You can space out each vaccine if you want. Some places will give a separate vaccine for all three diseases. However, this is a foolish idea for multiple reasons. Firstly, it does not reduce the risk of a vaccine reaction. You’re actually increasing a child’s exposure to the minute amount of chemicals in each vaccine as you are giving three vaccines rather than one and therefore three times as many chemicals. Secondly, you are forcing your poor kid to get three needle sticks rather than one. Thirdly, you are also potentially increasing the need to get three doctor’s visits. As three shots are generally given in order to provide maximum protection, this actually means NINE shots rather than three.
So you can do it. But you really shouldn’t. You could, of course, aim to get measles, mumps and rubella but that would be even more foolish and far riskier.