No data or evidence was presented supporting this, and no valid immunological theory put forward. With the MMR, children are given full protection with just two doses. With single vaccines, children would need six separate injections. This is less safe than with MMR, where most children are given good protection by a single dose and protection is virtually complete by dose two. Delaying immunisations by splitting them in this way therefore has a similar effect to reducing the proportion of children immunised.
More children are unprotected, increasing the risk to themselves and to other children.
Giving MMR separately as six injections instead of two would increase the discomfort for children three fold, since each injection can be uncomfortable and the act of immunisation is sometimes distressing for children. All the evidence suggests that uptake is in fact poorer with single vaccines than with the MMR, and so with single vaccines fewer children would be protected. With six injections it is very likely that many children would not complete the course and therefore, to suggest that giving six injections rather than two will improve uptake is incorrect. Some people argue that making single vaccines available would improve uptake because parents who refuse the MMR would take the single vaccines. In fact, the evidence from the UK and elsewhere is that the opposite is true.