 [ Symptoms ] what causes bipolar disorder [ Disease ] people age 50 and older can now get merck is zostavax shingles vaccine the vaccine already was approved for people age 60 and older the approval is based on a merck clinical trial that showed the vaccine to be about 70 effective in preventing shingles in the younger age group the study also found that even when vaccinated 50 somethings did get shingles they suffered far less pain and far shorter bouts of the painful sometimes disabling disease