There may be certain mission-critical, non-internet-connected machines for which it's still safer not to install updates, but for the average doctor's workstation it will probably become the norm to install Windows patches.
Where I live, doctors have more freedom in how they run their clinics and IT. That probably causes its own problems, but at least they're free to run a modern version of their OS and keep it patched. This kind of virus wouldn't affect us the same way since there's no top-down tech policy which prevents individual doctors from following good security practices; in fact, if you just follow all the recommended settings when installing Windows/macOS, you'll end up with automated patching by default.
So if you really want an epidemiological analogy, maybe the best one is a monoclonal, monoculture crop (e.g. the Gros Michel banana) being decimated by a pathogen which has just evolved the ability to infect it: take down one banana, and you take them all. Take down one English doctor's computer...