What is the very thing a Brazilian sports father fear the most? Seeing a son support the rival team. With that insight, Bandsports created the Anti-Rival Vaccine: an idea that used rivalry to support the children immunization campaign against H1N1. During an outbreak of the virus in São Paulo, we set up a special clinic for football enthusiasts. In there, consultation rooms were fully decorated with the colors of the four major São Paulo soccer teams. Doctors and nurses had jersey-like uniforms and even the syringes were customized. Fathers just had to choose a rival team and their sons H1N1 immunization took place at that team's room. The vaccines were the regular approved ones, only the environment changed. All to make children associate the pain of that experience with the rival, protecting them from the disease and from the wrong team. With Bandsports Anti-Rival Vaccine, sports fathers had two reasons to rest easy: no H1N1 and none of that rival nonsense.