Minnesota Medicine

Published monthly by the Minnesota Medical Association
February 2002/Volume 85

Childhood Vaccines - What's New?

By Lynn Bahta, R.N., B.S.N., Margaret Roddy, M.P.H., and Diane C. Peterson

The only constant in the world of immunization is the ever-changing nature of the field. Although the routine childhood schedule has changed very little in the past year, vaccine shortage, vaccine risk communication and safety issues, and the expansion of an immunization registry have created challenges and opportunities for providers. The following information is a brief overview of current issues.

2002 Childhood Immunization Schedule 

The Minnesota Department of Health (MDH) Immunization Practices Task Force has approved a childhood immunization schedule for 2002. The only programmatic change to the 2002 schedule is the recommendation that the first dose of hepatitis B vaccine be given at birth. This year’s harmonized immunization schedule for the United States has been modeled after the Minnesota schedule. Copies of the Minnesota schedule can be downloaded from the MDH Web site www.health.state.mn.us/immunize or ordered by calling the MDH’s Immunization Hotline at 800/657-3970 or 612/676-5100.

Vaccine Spot Shortages and Delays 

Delays and shortages are occurring throughout the United States and have affected the vaccine supply in Minnesota as well. The reasons for these shortages include, but are not limited to, withdrawal of vaccine products from the market; removal of thimerosal mercury-based preservative from vaccines; enforcement of Good Manufacturing Practice (GMP) issues by the Food and Drug Administration (FDA); and unanticipated demand for certain products. Some of the specific issues and the vaccines affected are detailed below.

Tetanus and Diphtheria (Td) Adult Formulation 

In December 2000, Wyeth Lederle Vaccines announced its intent to stop production of Td. Aside from a very limited production of Td in Massachusetts, Aventis Pasteur is now the sole national producer of Td. Aventis has increased its production capacity; however, because Td production requires 11 months, adequate inventory is not expected to be restored before midyear of 2002.

The Advisory Committee on Immunization Practices (ACIP), a 15-expert panel of the Centers for Disease Control and Prevention (CDC) National Immunization Program, has provided national recommendations for prioritizing the limited supply of Td vaccine. They recommend that clinicians should 1) reserve Td vaccine for use in wound management, foreign travel, patients with an incomplete primary series, and pregnant women; and 2) defer routine boosters for adolescents and adults until supplies are restored.1 The Minnesota commissioner of health has waived the 7th-grade school requirement for 2001–2, and is also expected to do so in 2002–3. 

Diphtheria, Tetanus, and Acellular Pertussis (DTaP) 

With the withdrawal of both Wyeth Lederle Vaccines and North American Vaccines from the production of DTaP, the industry was left with just two manufacturers (Aventis Pasteur and GlaxoSmithKline). Competing production priorities for Aventis Pasteur tetanus-containing products resulted in a withdrawal of their government contract for DTaP. This left GlaxoSmithKline as the only source for publicly funded DTaP. Additionally, the Aventis Pasteur product, Tripedia, was reformulated in order to eliminate the preservative thimerosal. Until Aventis can rejoin the public market, spot shortages will occur in public sector clinics (i.e. clinics relying on Minnesota Vaccines for Children [VFC] vaccine).

Inventory of DTaP through the federally funded Vaccines for Children program has been erratic in Minnesota. Providers should prioritize available vaccine for the first three doses of the infant series; if their inventory is insufficient, ACIP recommends that the 4th dose of DTaP be deferred. If supply remains inadequate after suspending the 4th dose, providers should consider suspending the 5th dose.2

Pneumococcal Conjugate Vaccine (PCV7) 

The 7-valent pneumococcal conjugate vaccine Prevnar, marketed by Wyeth Lederle Vaccines, was licensed in February 2000 for use in infants and toddlers. Demand for the product quickly exceeded manufacturing projections and shortages have developed nationwide. In previous newly introduced vaccines, uptake was slower, and production was able to meet demand. This was not the case once Prevnar received FDA approval. Clinicians did not hesitate to include this vaccine in the infant vaccination schedule and also administered it to at-risk children between 2 and 4 years old. 

