In the early 1990s, programs to promote immunization for infants and young children were established and eventually resulted in significantly improved immunization rates for these groups. However, adolescent immunization rates continued to lag. By 1996, the Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics (AAP), the American Academy of Family Physicians (AAFP), and the American Medical Association (AMA) jointly published guidelines that were meant to improve these by focusing on immunizing adolescents at a routine health supervision visit at ages 11 to 12 years.1 In addition, during the past several years, more states have incorporated immunization requirements for entry into the 7th grade into law.2 Together, these initiatives have begun to bear fruit, resulting in increased adolescent immunization rates.
The focus on adolescents 11 to 12 years old occurred for several reasons. Many states already required physical examinations for children entering middle school, and medical providers could easily immunize them at those visits. In addition, younger adolescents tend to be seen more regularly than older adolescents for health supervision.3 Hence, there are more opportunities to immunize younger adolescents. Additionally, with immunization at 11 to 12 years of age instead of later in adolescence, earlier immunologic protection is afforded.4
SPECIFIC IMMUNIZATIOMS RECOMMENDED FOR ADOLESCENTS
Hepatitis B Vaccine
Approximately 70% of hepatitis B infections occur in late adolescence and early adult life.5 Hepatitis B is primarily transmitted by sexual contact, parenteral drug use, home contact with a carrier of hepatitis B, or occupational exposure.1
Although health supervision visits at 11 to 12 years of age are ideal times to immunize adolescents, the ACIP also recommends that older adolescents receive hepatitis B vaccine if they were not previously immunized.6 This is based on an estimated 160,000 additional hepatitis B infections, 10,000 additional chronic hepatitis B infections, and 1,400 additional deaths that would eventually be expected to occur if current adolescents 16 to 18 years old were not immunized.7 A new two-dose immunization schedule for adolescents has recently been introduced. It is likely to result in higher rates of completion of the hepatitis B series than have been demonstrated with the three-dose immunization schedule.
The Second Dose of Measles-Mumps-Rubella (MMR) Vaccine
If not previously administered, the second dose of MMR vaccine should be given by 11 to 12 years of age. This recommendation for a second dose was first made in 1989, at the time of several measles outbreaks that primarily affected adolescents and young adults. The resurgence of measles from 1989 to 1991 resulted in many deaths and cost the United States approximately $100 million.8 Primary vaccine failure was seen as the principal contributing factor in the resurgence of measles and was the driving force for reimmunization.1
Most states now require two MMR immunizations before children first enter school. The routine health supervision visit at ages 11 to 12 years is an ideal time to immunize children who did not receive the second dose of MMR previously. Pregnant adolescents and adolescents who anticipate becoming pregnant within 3 months should not be immunized.1
Diphtheiia and Tetanus Toxoids and Acellular Pertussis Vaccine
Because immunity to tetanus decreases over rime, a booster oí tetanus toxoid is generally recommended every 10 years. However, studies have shown that immunity to tetanus varies with age.9 A significant decrease in the protective levels of tetanus antitoxin has been noted 6 to 10 years after children receive their boosters at ages 4 to 6 years.10 Therefore, providing the tetanus and diphtheria toxoids, adult type (Td) immunization at ages 11 to 12 years instead of ages 14 to 16 years should result in both better compliance and reduced susceptibility to tetanus.1
Diphtheria is extremely rare in the United States. However, it continues to be seen in certain areas of the world, particularly in the nations that formerly comprised the Soviet Union. In this age of international travel, it is especially important to maintain high levels of immunity to diphtheria.1
Thus, the Td booster should ideally be given at ages 11 to 12 years unless one had been given since the booster at ages 4 to 6 years. The next Td booster should be given 10 years after one administered during adolescence.1
Varicella Vaccine for Susceptible Adolescents
Varicella infection often leads to considerable morbidity when susceptible adults or adolescents 15 years or older contract the virus. Death rates associated with varicella are also considerably higher in these age groups.1 Hence, it is particularly important that adolescents 11 to 12 years old who previously neither were immunized against varicella nor had varicella receive the immunization. Before the age of 13 years, a single dose of the vaccine is sufficient. However, from 13 years of age on, two doses 4 to 8 weeks apart are recommended. Physicians may choose to obtain varicella titers prior to immunizing if it is unclear whether a patient has had varicella. Immunocompromised adolescents, pregnant adolescents, and adolescents who are considering becoming pregnant within 1 month should not receive the vaccine.11
IMMUNIZATIONS SUGGESTED FOR SELECTED POPULATIONS OF ADOLESCENTS
Hepatitis A Vaccine
Hepatitis A is generally transmitted from person to person, with the highest rates of disease between ages 5 and 14 years.1 For several years, hepatitis A vaccine has been routinely recommended for children residing in certain states in the United States. In 2001, that recommendation was extended to include adolescents through age 18 years and individuals in certain high-risk groups (eg, individuals traveling to countries where hepatitis A is moderately or highly endemic, men who have sex with men, users of illicit drugs, individuals with clotting-factor disorders, individuals working with nonhuman primates, and individuals with chronic liver disease).12
Influenza vaccine should be administered yearly to individuals (including children and adolescents) who have chronic pulmonary or cardiovascular conditions; reside in chroniccare facilities with individuals having chronic illnesses; have diabetes mellitus, renal dysfunction, hemoglobinopathies, or immunosuppressive disorders; or receive long-term aspirin therapy.1
During a 1-year period from 1998 to 1999, 90 cases of meningococcal disease were reported among U.S. college students. Although the overall rate of meningococcal disease was lower among college students than among the general population ages 18 to 23 years who were not enrolled in college, rates were higher among specific subgroups of college students. The highest rates were found among freshmen living in dormitories. In 2000, the ACIP recommended that providers of care to incoming and current college freshmen (in particular, freshman who plan to or already live in residence halls) should, during routine medical care, inform the students and their parents about meningococcal disease and the benefits of immunization. Colleges were advised to also inform them about meningococcal disease and the availability of the vaccine.13 The movement to immunize college students against meningococcal disease is rapidly gaining momentum.
