The goal for fertility control of animal populations is the development of a safe, economical and effective contraceptive. One offshoot of the development of this technology is the acquisition of multiple therapeutic strategies for diseases, such as immunotherapy probes for cancer. In the long run, successful population control requires multifactorial strategies. One component of population control is immunocontraception. Development of effective antigens for immunocontraceptive vaccines has been remarkable and has greatly advanced our understanding of the molecular mechanisms of fertilization. The chasm between the discovery of an antigen in the laboratory, to the implementation of an effective field program, is immense. The zona pellucida (ZP) immunocontraceptive that has been most extensively evaluated as a fertility vaccine antigen and the porcine ZP has received particular attention. The long-term goal of population control would be the use of a synthetic vaccine, e.g. the ZP, tailored to a target species. In the future, if populations’ levels are to be controlled by fertility vaccines, we should consider that the vaccinated animals could receive other health protective agents at the same time. For example, if a species were immunocontracepted, then they could be simultaneously vaccinated against habitat diseases such as rabies (Plumb et al., Rev Sci Tech, 26, 2007, 229).