Good health is only affordable—for the majority of the population—if it is covered by insurance. An excellent case in point is the vaccine for shingles (herpes zoster).

Shingles is the revisiting of the chicken pox virus. The virus lives in the body since the first episode of shingles as a child, and then flares up during later adulthood to give shingles.

Shingles is rarely life-threatening, but it is immensely painful and debilitating, and not very amenable to treatment. Most patients end up suffering intense pain and can have complications that last for months. Shingles will attack up to 1/3 of the population.

So doctors and patients alike were delighted when a shingles vaccine was approved in 2006. It prevents many cases of shingles, and significantly decreases pain in the others.

It is safe enough and effective enough to be recommended by the CDC as a standard vaccine for adults 60 and older. It is now one of components of preventive medicine, taking its place alongside colonoscopy, mammograms, flu shots and pneumonia vaccines.

Except there is a problem: cost and coverage. The vaccine costs about $200 and most insurances do not cover it. (For comparison, seasonal flu shots cost about $20).

An article in the Annals of Internal Medicine recently found that less than 10% of people who were eligible for the shingles vaccine received it. The major barrier—no surprise—was that it wasn’t covered by insurance.

This highlights the issue of how medical care is determined by insurance companies (both private and Medicare), rather than by medical recommendations and scientific data.

Of course there are financial limits on what our system can afford. However, it seems that primary care interventions should get priority. Primary care is the first (and often the only) line of defense for most people’s health. This is something that is surely ripe for reform.

Danielle Ofri is an internal medicine physician and author of What Doctors Feel: How Emotions Affect the Practice of Medicine.