If the MK-Virus was man-made, perhaps the reason artificial insemination fails to produce viable male offspring is because the same group that created it, and doesn't want a cure found, is deliberately sabotaging the sperm samples, which is something that's not possible during actual sex.
The Mk-virus, as described, has symptoms very close to Ebola, which has been known to kill in three days, if not less, except that the MK-virus is airborne, and as contagious as the common flu. A "perfect storm" nightmare scenario amongst the personnel of the Center for Disease Control. For a virus like that to be unleashed, all that's needed is for a flu virus and ebola virus to infect the same cell and have the viruses exchange genetic material, which is how viruses "mutate" in the wild. How the creators of the MK-virus made it gender-specific is a mystery, but a virus that virulent and contagious is not likely to remain gender-specific for very long.