Dr Isaac Golden of Australia conducted a 15 year clinical study and ongoing trials. The results of this study, including the safety and efficacy of HP, are published in Dr. Golden’s recent publication Homeoprophylaxis – A Fifteen Year Clinical Study. His findings included a 90% effectiveness rate for preventing pertussis in those children exposed. Additionally, he found that long term health outcomes were improved for those participating in the HP program. They had fewer ear infections, colds, sore throats and asthma. See his site here.