My little boy is booked in for his pre school booster vaccine this week, kind of just got the letter last month and booked without much thought, then I have gone to look at side effects on the nhs website today, and it says reactions to the mmr can be 1-4 weeks later… is this the case for the majority or not? I really can’t remember his reaction to the first lot as I have had another baby since! We go on holiday in less than 4 weeks, should I reschedule or not? He will be 3 years 5 months next week