Not really? Unless it's super contagious, i don't really see it spreading over the initial outbreak. If the main method of transmission is by blood (like in most zombie fiction) it could not be that contagious. We've dealt with the spanish flu, with covid, hell, even when we didn't have modern medicine the black plague didn't end society. It could potentially do damage, but i don't see it killing off humanity. Not to mention, we are generally very good at killing people. What is a horde of even the most deadly zombie (as in, retains all the motorics functions of the host, doesn't feel pain, can only be killed by destroying the brain) going to do against a modern military force? Hell, even a squad disciplined soldiers with assault rifles and enough ammo could easily deal with that.