Unless you plan to visit the deep Amazon, typhoid, yellow fever, and malaria are not diseases you’ll need to worry about. The only reason you might consider a yellow fever vaccination is if you will be traveling directly FROM Ecuador to Costa Rica, Panama, or Bolivia. Those countries do require proof of yellow fever vaccination for travelers coming from certain countries including Ecuador (however, Panama and Bolivia have never asked to see my proof of vaccination).
I would suggest that you strongly consider getting your Hepatitis A vaccination. I believe it’s a series of shots, so you’ll want to start soon so you’re finished before you come to Ecuador. I had Hepatitis A several years ago and while the disease itself is not life threatening and does not do lasting damage, I would rather have had a vaccination than the illness. It exhausts you for about 6 weeks and the first few days feel like having a severe case of the flu.
Having said that, many expats here have never received the vaccination and have never contracted Hep A. But I’m proof that it is possible to get it here and I’d urge erring on the side of caution.