Globally, it would be fine even if the science isn't strictly accurate, given that you already have to cut round the corners to make zombies sound plausible. I'll make an effort to nitpick, and you take what seems pertinent out of the list:
"After attempting numerous tests, theories, and every trick in my book. My diagnosis has still come up inconclusive."
- Merge the two sentences, as the first is a fragment.
- Diagnosis probably isn't the word you mean. All I can think up in its place is research, but you may find better.
"What we do know is that the virus isn’t airborne, doesn’t need air or water, and can survive in the vacuum of space."
- Viruses don't need air or water as a general rule, and don't fear vacuums either. Whether a virus can go in space (where hosts are very scarce) isn't the first concern of biologists. If you want to mention space, you may want to say it as an hyperlative: "It has such a resistance to UV light and other radiation that it could even survive in space!" (viruses normally being too sensitive to light to survive in space)
"The main bulk of the virus seems to reside in blood cells, and salivary glands."
- Main bulk sounds redundant to me, but maybe that's just me.
- Sciencey note: if the virus had an affinity for epithelial cells, it would infect the inner layer of blood vessels and therefore be very concentrated in blood, and every mucosa, making it present in the mouth too. Since it hasn't been studied for long, finding what kind of cells it replicates in is more likely if there is only one.
"It has now since mutated and seems to need a certain x-factor in which I am unable to duplicate."
- If injecting it into a new host kills it within a few minutes, it doesn't seem to be missing any "x-factor". Do you mean its previous behavior couldn't be reproduced?
- When a virus mutates, the previous string still exists, so you'd still have some flu-like cases and some deadly cases. If all the flu cases turn deadly after a time, then it was part of its life-cycle all along.
"When injected into dead tissue cells the virus becomes dormant."
- Losing its infectious nature after being in dead tissue for a while is normal behavior for a virus, as they need live hosts. Since the scientist isn't aware of the reanimation stage yet, he wouldn't stress it.
"Unfortunately the mice at my disposal can’t seem to facilitate in which it needs to display the symptoms or cellular behavior that humans are experiencing."
- I find this sentence confusing.
"So I am currently unable to conclude ON any of my findings."
Here. As I said, I made an effort to nitpick, so don't be alarmed by the number of comments I left! You dismiss the ones you don't find useful and that's all.