Basically the girls turn into sluts because of virus and protag was looking for the girl in page 38. He saw a bunch of girls raping guys along the way.
There was an explosion at a pharma company where the MC's wife works, he sneaks into the building to find her. The guy he rescues on page 26 is his wife's boss. They go to the lab to get a vaccine and the MC keeps everyone "busy" while the other guy works. In the end they're able to develop a vaccine, but the infected women will never recover, so the MC's wife and others now live in his basement as his sex pets. Happy end.