Andy Crisconi of One World Trekking recommends:
I receive immunization questions all the time from clients. Personally, I believe in getting the minimum recommended or required by the country being visited. Most people hate shots and they are/have become a rather expensive part of trip preparations. Most of my treks are in the Himalayan countries of South Asia.
Minimum vaccinations I recommend to my clients traveling are:
Doctors and travel clinics tend to err towards more shots to cover all possible situations, so I think it important that each individual traveler and the tour operator do the research and discuss the options. Also, many times different shot or pills are recommended depending on the time of year you visit a certain country. For folks wanting to visit Nepal during the monsoon months, I may recommend they also get a Meningitis shot (For more info on travel & meningitis, read this).
In places like Nepal, you can be often days from medical assistance so it pays to be prepared and stay healthy.
In terms of general travel safety in Asia, a few tips I would also offer are:
1. Water safety: Assume all water to be contaminated. Drink and brush your teeth with bottled or treated water only. Keep your mouth closed while taking a shower. (Not sure whether to use bottled water or treated water, check out this great article to water safety while traveling.)
2. Be a compulsive hand washer.
A bottle of hand sanitizer should be carried with you during the trek and be used after visiting the restroom, before each meal, after handling paper bills and coins, before putting-in or taking-out contact lenses etc. Hepatitis A and Typhoid are passed in human faeces, so be a compulsive hand cleaner.
The typhoid vaccine is strongly recommended for Asia and is available in both pill and shot form.
1. Get a rabies vaccination before you travel.
Did you know that rabies is 99.9999% fatal once contracted? And in some Asian countries, there are localised shortages of the rabies vaccine.
Trekkers in developing nations are in an area where the is a much higher incidence of rabies than most industrial nations. Additionally, most people do not expect to be bitten by a dog or animal; this is what makes it an accident. 95% of rabies deaths occur in Asia and Africa where most locals struggle to afford personal vaccinations and vaccinations for their dogs. However, rabies has been eliminated from many countries in South America due to efficient vaccination programs.
If you're bitten, your expensive trip is basically over, right there. That person needs to evacuate to a large city with proper medical care, although The post-exposure prophylaxis is generally indicated and may be difficult to find. Most rural and developing nation hospitals may not use the safer rabies vaccines instead using older types with risk to the traveler, such as severe allergic reaction.
Pre-exposure shots would have helped prevent this, although they are also hard to come by currently.
I try to discuss pros and cons with people but am a big fan of this vaccine, just because of the seriousness of the illness. I would DEMAND my mother or wife got this vaccine prior to trekking in a remote area and consequently offer the same advice to my patients. At the end of the day, the choice belongs to the patient/traveler.
2. Avoid mozzie bites
Use DEET and permethrin, long sleeves and pants and bed nets to prevent insect bites. Need more tips? Check out this article on minimising mosquito bites.
3. Consider getting a Japanese Encephalitis vaccine
JE is spread through the bites of infected mosquitoes making it very difficult to prevent - and treatment once acquired, is only supportive. This means that once you actually get the illness, there is not a lot that can be done about it. However, a new (and safer) vaccine against JE has been developed and is worth considering if you are travelling in SE Asia. Find out more about JE here.