Hi sorry for not responding until now but had a rather distracting day...
@amireallythatsad: I must apologise; especially if it caused you a sleepless night. It was rather an insensitive post that I made and should not have implied criticism of everyone. To be honest it was really the content of the post from fishnet that tipped the balance, with the stuff about some 'expert' stating that fever causes autism, that there is little risk to children from mumps, and implying that even tetanus vaccination should be avoided. This is quite dangerous misinformation that I felt needed challenging; but my mistake was to imply everyone's views were also nonsense, and I certainly didn't mean it to be like that. I hope you, and the others mistakenly included, could accept my apology.
I do appreciate that allergies to things like egg and other proteins are of genuine concern to parents, and in my job as a clinical virologist we deal with these type of questions quite a bit. Sometimes we have to make assessments of whether to vaccinate children with much more serious conditions, such as epilepsy and severe neurological disease, but yet don't have the defined contraindications for MMR. What helps make the decision to advise first or second vaccinations is knowing that the effects of the wild-type diseases on these children would be so much more severe and probably life-threatening to someone with a genuine immunodeficiency.
By and large we go by the information and recommendations in the 'Green Book'; not just with a blind following as if it's some kind of Old Testament or written in stone, but because it is built on a huge amount of peer-reviewed science and clinical observation. The 2006 version is freely available in individual chapter form from the Dept of Health website:
www.dh.gov.uk/en/Publichealth/Healthprotection/Immunisation/Greenbook/DH_4097254
If you download chapter 23 on mumps, the risks associated with complications are summarised there in the first couple of pages (meningitis 15% i.e 1 in 6 children), orchitis 25% (1 in 4), and deafness between 1 in 3400 or 20,000 depending which study you take. The odds of developing deafness would be considerably higher in a child who had meningitis. My own personal experience is that two doctors I have worked with in the last ten years became deaf on one side after having mumps as children.
Once again, sorry to you for the uneccessarily harsh post and I'm more than happy to try and explain things if it will help.