A Vaccine Mystery Hits Older Americans

Bloomberg View , September 04, 2014

More than three-quarters of Americans believe vaccines for such diseases as measles, mumps, and whooping cough should be mandatory for children, a new Harris poll finds. The margin increases with age, with 88 percent of respondents over 69 years old and 83 percent of those 50 to 68 voicing support. People who remember the scourge of polio and who themselves may have suffered through such “childhood diseases” as mumps are, not surprisingly, more likely to want vaccines required for kids.

But when it comes to their own health, they aren’t as enthusiastic about a shot of prevention.

It’s been eight years since the Food and Drug Administration approved Merck’s Zostavax shingles vaccine for people over 60. The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices officially recommended it for the same group. Yet only about 20 percent of Americans over 60 have had the vaccine. (In 2011 the FDA also approved it for people over 50, but without a CDC recommendation insurers rarely cover it.)

Shingles, also called herpes zoster or zoster, occurs when the virus that once gave someone chickenpox reawakens after lying dormant in nerve tissue. Combining what feels like deep muscle aches with the sensation of burning skin, it can be excruciatingly painful. Having come down with shingles three years ago, I can personally attest to the agony. My economist husband, who developed the disease in early July, said early on that he would have paid at least $3,000 to avoid the experience. (Yes, this is the way we talk in the Postrel household.) After living with the (finally waning) pain for nearly two months, he’s upped the estimate to $5,000 -- a lot less than the roughly $200 the vaccine costs someone whose insurance doesn’t cover the shot.

So why don’t more people get it, especially those over 60 who could generally get it for free? Doesn’t it work? Or is there some horrible risk I don’t know about?

To find out, I arranged interviews with two leading experts: Stephanie R. Bialek, a medical epidemiologist for the CDC, and Hung Fu Tseng, a research scientist at Kaiser Permanente Southern California, who studies the safety and effectiveness of vaccines by doing large-scale data analysis on Kaiser’s electronic patient records.

More than 99 percent of people over 40 who were born in the U.S. have had chickenpox and are thus vulnerable to shingles. (You can also get shingles if you’ve had the chickenpox vaccine, but it’s much less likely.) The risk of coming down with shingles rises sharply after age 50 and increases with age. The incidence of shingles seems to be rising, but no one knows why; the theories put forward so far haven’t panned out. The increase began before Americans started getting chickenpox vaccines, for instance, and didn’t accelerate as those vaccines became routine.

Without the shingles vaccine, about a third of the population will come down with the disease at least once. (Debate still rages over the odds of recurrence once you’ve had it.) The vaccine cuts your odds in half. Call it a 15 percent chance.

But the real issue isn’t just whether you get shingles. For most people, the disease means a week or so of possibly itchy lesions and moderate pain -- unpleasant but not awful, especially since shingles isn’t contagious. (It can conceivably give other people chickenpox.) The problem is the potential complications. For 10 percent to 25 percent of patients, shingles affects the eyes, causing great pain and in some cases damaging vision. And in 15 percent to 20 percent of patients (and 100 percent of the Postrel household), serious shingles pain persists even after the lesions disappear, a condition known as postherpetic neuralgia, or PHN. For most of these patients the pain lasts less than three months but for an extremely unlucky few it can last a lifetime.

The complications, especially PHN, are the main reason experts including Tseng and Bialek recommend the vaccine. “Since we don’t know who will have this severe, long-term complication,” says Tseng, “if the preventive strategy is available, it will be a wise decision. Most of the cases can be recovered in 10 days. But we certainly don’t want to be the unfortunate one.” The vaccine reduces the chances of getting shingles in the first place and, should that fail, it cuts the chances of PHN in half.

Another factor is that shingles is both more dangerous and more likely in people with compromised immune systems, whether from HIV, immunosuppressant drugs or chemotherapy. (When I had shingles, my internist expressed surprise that the disease hadn’t hit when I was having chemo several years earlier.) A vaccine while you’re healthy lessens the risks if you later suffer a compromised immune system.

In a recent article in the journal Clinical Infectious Diseases, Tseng and his colleagues analyzed the records of more than 21,000 chemotherapy patients 60 or older and found they were 42 percent less likely to come down with shingles if they’d had the vaccine. Currently, immunocompromised patients don’t receive the vaccine, which contains a weakened or “attenuated” strain of the live virus and could theoretically make them sick. But an editorial in the same journal argued that the benefits for such patients are so great and the dangers sufficiently low that “the results of these and similar studies suggest that it may be time to review the current policy of excluding all immunocompromised persons from receiving zoster vaccine.”

For healthy patients, getting the vaccine seems like an obviously smart move. So why have so few people opted for it? The main reasons seem to be cost, inconvenience, and inertia. The vaccine is expensive, although for people over 60 it’s now covered under Obamacare plans as well as Medicare Part D. It has to be kept frozen, and many doctor’s offices don’t stock it. That means that physicians don’t routinely offer it to patients and people who want it have to seek out a pharmacy. (At Kaiser Permanente, where clinics keep the vaccine in stock and members receive it for free, 35 percent of those over 60 have been vaccinated.) And, of course, there’s inertia. It’s a lot easier to understand why someone should get a shingles vaccine if you’ve had shingles yourself. If you haven’t, the danger seems remote.

But what are the chances of getting shingles from the virus in the vaccine? Finding out was my hidden agenda when I interviewed Bialek and Tseng. In the online literature, all I could discover was a risk of a small outbreak of chickenpox-like sores around the injection site, but nothing about full-blown shingles. Yet my husband, healthy and about to turn 54, had gotten the vaccine on July 3 and by July 7, he had a textbook case of the disease. Lesions soon covered the left side of his back and wrapped around his side. How often does this happen? I wanted to know.

Essentially never, it turns out. Out of millions of vaccinated patients, there has been exactly one documented case of someone developing shingles with the genetically distinctive characteristics of the vaccine strain rather than the “wild type” zoster already common in the population. Even without genetic testing, both Bialek and Tseng were confident that my husband’s case couldn’t have been caused by the virus in the vaccine. The outbreak was just too quick. “You can’t get the vaccine strain in two or three days after the vaccine,” said Tseng. “It takes time for the virus to establish latency.”

He recalled a 69-year-old male patient who’d developed shingles two days after receiving the vaccine and thought that the illness must have been caused by the shot. “We tested the virus strain in his lesions,” he said. “It was wild type.”

So my husband was just incredibly unlucky -- even more unlucky than we’d thought. If he’d gotten the shot earlier in the year, he might have avoided months of pain (and about $250 so far in prescription co-pays). Even when he thought he’d gotten shingles from the vaccine, his advice was, “Run and get the vaccine!” Now that he knows he didn’t, he suggests you save time and drive.