Travellers on the tourist route rarely need injections.
I've been here 16 years and only take precautions against dengue as I reside in the Central Highlands.
You can catch Malaria and Dengue within HCMC (they are presently fumigating streets nightly at this time).
However, be prepared. Forget your DEET and buy SOFRELLA in VN - a nice smelling repellent made in Japan. Bring a roll of Duct tape to seal up mosquito nets (usually supplied in hotels in affected areas - in the long box at the head of beds).
Keep your feet and socks clean and wear long sleeved shirts / long pants at dawn and dusk - the favourite hunting time for the M an D carrying mosquitoes.
But as I said you have few worries when doing the Ha Noi >> HCMC route and Sa Pa is in a temperate zone (think mid-Europe).
#3 CatBa2 has been a member since 6/11/2007. Posts: 53
Thankyou for replies and info CatBa2....very handy and much appreciated :-)
#4 hippydiza has been a member since 22/6/2008. Posts: 2