My recent days (and nights) have been somewhat consumed with
writing as a guest author for an upcoming reproductive health textbook. Unbeknownst to me, my doctoral studies in
immunology and my scholarly writing would soon collide – all in the name of immunocontraception.
While researching emerging trends in human contraception, I stumbled across several
interesting articles mentioning that there has been some investigations into
vaccines to prevent pregnancy. It seems that there is already quite a
substantial science around vaccines for contraception in population control of
some wild animals. In fact, the wild horse population is already being managed
with dart-gun delivered anti-fertility vaccines.
I should mention that I have made my career providing
reproductive healthcare to women, not wildlife, so this talk about animal birth
control caught me a bit off guard.
Curious about how such a vaccine might work, I investigated a bit
further.
While it appears that the reality of the human contraceptive
is quite far away from debuting in the U.S. drug market anytime soon, there are
some interesting points to consider regarding this potential approach.
In a recent popular media article, the basic details of how
immunocontraception might work are revealed. (http://malecontraceptives.org/methods/immuno.php)
Based on the principles of antigen-antibody interaction (B-cell immunity),
vaccine developers are investigating cases of infertility and the phenomenon of
anti-sperm antibodies in women. Could it be possible to introduce an antigen
component that would sensitize the female immune system to sperm, so that an
immunologic response could be mounted when sperm are actually encountered? After
all, a small percentage of infertility cases are related to naturally occurring
anti-sperm antibodies in women, anyway! How can this reaction be harbored and
cultivated to be of use in contracepting women?
Of course the first thought that comes to mind is, how would
immunologic “memory” be reversed in the future, if the woman decides to pursue
a pregnancy? It is the reversibility and long-term consequences that have
researchers scratching their heads in search of a solution to this dilemma.
There are also vaccine targets in men, specifically cells in
the testis and epididymis. These mechanisms however, are even less developed
than the work around anti-sperm antibodies, still considered under development
in the very early stages of basic science knowledge development.
So for now at least, ladies should hang onto their pills, rings,
patches, and implants. But keep an eye out for upcoming developments and don’t
forget to ask your healthcare provider for the anti-sperm vaccine when it
becomes available.
And for the guys…your desires to play the field without
actually sewing wild oats may just be on the horizon…but still many years away!
References
- O’Rand, MG, and IA Lea (1997) "Designing an effective immunocontraceptive." Journal of Reproductive Immunology 36: 51-59.
- Aitken, RJ (2002) "Immunocontraceptive vaccines for human use." Journal of Reproductive Immunology 57: 273-287.
- Schrater, AF (1995) "Immunization to regulate fertility: Biological and cultural frameworks." Social Science and Medicine 41(5): 657-671.
- O’Rand, MG, EE Widgren, P Sivashanmugam, RT Richardson, SH Hall, FS French, CA VandeVoort, SG Ramachandra, V Ramesh and A Jagannadha Rao (2004) "Reversible immunocontraception in male monkeys immunized with eppin." Science 306(5699): 1189-1190
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ReplyDeleteThis is a really interesting concept, and I think it is indicative of where the contraceptive field is going. I was not familiar with an immune approach to contraceptives, but I have heard of research pushing sperm specific targets for effective contraceptive methods. For example, work out of Dr. Hermann Steller's lab at Rockefeller University is looking at the role of sperm specific proteosomes that play an important role in spermatogenesis. Also there are sperm specific septins that are also vital for proper sperm function. And there is a sperm specific calcium channel that is necessary for sperm capacitation. All of these targets, being sperm specific, could have very limited side effects for the male and female if specific, non-permanent inhibitors are developed.
ReplyDeleteI also think this is an interesting topic. However, if this drug will lead to an 'immunological response' in the presence of sperm, then what type of response does that entail? Did the article mention anything about how the body will react to physically block out the sperm and how that can affect the female's body? Can this lead to inflammation?
ReplyDeleteI haven’t heard of this before. I would also think this would be irreversible and I would be a little concerned with the response mounted by the immune system to sperm and the amount of possible chronic inflammation. With chronic inflammation I would think the chances of developing cancer would increase with longtime use of this contraceptive. I wonder if the vaccine was permanent in the horses?
ReplyDeleteThis is a very interesting topic. I guess this is something that could potentially work in humans at a time in a persons life when they are done having kids since this seems to be a irreversible system. So maybe an alternative to a more permanent birth control method like vasectomies or tubal ligation. However these methods are being improved all the time anyway and becoming less and less invasive, so I'm not sure this system is a better alternative. Like you I have difficulties believing there won't be some sort of development of chronic inflammation or other consequences. It may develop into something like chronic frustrated immune system depending on circumstances I guess.
ReplyDeleteThe question of how to reverse an immunological response is one that would not only allow for a contraceptive but also take care of allergies as well. If you could tell specific cells to not react to certain epitopes you could eliminate those that cause many of us much annoyance. What if you added to the epitope a delayed release of a radioactive atom. This would then cause the cell that reacted to the sperm or allergen to die. Since many B and T cells interact with the epitopes before the correct one is found you would some how have to cover up the atom maybe in a lead “blanket” and then some conformational change occurs and reveals the radioactive atom. This of course is extremely hypothetical but seems like a really cool way to go about it.
ReplyDelete