MMR vaccine – The most common side effects of vaccination in children are fever and rash. If these problems occur, it is usually within 7 – 12 days after. No adverse effects were observed, except for moderate pain during the injection, and there has been no recurrence after more than a year of follow-up. and vaccines may lead to serious adverse effects in some instances. (MMR) vaccine and autism, an assessment of the broader significance for soci-PDF | Hemos leído con mucha atención el interesante artículo de la Dra. Silvia Guiral et al.1 «Reemergencia del sarampión. Situación epidémica en la. What are the possible side effects of M-M-R II? The most common side effect of vaccination with M-M-R II is pain at the site of the shot for a short time. Other The side effects that do occur are usually very mild, such as a fever, rash, soreness or swelling where the shot was given, or.