Http://www.cdc.gov/ The MMR and varicella vaccines may interfere with the tst results if the vaccines are administered before the skin test. If MMR or varicella vaccines are administered before the tst, a minimum of 4 weeks must separate the vaccine from the tst. Mmr and varicella vaccines can be administered at the same time, on the same day, or after the tst has been evaluated without interfering with the tst resul.
Some interfere. Tuberculosis skin tests (tst) evaluate whether a person has been infected with tb. Certain live vaccines can interfere with the test. Live virus vaccines such as mmr, varicella (chickenpox, shingles), & small pox may interfere with the test. If you need both test and vaccine, get the tst the same day as your vaccines or wait 4-6 weeks. Bcg also interferes, but a new blood test helps sort this out.