Local medical facilities have thousands of software upgrades available to them that they don't use. Many still use paper.
The problem is not waiting around for someone to develop something better -- it's the deeply conservative work culture in medicine. Being conservative is good, in the sense that you wouldn't want your doctor jumping onto every new SaaS startup with questionable HIPAA compliance, and because it's easy to botch digital migrations of records, but a lot of doctor's offices in the US are 30-40 years behind the cutting edge of (non-medical) advancements. Many hospitals stopped using pagers in the last few years.
As for epidemiologists, they're programmers already if they went to school recently, and if not, they have lots of programmers available from their employers.
I have tried many times to "donate" my software skills to the public sector, and it's just impossible. Lots of other people will dip their toe into it and then quit, and the orgs are very wary of that. They're also so busy and under-funded they don't even have time to accept help from people like us.
If you want to do something useful for the world and medicine, I would suggest finding some widely-used FOSS epidemiological libraries and contributing to them. Making FOSS contributions is great for your resume, fun, and likely the best way to use your skills efficiently to make the world a better place (even though it may sound kind of dry).