Immunocontraception
Encyclopedia
Immunocontraception is a birth control
method that uses the body's immune response to prevent pregnancy
.
. 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.
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.
) or feral
animals (e.g. mustangs
) and also muntjac deer to control their population. , 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:
Birth control
Birth control is an umbrella term for several techniques and methods used to prevent fertilization or to interrupt pregnancy at various stages. Birth control techniques and methods include contraception , contragestion and abortion...
method that uses the body's immune response to prevent pregnancy
Pregnancy
Pregnancy refers to the fertilization and development of one or more offspring, known as a fetus or embryo, in a woman's uterus. In a pregnancy, there can be multiple gestations, as in the case of twins or triplets...
.
In humans
Experiments are undergoing to test the effectiveness of an immunocontraceptive vaccine that inhibits the fusing of spermatozoa to the zona pellucidaZona pellucida
The zona pellucida is a glycoprotein membrane surrounding the plasma membrane of an oocyte. It is a vital constitutive part of the latter, external but of essential importance to it...
. 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
Acrosome reaction
During fertilization, a sperm must first fuse with the plasma membrane and then penetrate the female egg in order to fertilize it. Fusing to the egg usually causes little problem, whereas penetrating through the egg's hard shell can present more of a problem to the sperm...
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.
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.
In animals
It is used to control populations of wild animals (e.g. white-tailed deerWhite-tailed Deer
The white-tailed deer , also known as the Virginia deer or simply as the whitetail, is a medium-sized deer native to the United States , Canada, Mexico, Central America, and South America as far south as Peru...
) or feral
Feral
A feral organism is one that has changed from being domesticated to being wild or untamed. In the case of plants it is a movement from cultivated to uncultivated or controlled to volunteer. The introduction of feral animals or plants to their non-native regions, like any introduced species, may...
animals (e.g. mustangs
Mustang (horse)
A Mustang is a free-roaming horse of the North American west that first descended from horses brought to the Americas by the Spanish. Mustangs are often referred to as wild horses, but there is intense debate over terminology...
) and also muntjac deer to control their population. , because it is more humane than culling
Culling
Culling is the process of removing animals from a group based on specific criteria. This is done either to reinforce certain desirable characteristics or to remove certain undesirable characteristics from the group...
, 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
Porcine zona pellucida
Porcine zona pellucida is a form of zona pellucida extracted from the ovaries of pigs, often referred to by the initials PZP.The zona pellucida is a thick membrane that surrounds the unfertilized eggs of mammals. In order for an egg to be fertilized, sperm must first bind to, and then penetrate the...
or PZP. It is made from the zona pellucida
Zona pellucida
The zona pellucida is a glycoprotein membrane surrounding the plasma membrane of an oocyte. It is a vital constitutive part of the latter, external but of essential importance to it...
of pigs
PIGS
PIGS is a four letter acronym that can stand for:* PIGS , Phosphatidylinositol glycan anchor biosynthesis, class S, a human gene* PIGS , the economies of Portugal, Italy , Greece and Spain...
. 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:
- ElephantElephantElephants are large land mammals in two extant genera of the family Elephantidae: Elephas and Loxodonta, with the third genus Mammuthus extinct...
s - CatCatThe cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s