Minnesota Medicine

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

Vaccinating Adults for Vaccine-Preventable Diseases

By Diane C. Peterson, Lynn Bahta, R.N., and Kristen Ehresmann, R.N., M.P.H.

Most vaccine-preventable morbidity and mortality in the United States occur in adults, primarily from complications associated with influenza, pneumococcal disease, and hepatitis B infections. Each year, influenza will cause an estimated 20,000 deaths and more than 100,000 hospitalizations; severe pneumococcal disease will occur in more than 45,000 people and result in 6,000 deaths; and the hepatitis B virus will infect approximately 80,000 people, mostly adolescents and young adults.1,2,3,4 Yet, most of the attention over the last decade has been focused on children’s vaccination needs. It is time to give equal consideration to adult vaccination.

Influenza

Unlike other vaccines, influenza vaccine has to be formulated and administered annually to provide protection against the viruses predicted to be prevalent during the influenza season. The course of this vaccine production process is determined by many factors, including the timing of the selection of the vaccine virus, the number of new strains selected, the ability of each virus to grow in culture, the amount of virus that is produced, and the ability of manufacturers to adhere to the good manufacturing practices (GMP) of the FDA. Delays or problems in any part of the process may cause disruptions in vaccine distribution and availability, which has been the case the past two years.

Problems with both production of the vaccine and the timing of its distribution contributed to the significant delays experienced in the fall of 2000. In 2001, vaccine production went smoothly, but vaccine lots were not released in a timely fashion, especially those lots manufactured by Wyeth Lederle. Unfortunately, those who ordered solely from Wyeth did not begin to receive vaccine until early November, which is historically the time that most vaccination activities are winding down.

Last year, and again this past fall, the Minnesota Department of Health (MDH) developed and distributed a vaccination plan to help communities prepare for delays in flu vaccine distribution for the 2000 and 2001 flu seasons. The MDH has been working to ensure that all providers of influenza vaccine are committed to vaccinating the high-risk patients first and low-risk 

patients later in the season, once supply is adequate. Although the Minnesota Coalition on Adult Immunization, the MDH Immunization Practices Task Force, and all the major health plans have endorsed this plan, it is voluntary. The purchase, distribution, and administration of the flu vaccine are mainly private-sector activities and are free-market driven. This limits the ability of state or local government to intervene. 

Flu vaccine demand is seasonal. People think, “Now that it’s October, I need to put on the storm windows, check my football tickets, and get my flu shot.” The challenge for providers is to convince patients that it’s never too late to get vaccinated—even if it’s December or January and even if and as long as flu is circulating in the community. The best way to convey that message is to continue to offer flu vaccination to patients throughout the winter season.

Despite the challenges of influenza vaccine distribution and administration, rates of influenza vaccination have increased in Minnesota and nationally over the past decade. These successes are tempered by disparities in immunization coverage levels for American Indians and populations of color in Minnesota. Efforts should be made to reach all patient populations with culturally appropriate vaccination messages.

Pneumococcal Disease

Vaccination rates with pneumococcal polysaccharide vaccine (PPV) have risen slowly but steadily over the past several years. Rates among persons older than 65 have increased from 30% in 1993 to 65% in 2000. However, only half (51%) of all adults with diabetes have been vaccinated. A recent survey of Minnesota seniors found that respondents were significantly influenced by whether or not their physician offered them the PPV. Therefore, providers’ practices are critical targets for improving PPV coverage. Efforts to educate patients about PPV and to address misconceptions, such as those about the vaccine’s safety and efficacy, and about Medicare coverage for the vaccine also may improve vaccination levels. 5

Unlike patients needing flu vaccination, patients who need the PPV should be vaccinated throughout the year. The MDH, working with the state’s Medicare quality improvement organization, developed information packets to assist clinics in improving PPV coverage levels. Kits for clinics, hospitals, and long-term care facilities are available through Stratis Health’s Web site (www.stratishealth.org) or by calling 952/853-8543. The National Vaccine Advisory Committee has issued recommendations that suggest using nontraditional settings such as pharmacies, senior centers, churches, and the work place to encourage vaccination of at-risk individuals. The Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention recommends issuing standing orders for both pneumococcal and influenza vaccination, particularly in long-term care facilities. 6,7 

Hepatitis B

Hepatitis B vaccine was first introduced in 1981 and targeted to populations at highest risk for the infection. After a decade without appreciable impact on rates of infection, the ACIP issued recommendations for routine vaccination of all infants as a national strategy to eliminate hepatitis B disease. In 1995, since hepatitis B occurs mainly in young adults, the recommendations were expanded to include routine vaccination of all adolescents and Asian/Pacific Islander immigrant children.8 

