Horse blood has been a source of tetanus serum, and gamma globulin to fight disease has long been derived from the blood in human placentas (the afterbirth).
No zirga asinīm ir ticis izgatavots serums pret stingumkrampjiem, savukārt gammaglobulīns, ko lieto cīņā pret slimībām, ilgu laiku tika iegūts no asinīm, kuras satur cilvēka placenta.