I know with all the controversy surrounding vaccinations in small children, that it seems a bit odd to propose a new vaccine, but here I go anyway.
I propose a Whining Vaccine. Children would receive this vaccine on or immediately following their one year birthday. While it is given in shot form, it works almost immediately, so that any tears or protests are eliminated on the spot.
There is a 99% success rate in studies so far and the side effects are minimal and not that bad anyway. They include excessive smiling, uncontrollable bursts of laughter, involuntary hugging, and a general attitude of agreement.
I allowed my middle child, age 21 months, to be a test subject for this vaccine. Here are the before and after photos:
Check your local pediatrician's office for availability. :)