When a PC decides they want to do an astral quest, if I have any time at all, I like to roleplay through it, and treat it as a real experience on that plane. If, by chance, someone contracted HMHVV on an astral quest because of the challenges they faced, what would happen to them physically? HMHVV is, to an extent, an awakened virus (see the increased propensity for magical skills among wendigo, for example).

Nothing. An astral quest isn't "real" in the sense that you can catch a virus. It would be the equivalent of an otaku catching HMHVV by running across genetic studies regarding it in some top-secret corp database.

On the other hand, it should make an interesting addition to the astral quest.

It also can have a mental/emotional impact on the character which can continue into the physical world. E.g. fear of dark places, which translates into +3 TN on all social skill rolls when in dark places, which gradually goes away over 3 months.

I'm the Astral Questor...

Here is why Adriaan the hermetic is worried:

During his astral quest, he sufferred a light wound from a Vampire version of himself. Before the end of the quest, he healed the light wound he had sufferred on his neck. After returning to his body, he found that he had a light physical wound on his neck. (I was conducting this astral quest from a level one power site, which is a contributing nuisance to the problem if nothing else).

HMHVV is a retrovirus. Shadowrun genetic theory dictates that a piece of genetic code carries with it a 'shadow' of a certain astral template. IF changing an astral template can have a corresponding effect on the genetic code, then a temporary change to my astral template might be able to effect local genetic changes... ie, produce some real HMHVV virus.

GM's choice on whether to screw me... any thoughts?

Your theory is a little backwards. Mana facilitates changes in DNA, but does noti cause them. Sort of like how gills only function properly in water. The structure of DNA creates a three-dimension analog to a fourth dimensional shape (the fourth dimension being in the astral), and thus allowing mana to pass through and activate changes in the DNA.

However, no exchange of genetic material can take place during an astral quest. So you can't get pregnant, or contract a retrovirus, even a magical one.

The physical manifestation of your wound has to do with a spiritual injury reflected back on you; unless a vampire came in while you were questing and bit you, you're not Infected.

Okay, I agree that is how its supposed to work, I was just outlining a possible way.

Negative effects, including death, loss of magic points, etc, are indeed possible during an astral quest.

Would it be possible to start to become a vampire --without-- contracting the HMHVVirus as a result of an astral quest?

It may cause psychosomatic problems, like he may think he needs blood to live and if he doesn't get his "fix" he may start to get sick. Or grow a fear of what ever it is he thinks Vampires should fear, like sun light or a cross(it may work on SR vampires but his mental derangement is stemmed from his memories so he may have the cross idea from old flatvids). Hell he might start desiring the need to live in a coffin. I don't really seen him contracting a virrus from astral space, until Ares developes one, the damage caused in the astral plane is just like casting a spell over your magic rating or what ever it is just your body getting beat up, being unable to handle the amount of mana being channeled into it.

So my opinion is no virus, maybe a lot of mental flaws like psychotropic ice on deckers.