I read that article before. The fatal weakness of its reasoning is that it only focuses on fatalities. The reality is that even if you got ill with the flu, you almost never died (under 0.1% fatality rate). Even the super-fatal pandemic flu of 1918 was about 5% fatal among those sickened. I doubt if it is feasible to get a statistically significant count of fatalities in a controlled study sample.

But even if you do not die, flu is pretty costly. It is costly in the time you spend miserable, sick and out of action. It is costly to the colleagues, friends and family that you in turn sicken. It is costly to society as a whole. Vaccines either prevent that sickening altogether or reduce its severity. That makes vaccination campaigns valuable to society as a whole -- even to the unvaccinated -- because any flu case prevented or shortened will eliminate yet another infection source. Since flu spreads, well, virally, stopping even one source is significant. That's why govt agencies tend to be on board, because they are worried about the health of the overall society.

I know you hate Java, but do reconsider. Since you have established your .NET skills, you will probably cover the vast majority of the universe of software job opportunities if you can add Java to the list. Of course there is a lot valid stuff outside of .NET and Java, but those are the dominant players, professionally speaking.

You won't be locked into the Java language. The Java ecosystem is much larger than that: the Java class libraries, of course, but also Spring, Hibernate, J2EE, the Apache goodies, Eclipse, debuggers, profilers, monitoring etc. If you expect to integrate your software with a future unknown codebase -- perhaps by acquisition or merger -- there is a good chance it will be Java-based.

Ruby, Python, JavaScript and other languages do run on the Java JVM, but I suggest taking a look at languages that really sprung up from Java, like Groovy and Scala. Groovy appeals to the dynamic typing camp, and Scala to the static typing camp. The advantage with these languages is that they integrate into the Java platform just about as well as the Java language itself. You can write real Java-visible classes in these languages that integrate seamlessly with the rest of the Java platform, including annotations, generics and enums. Other languages can run in the JVM and call Java classes, but it's likely a one-way street. Java classes cannot call, say, a JavaScript class (JavaScript has no classes!).

My own experience has been with Groovy, which claims Smalltalk, Ruby and Python as its inspiration. It's much more productive, powerful and readable than Java. Yet it integrates well with all things Java. And yes, it's production code deployed on Linux.