Two case studies of modified measles in vaccinated physicians exposed to primary measles cases: high risk of infection but low risk of transmission. http://www.ncbi.nlm.nih.gov/pubmed/21...
Measles antibody: comparison of long-term vaccination titres, early vaccination titres and naturally acquired immunity to and booster effects on the measles virus. http://www.ncbi.nlm.nih.gov/pubmed/81...