In addition, GMP issues with the FDA have led to difficulties in getting the product released. In Minnesota, distribution has already been reduced. Recently released ACIP recommendations call for prioritization of doses until the vaccine shortage is resolved. They state: “For infants who receive their first dose before age 6 months, vaccination with a maximum of 3 doses is recommended; the fourth dose should be deferred. All health care providers should reduce the number of vaccine doses used and ordered, regardless of their current supply, so that vaccine is more widely available until supplies are adequate.”3 Resolution of PCV7 shortage is expected in late spring 2002.

Varicella and Measles, Mumps, and Rubella (MMR) 

According to Merck & Co, the manufacturer of MMR and varicella vaccine, distribution of these vaccines will be delayed. Resolution of this delayed distribution is not expected before mid-2002. In addition, some delays may also occur with PedvaxHib and the pediatric and adolescent hepatitis B formulations. 

Catch-up Schedules

Providers deferring vaccination because of these delays and shortages should put a reminder system in place—it could be something as simple as a tickler file to identify and recall those infants and children whose vaccinations were postponed.

Vaccine Risk Communication 

The growing ease with which the general public can access information on the Internet creates the potential for an ever-widening gap in reliable vaccine information. It is becoming more critical for physicians and other health professionals to be aware of the circulating misconceptions, to have resources for parents readily available, and to be prepared to engage in discussions regarding parental concerns about vaccines and childhood vaccination. 

Several resources address parental concerns regarding vaccination. The National Immunization Program of the Centers for Disease Control and Prevention (www.cdc.gov/nip) has numerous sites that address common concerns and features a different special topic daily. The National Immunization Information Network (www.immunizationinfo.org) has a resource kit, “Communication with Patients about Immunization,” available online for providers. For a more comprehensive list of related resources, see the Immunization Action Coalition’s Web site on vaccine safety, www.immunize.org. (See “No Shots for My Child!, p. 24, for more information and tips for addressing parents’ concerns.)

Minnesota’s Immunization Law 

During the 2001 legislative session, the MDH attempted to update the school immunization law by proposing that the commissioner of health be given authority to modify school immunization requirements to align them with the most current recommendations of the major national organizations, such as the American Academy of Pediatrics, the American Academy of Family Physicians, and the ACIP. 

This proposal was met with a great deal of opposition from individuals conscientiously opposed to vaccination. In the end, the newly enacted law provides the commissioner of health with the authority to modify the requirements to the school immunization law using the rule-making process.4 This rule-making process represents a compromise between delegating authority to the commissioner to make modifications to the school immunization requirements and having all changes go through the legislative process. The rule-making process is an attempt to allow enough flexibility to ensure that the school immunization law can be kept up-to-date with current practice standards and vaccine developments, while at the same time ensuring public input. Any proposed changes to the school law must first be part of the immunization requirements of each of these organizations: the ACIP, the American Academy of Family Physicians, and the American Academy of Pediatrics. The conscientious exemption provision, which requires parents to sign and notarize an exemption form if they choose not to have their child vaccinated, remains in effect and would not be affected by any rule making. 

The increasingly vocal opposition to vaccines influenced the recent changes to the immunization law. Information disclosure requirements have been added to the law. All written information about immunization requirements must include information on the exemptions allowed in Minnesota; this information must be the same size and font as the other information on the page. Additionally, immunization providers are required to provide information about what vaccines are required by law, what exemptions are allowed, and what vaccines are currently recommended by professional organizations. As required by federal law, the parent or guardian must receive a copy of the specific Vaccine Information Sheet (VIS) for each and every dose of vaccine the child is to receive. Materials can be obtained via the MDH Web site or by calling the Immunization Hotline.

Minnesota Immunization Rates

The MDH conducted two comprehensive, retrospective immunization surveys that reviewed the immunization records of all kindergartners (n = 70,000 children) entering school in 1992 and 1996 (Figure 1). These surveys are among the most comprehensive public health surveys ever undertaken in this state and perhaps in the country.5 The results provided specific direction for immunization programs across the state by identifying locations in the state—by ZIP codes and school districts—where immunization levels were low. A key finding in both surveys was that pockets of low immunization levels could be found all across the state—even in areas where the overall immunization coverage was high. MDH is in the process of completing a third comprehensive retrospective survey of children currently in kindergarten across the state.

