Adverse Events following 12 and 18 Month Vaccinations: a Population-Based, Self-Controlled Case Series Analysis

Live vaccines have distinct safety profiles, potentially causing systemic reactions one to 2 weeks after administration…. There are significantly elevated risks of primarily emergency room visits approximately one to two weeks following 12 and 18 month vaccination. Future studies should examine whether these events could be predicted or prevented.

Abstract. PloS one 2011; 6(12):e27897