Habermas categorises public scientific controversies into moral, ethical, scientific, intellectual and political. Elements of the Vaccine Controversy can fit into all of these categories however in the controversies I am describing it is more ethically based and occurs when individuals life choices are challenged by science based policy.
As an example few would argue that a parent has a moral duty to protect their child from harm. It is the different ethical choices that we make that creates the controversy. One parent will choose to vaccinate their child to protect their child from illness and for the benefit for the community. Another will chose not to vaccination for fear there may be an adverse reaction or because they chose to use alternate health care.
In a Habermas framework, a scientific claim or dispute is made publicly aware through publication, this may lead to new or shift in government policy/legal challenges. A public scientific controversy will then evolve if individuals ethical beliefs or life choices are challenged. Freedom of choice, health, safety, parental rights,or religious rights. It is then that these individuals with common ethical beliefs form advocacy groups to effect change.