Single vaccine alternative to MMR. Hands mixing vaccine with diluting agent. This is the preparation of one of a series of single vaccinations intended to replace the combined MMR (measles, mumps and rubella) vaccine. There is concern amongst the public in some countries about a possible link between MMR and autism. The diagnosis of autism is rising in developed countries. However, epidemiological studies suggest that the beginning of this increase did not coincide with the introduction of MMR. Vaccines contain weakened or partial forms of viruses. They prepare the immune system to mount a quick response when exposed to the live virus.