The issue of whether we should force parents to immunise their children against (common) diseases is, in my opinion, a social rather than a medical question. Since we are free to choose what we expose our bodies to in the way of food, drink, or religion for that matter, why should the question of medical 'treatment' be any different?
Medical researchers and governments are (primarily) interested in overall statistics and trends and in money-saving schemes which fail to take into consideration the individual's concerns and rights. While (immunisation) against diseases such as tetanus and whooping cough may be effective, little information is released about the (harmful) effects of vaccinations which can sometimes result in stunted growth or even death.
The body is designed to resist disease and to create its own natural immunity through contact with that disease. So when children are given (artificial) immunity, we create a vulnerable society which is entirely dependent on immunisation. In the event that mass immunisation programmes were to (cease), the society as a whole would be more at risk than ever before.
In addition there is the issue of the rights of the individual. As members of a society, why should we be (obliged to) subject our children to this potentially harmful practice? Some people may also be against immunisation on religious grounds and their needs must also be considered.
For these reasons I feel strongly that immunisation programmes should not be obligatory and that the (individual) should have the right to choose whether or not to participate.