Наверное аллергия, слишком быстро для вирусов.Yes. Most children will have no side effects. MMR vaccine can cause a rash or fever in some children five to 12 days after the needle is given. This may last for a few days. Occasionally, a high fever can cause a convulsion. The convulsion comes from the high fever caused by the vaccine rather than the vaccine itself. This does not make the child any more likely to get epilepsy, brain damage or any other nerve problems. Convulsions caused by high fever are more likely to occur in children who have had convulsions before or whose parents, brothers or sisters have had convulsions.The mumps part of the vaccine may cause fever and swelling of the glands in the neck. Meningitis (an infection of the fluid and lining covering the spinal cord) may occur very rarely, in one in 800,000 people who get the vaccine. The meningitis caused by mumps vaccine is mild, and permanent brain damage does not occur.The rubella part of the vaccine may cause a mild fever, rash or swelling of the glands in the neck in one out of seven children. This usually happens 6 to 10 days after getting the shot and lasts for one to 2 days. Less than one in 200 children may develop swelling and pain in some joints after the vaccine. Up to one in four teenage girls and adult women may get painful swelling of some joints within one to three weeks after vaccination. The joint pain and swelling usually lasts only a few days. Very rarely, chronic arthritis may occur.Mild, temporary blood clotting problems have been reported during the month following immunization with MMR vaccine. This condition occurs rarely and does not result in long-term problems.