How long must one wait after being vaccinated with shingles vaccine before coming in contact with children who have not had chicken pox or chicken pox vaccine?

From CBS2Chicago.com:

Shingles Vaccine Caution Urged Around Infants Maker Says Patients With Live Vaccine Should Be Careful Around Infants, Immunocompromised

The Chicago CBS newstory featured a grandmother who stayed away from her newborn grandchild for 8 weeks because: "They called Reina's pediatrician, a major medical center, a children's hospital, the CDC, and the vaccine-maker, Merck. No one could say for sure."

From StreeetInsider.com:

Tell your health care provider if you expect to be in close contact (including household contact) with newborn infants, someone who may be pregnant and has not had chickenpox or been vaccinated against chickenpox, or someone who has problems with their immune system. Your health care provider can tell you what situations you may need to avoid.

Evidently this is an open question. I'm not sure where the recommendation for 8 weeks came from in this case. Somewhere else I came across three months; but the sources are not clear-cut.