a thing in SE Asia, especially out in the bush. It’s spread by chiggers, of all things.
I gather Yon means epidemic typhus, which used to be thing during wars and famines. Now it’s rare. It’s spread by body lice in overcrowded conditions. Napoleon’s troops were decimated by it in 1812 (his ill-fated Russian campaign), and it killed many thousands on the Eastern Front in WWI.