flu shots public schools - Google Search
Perhaps because such efforts could work towards keeping children in school, rather than being relegated to the role of a parental figure in their prime learning and developmental years. Also less pregnancies reduce the burden and costs imposed on the health care system, much like the rationale for distributing the aforementioned flu shots free of charge.
Scientifically correct, sure, but pragmatism should enter the picture as well. Most of us recognize that kids who have willing sexual partners will have sex if possible and often so. Expecting otherwise and teaching accordingly is a recipe for disaster, evidenced by the abysmal failure abstinence only education has rendered thus far.