Non-specific Effects of a Modified Measles Vaccination Schedule to Prevent Allergy and Unrelated Infection in Children

Inclusion Criteria: 1. Informed Consent as documented by signature 2. 6-month-old children 3. In overall good health, without any clinically significant concomitant disease states (e.g., renal failure, hepatic dysfunction, cardiovascular disease, etc.) and no clinically significant abnormal finding on history and/or physical examination 4. Fully immunised for age according to the Swiss vaccination schedule 1. with at least 2 doses of DTP-containing vaccine 2. the last dose of vaccine received at least 2 weeks prior to enrolment Exclusion Criteria: 1. Contra-indications to MMR, including 1. immunosuppression (i.e. proven, suspected, or planned) 2. allergy to a component of the vaccine 3. receipt of a live-attenuated vaccine in the four weeks prior to inclusion 2. Vaccine refusal 3. Indication for an early MMR vaccination, including 1. Measles outbreak 2. Planned immunosuppression (indication to an accelerated schedule to be completed before starting an immunosuppressive treatment) 3. Travel to a region with a high risk of measles outbreak 4. Indication for vaccination with MMR-varicella (MMRV) instead of MMR, including 1. severe eczema 2. parental will 5. Parental inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, known/suspected non-compliance, substance abuse, etc. 6. Plan to move out of the country or have prolong absence during the trial 7. Other sibling included in the trial (in the case of multiple pregnancy, only one child can be randomised) 8. Any temporary contra-indication to MMR, including child being sick (active significant illness, inclusion can be delayed a few days until the illness resolves)