I noticed that you can't get infected by being around dead body's of the infected and I dislike this because if the combine/rebels just kill the zombies before they can approach, the virus couldn't spread but the original T-virus in the Gbomb addon the virus could spread by just being around the dead body's of the infected and rebel/combine like being around the dead body's of what they killed so the virus could easily infect them and then the combine/rebels now have more zombies to deal with and less firepower to kill the new threat and over time could wipe them all out.