ANN ARBOR, MI – An ongoing national shortage of a vaccine that prevents meningitis and pneumonia in children has left doctors scrambling to provide even the minimum number of shots, and has exposed gaps in the nation's "patchwork" vaccine system, the first-ever in-depth study of the problem finds.
Three-quarters of 405 doctors' offices surveyed in 12 states reported problems with consistently getting enough of the potentially life-saving vaccine known as Prevnar, and more than half said they had run out completely at least once in the past year, according to a study in the February 5 issue of the Journal of the American Medical Association.
The survey was conducted by researchers at the University of Michigan Health System's Child Health Evaluation and Research (CHEAR) Unit, who have funding from the Centers for Disease Control and Prevention to conduct studies of vaccine issues.
They found great variation among states in availability of Prevnar, or heptavalent pneumococcal conjugate vaccine. Many of the doctors' offices said they had borrowed Prevnar from public stocks reserved for poor and uninsured children in order to vaccinate privately insured children, or vice versa, as their stock ran out.
"For parents, this means that depending on what state you're in, and the source of vaccine for which you are eligible, you may not have been able to protect your child against these preventable, potentially serious diseases," says lead author Gary Freed, M.D., M.P.H., the Percy and Mary Murphy Professor of Pediatrics and Child Health Delivery in the U-M Department of Pediatrics and Communicable Diseases.
The CDC and the American Academy of Pediatrics recommended Prevnar for children under age 2 in mid-2000, after its approval by the Food and Drug Administration that year. The Prevnar shortage began in 2001, and may continue through 2003, due to high demand and manufacturing problems.
In September, 2001, the shortage led the CDC to alter its recommended vaccination schedule, prioritizing the vaccine supply to ensure infants got at least two of the four recommended doses and therefore some protection.
But the CDC's policy change came too late to help many practices alter their Prevnar use, because many were already out of stock or nearly so. At the time of the survey interviews, in October and November 2001, only a quarter of practices had cut the number of injections per child to two or limited the vaccine to high-risk children.
"We've never had a shortage like this before, and this one has persisted," says Freed, who as director of the Division of General Pediatrics oversees primary-care pediatrics at UMHS.
The efforts by doctors' offices and clinics to make sure that infants and toddlers got at least some Prevnar injections shows how important the vaccine is considered, Freed explains.
The seven strains of Streptococcus pneumoniae bacteria for which the vaccine provides protection are common causes of potentially deadly cases of bacterial meningitis, blood infections and pneumonia. Cases of those diseases have dropped off since the vaccine was introduced.
The bacteria also cause millions of ear infections, or otitis media, each year, though they're responsible for only a fraction of all ear infections. An FDA panel recently recommended that Prevnar be approved to prevent ear infections caused by pneumococcal bacteria.
The U-M researchers designed their study to get a snapshot of how and why the Prevnar shortage was affecting physician practices. They interviewed clinical staff involved in vaccine ordering at practices in urban, suburban and rural parts of California, Florida, Kansas, Kentucky, Louisiana, Maryland, Michigan, New York, Oregon, Pennsylvania, Texas and Wisconsin.
The 12 states were picked for geographic diversity, and practices were selected that take part in the CDC's Vaccines for Children program. Through VFC, state governments buy vaccine and provide it to doctors to be given to children on Medicaid, uninsured children, and Native Americans and Alaska Natives. Some states, including a few in the study, also buy vaccine for children whose insurance doesn't cover vaccines.
None of the states in the study is a "universal purchase vaccine" state, meaning that the state government purchases vaccine that is provided to all children, including those with private insurance.
Only 14 U.S. states have universal vaccine purchasing programs. All the others have some form of a public system for some children, but individual physicians and clinics must purchase vaccine themselves through distributors and manufacturers for most or all privately insured patients. Some states restrict physicians from vaccinating a privately insured child with vaccine "borrowed" from their stock of publicly funded vaccine, even in times of shortage.
This variation in state practices for handling the public vaccine supply, combined with the variety of private vaccine sources, gives the United States its "patchwork" vaccine system, says Freed.
Eighty percent of practices reported problems with obtaining a consisted supply of private Prevnar, while 70 percent said they had trouble getting public supplies of the vaccine. Just over half reported they had been out of public Prevnar at least once in 2001, and 64 percent had been out of private Prevnar at least once. In 10 states, more than half of all practices had been out of private Prevnar for a week or longer.
Only two of the 12 states showed a substantially higher proportion of offices that had been out of stock of public vaccine compared to private vaccine. In six states, public vaccine was less frequently out of stock than private vaccine.
Vaccine makers are bound by their government contracts to fulfill minimum orders for public vaccine, which accounts for more than half the vaccines for children. But public vaccine is often sold at a lower price than the vaccine commands on the open market.
Even so, Freed says, "We found no concerted effort by the manufacturer to shunt vaccine to either the public or private marketplace. There was no pattern of disparity between the public and private supplies."
Indeed, the individual states' decisions about how much vaccine to stockpile in case of shortage, and from which vaccine distributors to buy, may have made a major difference in the availability of vaccine in a particular state, the researchers say.
Part of the problem at the physician practices was awareness that a national shortage was in effect; more than half of practices that had experienced any sort of Prevnar supply problem said they had only become aware of the shortage when their supply was interrupted.
Now, as manufacturer Wyeth forecasts an increase in Prevnar production in 2003, and the easing of the shortage, Freed notes that many parents will have to play "catch up" with their child's Prevnar doses. And he hopes vaccine policy makers will look at the Prevnar situation for lessons for the future.
"Our findings show how much variation there is in the distribution and supply of a vaccine during a shortage," concludes Freed. "We hope that in the future, government vaccine purchase contracts will be negotiated to ensure an adequate public supply. And we hope states will examine their own vaccine purchasing practices and policies, and get further guidance from the CDC."
Besides Freed, the study's authors are assistant professor of pediatrics Matthew Davis, M.D., M.A., and Sarah Clark, M.P.H., the associate division director for research in General Pediatrics.
For more information on vaccination, parents may call the CDC Vaccine Information Hotline at800-232-2n 522 (English), or 800-232-0233 (Spanish).
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