Sorry to hear that your child has developed a rash/fever after vaccinations. If you're concerned for your child's health always make sure to speak with your doctor or local health center, as internet diagnoses aren't nearly as reliable regarding your child's individual case and history.
Here's a quick FAQ taken from vaccineinformation.org regarding measles vaccines :
"If my child develops a rash after getting the MMR vaccine, is he contagious?
Transmission of the measles vaccine virus does not occur from a vaccinated person, including those who develop a rash. No special precautions (e.g., exclusion from school or work) need be taken." http://www.vaccineinformation.org/measles/qandavax.asp
Rash/fever is quite a common side effect to the MMR vaccine and happens in about 1 of 6 people but still, definitely contact your doctor or clinic to get a better diagnosis and treatment for your questions/concerns. Hope this helps!