Measles, mumps, and rubella vaccine at age 6 months and hospitalisation for infection before age 12 months: randomised controlled trial.

Objective: To test for potential non-specific effects of an additional, early measles, mumps, and rubella (MMR) vaccine at age 5-7 months on risk of infection related hospitalisation before age 12 months.

Design: Randomised, double blinded, placebo controlled trial.

Setting: Denmark, a high income setting with low exposure to MMR.