Engineered antibody that snags sperm could be an effective non-hormonal contraceptive

An engineered antibody could be a potent non-hormonal contraceptive for women, ensnaring sperm and inactivating them before they can fertilise the egg.

The antibody was developed from a natural one discovered in an immune-infertile woman by a Japanese group in the 1980s. The engineered antibody was produced in tobacco plants and has six fragment-antigen binding (Fab) arms with an affinity for a glycoprotein found almost exclusively on sperm.¹