There are so many conspiracy theorists in the market place about the origins of HIV BUT the biggest of all is Dr. Leonard Horowitz and Prof. Jakob Segal. The arguments of Prof Segal which is exactly what @ murchr is pointing at have to be considered together with an argument on the origin of SIV (cousin of HIV) in green monkeys. In real life scenario, chapter 6 of kenyan constitution should be read with other chapters not in isolation.
Now back to @ Murchr, Our bodies (mine and yours) harbour viral DNA acquired millions of years ago. For instance,i will give two examples (i) common cold is caused by a rhino virus but is not lethal (ii) Herpes simplex virus just wakes up one day and causes an ugly watery blister on your mouth and may stay silent for years before it pops up to cause more damage without killing the host.
I agree with the author that HIV is different. As you know, HIV attacks the 'army' and by army i mean CD4+ T cells and macrophages, whose work is to protect the cells. Ever wondered why we do not have a vaccine against HIV yet? because the virus is much clever than us. We actually need to change strategy on how to design our vaccines because the current strategies cause even more damage. In some cases the vaccine may even lead to new infection in experimental group compared to the placebo (control) group. The vaccine is safe on its own (how vaccines against HIV are designed is a discussion for another day). The reason why the group receiving the vaccine may be at risk is that the vaccine will activate the cells to finish off the virus when it is infecting the body BUT HIV infects with ease these activated cells. These are the questions we need to ask these people but i have no problems with development of vaccines.
On your last question, @ Murchr i am not an oncologist but since i suppose i had some good training in bio-medical sciences i will just comment. We got two types of cells: (i) Germ cells (sperms & ova) (ii) Somatic cells (any other cells not germ cells kama vile cells making the skin, bones, macho etc etc). Lifestyles do influence and expose our somatic cells to all sorts of stress and this may lead to cancer. Mutations on germ cells are so dangerous since can be passed on to the next generation while mutations on somatic cells are not. Just another reason why you should protect your makende at all time.
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