Adults proving a tough target for shingles shot
■ Attempts to reach adults with a new vaccine provide a case study on the difficulties of immunization beyond the childhood schedule.
By Susan J. Landers — Posted Feb. 11, 2008
Washington -- What if researchers develop an effective vaccine but nobody uses it? That's the fear of some in public health as disappointing data emerged from a new Centers for Disease Control and Prevention survey indicating low immunization rates for some adult vaccines, particularly herpes zoster, or shingles.
Only 1.9% of people older than 60 -- the group targeted for the shingles vaccine -- have received protection from the painful condition, according to results from the CDC's National Immunization Survey, released at a Jan. 23 news briefing.
It's the first time adults have been included in the survey, said Anne Schuchat, MD, assistant surgeon general and director of the CDC's National Center for Immunization and Respiratory Diseases. The survey's focus always had been on children because they were the recipients of the vaccines. Times have changed and, with Food and Drug Administration approval of several adult vaccines, the agency is urging physicians to use them. In fact, this effort is viewed by many as the new frontier in public health -- but delivery challenges and other issues are emerging.
Physicians' groups, including the AMA, have encouraged the use of adult vaccines, advising physicians to get immunized and to encourage patients to do the same.
Michael N. Oxman, MD, professor of medicine and pathology at the University of California, San Diego, would like to see more adults receive the shingles vaccine. Dr. Oxman is also the national chair of the Shingles Prevention Study.
"There are more than 1 million new cases of shingles each year," he said, speaking at the briefing. Half are among those 60 and older, the group for whom the vaccine was approved.
Meanwhile, Merck, the preventive's manufacturer, plans to seek FDA approval to market the vaccine in the future to those age 50 to 59, said a company spokeswoman.
Everyone who has had chickenpox is at risk for shingles, Dr. Oxman noted. Shingles itself is painful, but even worse can be postherpetic neuralgia, which may follow the initial outbreak, causing life-altering pain that can sometimes last for years. PHN is resistant to treatment, he said.
The vaccine can reduce the risk of shingles by 51%, Dr. Oxman said, and it can reduce the risk of PHN by 66%.
The reasons why the vaccine has not been used even more broadly are varied, and some physicians aren't surprised the take-up rate is low. For one thing, it was approved only in May 2006. "There are always questions about new vaccines, and this is the first new vaccine for adults in some time," said John Toney, MD, professor of medicine at the University of South Florida College of Medicine, who has researched and written extensively on shingles.
Since the CDC had, as of mid-January, not yet published recommendations in its Morbidity and Mortality Weekly Report that the vaccine be given, some federal and private payers are still waiting for that signal. "That's when insurance companies and the federal government get more interested," Dr. Toney said.
The James A. Haley Veterans' Hospital in Tampa, Fla., where he is director of infectious diseases clinical research, has been among those sites waiting for publication before ordering the vaccine.
"I get asked all the time about when we'll get the shingles vaccine," Dr. Toney said. "I tell them, 'Your guess is as good as mine.' "
Plus, there is no mechanism similar to the Vaccines for Children Program that would cover the cost for low-income older people. And the vaccine is expensive -- Merck sells it for about $150 per dose.
Although the vaccine is covered under Medicare Part D, that system was designed with pills and not vaccines in mind, and for paying pharmacists, not physicians, causing reimbursement complications. One way for physicians to get paid is to charge patients who then can be reimbursed by Medicare. But it is a large expense for low-income people.
The fact that the vaccine, made from live attenuated virus, must be kept frozen compounds the access problems. Patients sent to a pharmacy with a prescription for the vaccine are liable to return to the physician's office with a thawed dose and a virus that is dead on arrival.
"If you administer a dead, live vaccine, it's like giving a shot of saline," Dr. Oxman said.
The obstacles are frustrating to physicians. "We developed a fine vaccine, and then we have a process that prevents doctors from getting it to patients," said William Schaffner, MD, professor and chair of the Dept. of Preventive Medicine at Vanderbilt University School of Medicine in Nashville, Tenn.
Dr. Schaffner, also vice president of the National Foundation for Infectious Diseases but speaking on his own behalf, related that Vanderbilt found a way around the problem. The university developed a system in which pharmacists administer the injections.
"The doctor writes a prescription, patients take it to the outpatient pharmacy, and that's where they get the inoculations," he said. "We had to train our hospital pharmacists to do this, and we did it specifically for the shingles vaccine."
This route may not be widely available because of varying state laws.
Until resolutions for the various issues are at hand, giving the vaccine can be "a real challenge," Dr. Oxman said.
People also think 51% is not a terrific effective rate, Dr. Toney said. "But when you look at those numbers, they are pretty much on par with what we get with influenza vaccine and pneumococcal vaccine for adults."
Plus, the vaccine is more effective at preventing PHN.
"It's great if you can prevent a case of shingles, but if you can prevent a case of PHN, then I think you've got a great vaccine to look at," Dr. Toney said.