CDC currently recommends routine immunizations  against 11 childhood diseases: diphtheria, tetanus, pertussis (whooping  cough), Haemophilus influenzae type b (most commonly meningitis),  hepatitis B, measles, mumps, rubella (German measles), invasive  pneumococcal disease, polio, and varicella (chicken pox). The federal government is also responsible for ensuring the safety of the  nation’s vaccine supply. Shortages Prompt Actions to Reduce Immunization Requirements

Recent vaccine shortages have necessitated temporary modifications to  the recommended immunization schedule and have caused states to scale  back immunization requirements. In general, these states have  reduced the immunization requirements for day care and/or school entry  or have temporarily suspended enforcement of those requirements until  vaccine supplies are replenished. While it is too early to measure the effect of deferred vaccinations on  immunization rates, a number of states reported that vaccine shortages  and missed make-up vaccinations may take a toll on coverage and,  therefore, increase the potential for infectious disease outbreaks. Production Problems - Manufacturing production problems contributed to  the shortage of certain vaccines. This was the case with a newly licensed vaccine, pneumococcal conjugate  vaccine (PCV), which protects against invasive pneumococcal diseases in  young children. While the recent shortages have been largely resolved, the vaccine supply  remains vulnerable to any number of disruptions that could occur in the  future—including those that contributed to recent shortages and other  potential problems, such as a catastrophic plant fire. While FDA has mechanisms  available to shorten the review process, they are not used for most  vaccines under development. As part of its  mandate to study and recommend ways to encourage the availability of  safe and effective vaccines, the National Vaccine Advisory Committee  formed a work group to explore the issues surrounding vaccine shortages  and identify strategies for further consideration by HHS. In 1993, with the establishment of the VFC  program, CDC was required to purchase sufficient quantities of pediatric  vaccines not only to meet normal usage, but also to provide an additional  6-month supply to meet unanticipated needs. Even if CDC decides to stockpile additional vaccines, the limited supply  and manufacturing capacity will restrict CDC’s ability to build certain  stockpiles in the near term.
What GAO Found

Vaccine shortages began to appear in November 2000, when supplies of the tetanus and diptheria booster fell short. By October 2001, the Centers for Disease Control and Prevention (CDC) reported shortages of five vaccines that protect against eight childhood diseases. In addition to diptheria and tetanus vaccines, vaccines to protect against pertussis, invasive pneumococcal disease, measles, mumps, rubella, and varicella were in short supply. In July 2002, updated CDC data indicated supplies were returning to normal for most vaccines. However, the shortage of vaccine to protect against invasive pneumococcal disease was expected to continue through at least late 2002. Shortages have prompted federal authorities to recommend deferring some vaccinations and have caused most states to reduce or suspend immunization requirements for school and day care programs so that children who have not received all mandatory immunizations can enroll. States are concerned that failure to be vaccinated at a later date may reduce the share of the population protected and increase the potential for disease to spread; however, data are not currently available to measure these effects. Many factors, including production problems and unanticipated demand for new vaccines, contributed to recent shortages. Although problems leading to the shortages have largely been resolved, the potential exists for shortages to recur. Federal agencies and advisory committees are exploring ways to help stabilize the nation's vaccine supply, but few long-term solutions have emerged. Although CDC is considering expanding vaccine stockpiles to provide a cushion in the event of a supply disruption, limited supply and manufacturing capacity will restrict CDC's ability to build them.