In Minnesota, hepatitis B vaccination has been recommended for both infants and adolescents since 1993. State law now requires documentation of hepatitis B vaccination (or a legal exemption) for children entering kindergarten and 7th grade. The vaccine is also recommended for all adults who are at increased risk of infection. Due to the continued high rate of sexually transmitted hepatitis B infections in Minnesota, health care providers are encouraged to discuss testing and immunization with at-risk patients.9

Tetanus and Diphtheria

Eight cases of tetanus have occurred in Minnesota in the past 7 years. Tetanus is most likely to occur in unvaccinated or inadequately vaccinated persons. A recent serologic survey for tetanus immunity revealed that only about a third of people 70 years of age and older were immune. It confirmed that individuals up to age 39 were well protected (about 80% had evidence of immunity) and that the prevalence of immunity dropped sharply with increasing age.10

A severe tetanus-diphtheria (Td) vaccine shortage has created an interruption in routine booster vaccination activities (see “Childhood Vaccinations—What’s New?” p. 33). This means that when adults see their physician, they might not get the booster dose the provider otherwise would have suggested. Physicians and other medical providers should consider a callback system that can recall those adults whose booster doses were deferred, once the vaccine is again readily available.11

Hepatitis A

Hepatitis A vaccination is not a routinely recommended vaccine for adults. Periodic outbreaks do occur throughout Minnesota and have accounted for up to 40% of the annual cases of hepatitis A. In the past few years, however, about a third of acute hepatitis A cases have occurred in risk groups for whom hepatitis A vaccination is recommended.9, 12, 13 

On average, about 20% of acute hepatitis A disease in Minnesota occurs in persons who have a recent history of foreign travel, including trips to Mexico and the Caribbean. 9, 12, 13 People traveling to developing countries frequently consult their physicians and will ask for vaccinations, including a hepatitis A vaccination. However, travelers to the Caribbean or Mexico, both of which have moderate rates of hepatitis A disease, tend to request prophylactic antibiotics rather than vaccinations. Providers can take advantage of the patient’s interest in preventive health care by recommending hepatitis A vaccination and/or immune globulin if travel is imminent within 4 weeks. Other populations known to be at risk for hepatitis A include contacts of persons diagnosed with acute hepatitis A, men who have sex with men, IV drug users, and day care workers. Because one-third of Minnesota cases have no identified risk factor, people older than 2 years of age who wish to protect themselves from hepatitis A disease should be vaccinated. Knowledge of the risk factors for hepatitis A disease in adults will prompt health care providers to take preventive action by immunizing at-risk adults.13 

The authors are with the Immunization, Tuberculosis, and International Health (ITIH) section of the Minnesota Department of Health. Diane Peterson is the supervisor of the Immunization Communications Unit, Lynn Bahta is supervisor of the Clinical Unit, and Kristen Ehresmann is an epidemiologist and chief of the section.

References 

1. CDC. Prevention of pneumococcal disease: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep. 1997;46(RR-8):1-24.

2. CDC. Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Morb Mortal Wkly Rep. 2001;50(RR-4):1-46.

3. Feikin DR, Schuchat A, Kolczak M, et al. Mortality from invasive pnuemococcal pneumonia in the era of antibiotic resistance, 1995 - 1997. Am J Public Health. 2000;90(2):223-9.

4. CDC. Protection against viral hepatitis: recommendations of the Immunization Practices Advisory Committee (ACIP). MMWR Morb Mortal Wkly Rep. 1990;39:5-22.

5. Ehresmann K, Ramesh A, Como-Sabetti K, Peterson D, Whitney C, Moore K. Factors associated with self-reported pneumococcal immunization among adults 65 years of age or older in the Minneapolis-St. Paul metropolitan area. Prev Med. 2001;32:409-415. 

6. CDC. Adult immunization programs in nontraditional settings: quality standards and guidance for program evaluation. MMWR Morb Mortal Wkly Rep. 2000;49(RR-01):1-13.

7. CDC. Use of standing orders programs to increase adult vaccination rates. MMWR Morb Mortal Wkly Rep. 2000;49(RR-01):15-26.

8. CDC. Hepatitis B virus: a comprehensive strategy for eliminating transmission in the United States through universal childhood vaccination. MMWR Morb Mortal Wkly Rep. 1991;40(RR-13):1-19.

9. Minn. Dept. of Health. Disease Control Newsletter. 2001;29:34-5.

10. CDC. Tetanus Surveillance United States, 1995-1997. MMWR Morb Mortal Wkly Rep. 1998;47(SS-2):1-47.

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

12. Minn. Dept of Health. Disease Control Newsletter 1999;27:30.

13. Minn. Dept. of Health. Disease Control Newsletter 2000;28:40-1.