Kindergarten surveys have been a very important source of local immunization data in Minnesota; however, they are limited because they represent coverage levels that are at least three years old. More current statewide data are available from the CDC. The CDC provides state-specific immunization level estimates through its National Immunization Survey (NIS). For 2000, the NIS estimated that 86.3% ± 4.5% of children between the ages of 19 and 35 months in Minnesota had received their primary series of baby shots (4 DTaP, 3 polio, 1 MMR, 3 Hib). When the hepatitis B vaccination was added, 82.4% ± 4.9% of children 19 to 35 months of age were up-to-date. Minnesota ranked second and third, respectively, in the nation with these rates.6

Immunization Registries

Immunization registry activity in Minnesota continues to focus on a statewide system of regional registries. These regional registries are identified in Figure 2. Historically, the decentralized registry approach was used to build upon the strengths of local relationships and to tailor systems to unique local and regional needs. At the same time, the statewide oversight provides consistency for registry standards and policies. This structure allows for sharing of regional and state strengths, implementing best practices, and maintaining cost-effectiveness. Most important, end users, such as local health agencies, managed care orgaizations, and individual clinics, remain the focal point of the system, and the essential elements of privacy and security are maintained.

Regional and state planning has led to the testing of a Web-based registry application that will be implemented in 2002. This system will be available statewide, accessible to authorized providers, and requires only an Internet connection and Web browser. The immunization registry application was originally developed by the State of Wisconsin and is being adapted for use in Minnesota. This results in some cost sharing as well as standardization for those health care systems with clinics in both states. More information on registries in Minnesota can be found at www.health.state. mn.us/divs/dpc/adps/registry/tools.htm.

Immunization Practices Improvement Project

The MDH has developed a new initiative as part of its Immunization and Minnesota Vaccines for Children (MnVFC) program. Through clinic visits, the Immunization Practice Improvement (IPI) initiative will assess and promote best practices related to immunizations. State and local health agency staff members have been trained to go into private and public clinics and survey immunization-related aspects of the practice, including vaccine storage and handling, documentation practices, vaccine administration procedures, and the clinics’ resources and educational needs. Clinical assessment software that allows clinics to determine immunization rates for their pediatric patients will be offered with the IPI visit. The goal of the initiative is to visit all clinics and continue visits on an ongoing basis. Initially 134 clinics have been randomly selected for visits; providers will be contacted by their local health agency or MDH and invited to take advantage of this opportunity for assessment and feedback. Providers who are not contacted but are interested in having an IPI visit should call the Minnesota Immunization Hotline at 800/657-3970 or 612/676-5100. 

The authors are with the Immunization, Tuberculosis, and International Health (ITIH) section of the Minnesota Department of Health. Lynn Bahta is supervisor of the ITIH’s Clinical Unit, Margaret Roddy is an epidemiologist and assistant section manager, and Diane Peterson is the supervisor of the ITIH’s Immunization Communications Unit. 

References

1. CDC. Shortage of tetanus and diphtheria toxoids. MMWR Morb Mortal Wkly Rep. 2000;49:1029-30.

2. CDC. Notice to readers: update on the supply of tetanus and diphtheria toxoids and of diphtheria and tetanus toxoids and acellular pertussis vaccine. MMWR Morb Mortal Wkly Rep. 2001;50:189-90.

3. CDC. Notice to readers: updated recommendations on the use of pneumococcal conjugate vaccine in a setting of vaccine shortage. MMWR Morb Mortal Wkly Rep. 2001;50:1140-2.

4. Minn Stat§ 121A.15, subd 12. (2001)

5. Ehresmann K, White K, Hedberg C, et al. A statewide survey of immunization rates in Minnesota school-age children: implications for targeted assessment and prevention strategies. Pediatr Infect Dis J. 1998;17:711-6.

6. CDC. National, state, and urban area vaccination coverage levels among children aged 19-35 months—United States, 2000. MMWR Morb Mortal Wkly Rep. 2001;50:637-41.