Sperm-based contraceptive vaccines: current status, merits and development.

At the present growth rate, the world population is estimated to reach a phenomenal 8.9 billion people by the year 2050, posing a great risk of overpopulation. Therefore, new strategies of contraception are required. A novel contraceptive strategy that is receiving considerable attention is that of immunocontraception. Spermatozoa have proteins that are unique, cell specific, immunogenic and accessible to antibodies. The targeting of antibodies to gamete-specific antigens implicated in sperm function, sperm-egg binding and fertilisation could block sperm binding and thus fertilisation. The present review highlights the current status, relative merits and future directions for various sperm-based candidate antigens with regard to the development of a contraceptive vaccine.