I'm trying to find the title of a movie from the 1980's or early 1990's that released in the US. It was a serious movie with more of an action vibe than straight horror - very Resident Evil-ish.
In the film, a facility of some kind - located outside a small town - goes into lockdown mode after a contagion gets released. As the government surrounds the facility and contemplates how to kill the contagion, the local sheriff sneaks into the facility in order to rescue his girlfriend or wife, who was an employee in the facility when it locked down. The contagion has turned everyone inside into zombie-like creatures, but the sheriff finds the girlfriend unaffected despite many close encounters with the zombies. In the end, it turns out that she's unaffected because
she's pregnant, and the hormones produced by her body render her immune.
Does this ring a bell with anyone?
Further Info: The sheriff was a Caucasian man in his late 30's or 40's with short dark hair - kind of a rugged looking guy. The girlfriend/wife was a Caucasian woman in her 30's or so with a short tomboy-ish haircut and dark hair. I could be wrong but I think the GF was a security officer at the facility.