Twelve months from this week I will be off for two weeks in Tanzania. What vaccinations will I need for the trip?

You should think about:

Yellow Fever
Typhoid
Hep A & B (if you think you'll be in contact with other people's bodily fluids)
Malaria prophylactics

Many counties have health departments with someone therein designated to keep up with medical travel vaccination requirements.

Although my county is quite small, many folks travel overseas due to our hosting the Federal Law Enforcement Center and MAP International. The duty nurse even has the vaccines available at a cost on a sliding scale related to your income. She'll even get the staff physician to prescribe malaris prophylactics for you use (you pick them up and pay for them at the local drug store.)

You may want to check with you local health department?

I'm going in 3 weeks and went to our local health dept. Got yellow fever, typhoid, hep a and b and updated tetnus booster.

Had my Dr write a script for malaria meds and other 'just in case meds' doxcy, cipro,etc

Below is a link to the Center for Disease Control and the recommendations for East Africa.
I hope this helps.
http://www.cdc.gov/travel/eafrica.htm#vaccinesFarren Global Adventures.