Vaccine Shortages

by Food and Drug Administration (FDA)

Judi Chase says she's not winning any popularity contests these days. As a program manager for vaccines at the Texas State Department of Health, she's used to fielding questions from health-care providers who want to know why their vaccines are late and what she's going to do about it. Her department coordinates the vaccine supply for about 3,000 providers in the state's Vaccines for Children program. "I try to tell them it's not us," Chase says.

She also understands the providers' frustration. "It's hard enough to get people vaccinated the first time," she says. "So if they're told the supply is out, it's especially difficult to get them back." The biggest supply challenges for Texas over the past year have been with the chickenpox vaccine and with the pneumococcal vaccine, Prevnar. And while the chickenpox vaccine supply is returning to normal, Prevnar remains a problem. "We need about 80,000 doses of Prevnar a month, and we get about 15,000 doses a month from the manufacturer," Chase says. One strategy has been to take the available doses and divide them up so that various providers each can have a small percentage. "But then when it's gone, it's gone," she says.

When it's gone, doctors have to track patients and tell them to come back when the supply is back up. In critical situations, they send patients to other providers. Dianna Heyer, R.N., nursing service coordinator at the Macon County Department of Health in Decatur, Ill., says doctors in her area who don't have tetanus and diphtheria (Td) vaccine have referred patients with wounds to the county clinic. The vaccine prevents a neurological disease known as lockjaw and a life-threatening respiratory illness.

"We've been able to give the shot to people with wounds," Heyer says, "but we couldn't give routine Td boosters for the last year." For example, Heyer's clinic couldn't give boosters to children in ninth grade last year. As a result of recent vaccine shortages, which have mostly affected childhood vaccines, several states temporarily suspended school entrance requirements for immunizations.

Td boosters are normally given at age 11 or 12 with a subsequent booster given every 10 years, according to the vaccine schedule recommended by the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices (ACIP). Now that the Td supply is back to normal everywhere, Heyer says they will probably hold special clinics this year so the children who missed shots last year can catch up.

There are many reasons for the shortages. A major reason is the fact that there are relatively few manufacturers in the vaccine business. It's also difficult to make vaccines; from start to finish, a particular batch of a given vaccine requires roughly a year of production time. Unlike most drugs, vaccines are produced from living cells and organisms. Most require growing the immunizing agent, whether it's bacteria or viruses, in a production facility where growth conditions are complex.

William Egan, Ph.D., deputy director of the FDA's Office of Vaccine Research and Review, says, "No disease outbreaks have resulted from the shortages, but children not being fully immunized is always a concern." Fortunately, projections by manufacturers indicate that serious shortages of several vaccines are easing. Here's an update on vaccines that have been in short supply:

Diphtheria and Tetanus Toxoids and Acellular Pertussis (DTaP): Calling it a business decision, Wyeth Lederle of Pearl River, N.Y., stopped making DTaP in 2001. This left only two manufacturers of the vaccine, Aventis Pasteur of Swiftwater, Pa., maker of Tripedia, and GlaxoSmithKline of Philadelphia, Pa., maker of Infanrix.

In addition, Aventis Pasteur made changes to remove a mercury-containing preservative called thimerosal from DTaP and had to go through FDA clearance. The company made the change by switching from multi-dose to single-dose packaging. And this uses a greater amount of vaccine per dose to make sure the full dose can be drawn from a vial. Glaxo's DTaP product was already thimerosal-free.

During the shortage, ACIP recommended that if providers didn't have enough DTaP to vaccinate all children with the standard five doses, they should make it a priority to vaccinate infants with the first three doses. Normally, children receive one dose each at ages 2 months, 4 months, and 6 months, followed by another dose at age 15-18 months and the final dose at age 4 to 6.

The DTaP supply has returned to normal, in part, because the FDA licensed a new DTaP vaccine (DAPTACEL) by Aventis Pasteur in May 2002. DAPTACEL is indicated for immunizing children ages 6 weeks to 6 years.

Measles, Mumps, Rubella (MMR): According to Merck & Company, West Point, Pa., temporary shortages of some vaccines they produce, including the MMR vaccine (M-M-R II), are due to two voluntary interruptions in their manufacturing operations. Merck voluntarily closed one facility after the FDA raised issues during a routine inspection. Another facility closing was already scheduled and took longer than expected.

During the shortage, ACIP recommended administration of the first dose in the 2-dose MMR regimen at age 12-15 months and deferral of the second dose that's recommended at 4-6 years. The supply is now back to normal.

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