Recommendation is an established concept when it comes to vaccines. When you travel to country X then it's recommended to get vaccines for A, B, C. Or when you

Recommendation is an established concept when it comes to vaccines. When you travel to country X then it's recommended to get vaccines for A, B, C. Or when you have age N and gender G you are recommended to get vaccines D, E, F. And so on. In many instances, whether your insurance pays or not depends on whether the vaccine is recommended for you by official authorities. At least in Germany, a doctor if they deem it useful for your health is still authorized to order the vaccine and put it into your arm, but you have to pay the bill for that. Sometimes insurances also pay for non-recommended vaccinations. The same goes for therapies for diseases. Each disease has a list of therapies/drugs available that are officially recommended by authorities, and usually what insurances pay for is based on that, but exceptions exist (in both directions).