Here's a link to what the NMSS has to say about vaccinations:

http://www.nationalmssociety.org/liv...ons/index.aspx

And here's a quote:

The information about the shingles vaccine -- Zostavax -- isn't as clear-cut as it is for some other vaccines. In general, MS specialist neurologists do not recommend any live-virus vaccine for people with MS because live-virus vaccines can precipitate an increase in disease activity. However, Zostavax is somewhat unique because most people have had chicken pox earlier in their lives and therefore already have the virus in their bodies. If a person has had chicken pox or tests positive for the antibodies, this would likely be a safe and beneficial vaccine to take. However, each person needs to discuss the potential benefits and risks of this vaccine with her or his healthcare provider. In terms of the possible risks for a person with MS whose close family member receives this or any other live virus vaccine, MS specialists are not in agreement. This is another decision the person with MS needs to discuss with her or his physician.