Immunocontraception

Immunocontraception is a birth control method that uses the body's immune response to prevent pregnancy.

Contents

In humans

Experiments are undergoing to test the effectiveness of an immunocontraceptive vaccine that inhibits the fusing of spermatozoa to the zona pellucida. This vaccine is currently being tested in animals and hopefully will be an effective contraceptive for humans. Normally, spermatozoa fuse with the zona pellucida surrounding the mature oocyte; the resulting acrosome reaction breaks down the egg's tough coating so that the sperm can fertilize the oovum. The mechanism of the vaccine is injection with cloned ZP cDNA, therefore this vaccine is a DNA based vaccine. This results in the production of antibodies against the ZP, which stop the sperm from binding to the zona pellucida and ultimately from fertilizing the oovum.[1]

Another vaccine in investigation is one against HCG. This immunization would produce antibodies against hCG and TT. Antibodies against hCG would prevent the maintenance of the uterus for a viable pregnancy therefore preventing conception. Another vaccine that is utilized is the peptide ß hCG is more specific to hCG and a more rapid and effective response occurs in the absence of LH, FSH, and TSH.[1]

In animals

It is used to control populations of wild animals (e.g. white-tailed deer) [2] or feral animals (e.g. mustangs) and also muntjac deer to control their population. [3], because it is more humane than culling, and cheaper and less labor-intensive than spaying or castrating animals. It is not popular for domestic animals.

One drug often used for immunocontraception is porcine zona pellucida or PZP. It is made from the zona pellucida of pigs. It is similar enough to that of other animals that a female animal vaccinated with PZP will produce antibodies against her own oocytes, which prevent fertilization.

Among the other animals it has been used for are:

References

  1. ^ a b Markert U. Immunology of gametes and embryo implantation. Switzerland: Karger; 2005.
  2. ^ Remotely Delivered Immunocontraception in Captive White-Tailed Deer, by John W. Turner, Jr., Irwin K. M. Liu and Jay F. Kirkpatrick Journal of Wildlife Management, 56(1):154- (1992) jstor
  3. ^ Remotely-Delivered Immunocontraception in Feral Horses, by Jay F. Kirkpatrick, Irwin K. M. Liu and John W. Turner, Jr. Wildlife Society Bulletin 18:326-330 (1990) JStor
  4. ^ Nature 407:149, Sept 14, 2000 link
  5. ^ GnRH immunocontraception of male cats J.Levy, L.Miller, P.Cynda Crawford, J.Ritchey, M.Ross, K.Fagerstone Theriogenology, Volume 62, Issue 6, Pages 1116-1130 Elsevier

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