Adolescents with anatomic or functional asplenia, nephrotic syndrome, leaks of cerebrospinal fluid, or conditions associated with immunosuppression should receive 23-valent pneumococcal polysaccharide vaccine. Revaccination is recommended if more than 5 years have elapsed since administration of the first dose of the vaccine.1
The recently licensed 7-valent pneumococcal conjugate vaccine provides coverage against 50% to 60% of invasive pneumococcal isolates in high-risk older children, adolescents, and adults, compared with more favorable coverage rates of 80% to 90% for 23-valent pneumococcal polysaccharide vaccine. Hence, 23-valent pneumococcal polysaccharide vaccine should not be replaced with 7-valent pneumococcal conjugate vaccine for use among high-risk individuals in these age groups. However, because pneumococcal conjugate vaccine is immunogenic for most high-risk adolescents and may provide some additional protection, its administration is not contraindicated for adolescents who have previously received pneumococcal polysaccharide vaccine.13
STRATEGIES FOR IMMUNIZING ADOLESCENTS
Middle School Immunization Requirements
The establishment of middle school immunization requirements is probably the most effective strategy for ensuring that adolescents are immunized. During the past several years, more states have instituted such requirements, particularly for hepatitis B. Twenty states and the District of Columbia have hepatitis B immunization requirements for middle school students, whereas a smaller number also require that these children be immunized against varicella or provide documentation of having had varicella.2
During the past decade, several initiatives were undertaken to promote school-based immunizations, primarily for middle school students. The results of these initiatives have been mixed.14 In general, the more successful school-based efforts provided extensive education to students and parents about the importance of immunizations.
Minimizing Missed Opportunities to Immunize
Efforts to encourage providers of medical care to minimize missed opportunities to immunize have the potential to raise adolescent immunization rates. Such efforts may include standing orders for immunization, provider incentives, benchmarking, and provider education.15
Tracking. Reminders, and Recall
Extensive regional and statewide immunization registries have been established during the past several years. Most of these immunization registries include immunization information on infants and young children only. Expanding registries to include adolescents should provide valuable information that would greatly assist adolescent immunization.
The tracking of immunizations (eg, by the use of immunization registries), combined with reminder and recall systems, has been highly effective in improving immunization rates among both preschool children and adults.15 It is likely that these methods will also be effective when used in an organized way to promote adolescent immunization.
As new immunizations become available to prevent a number of medical conditions for which adolescents and young adults are at particular risk (eg, chlamydia, herpes simplex, and human immunodeficiency virus infections), it will be especially important to have effective adolescent immunization strategies. Toward that end, we must continue to integrate and build on the immunization strategies that have been successful in advancing immunization efforts for adolescents and others.
1. Centers for Disease Control and Prevention. Immunization of adolescents: recommendations of the Advisory Committee on Immunization Practices, the American Academy of Pediatrics, the American Academy of Family Physicians, and the American Medical Association. MMWR. 1996;45(RR13):1-16.
2. Immunization Action Coalition. What's your state doing? State childhood vaccination rates and school mandates. Needle Tips. 2000;10:14.
3. Nelson C. Office visits by adolescents. In: Advance Data From Vital and Health Statistics, no. 196. Hyattsville, MD: National Center for Health Statistics; 1991:1-6.
4. Averhoff FM, Williams WW, Hadler SC. Immunization of adolescents. Am Fam Physician. 1997;55:159-167.
5. Margolis HS, Coleman PJ, Brown RE, Mast EE, Sheingold SH, Arevalo JA. Prevention of hepatitis B virus transmission by immunization: an economic analysis of current recommendations. JAMA. 1995;274:1201-1208.
6. Centers for Disease Control and Prevention. Update: recommendations to prevent hepatitis B virus transmission: United States. MMWR. 1999;48:33-34.
7. Smith NM, Averhoff FM. The effects of expanding hepatitis B vaccination recommendations for all children and adolescents. Presented at the Pediatric Academic Societies Annual Meeting; May 1-5, 1998; New Orleans, LA.
8. National Committee for Quality Assurance. The State of Managed Care Quality: 2000. Washington, DC: National Committee for Quality Assurance; 2000:1-71.
9. Gergen PJ, McQuillan GM, Kiely M, Ezzati-Rice TM, Sutter RW, Virella G. A population-based serologic survey of immunity to tetanus in the United States. N Engl J Med. 1995;332:761-766.
10. Centers for Disease Control and Prevention. Prevention of varicella: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR. 1996;45(RR11):1-25.
11. American Academy of Pediatrics. Varicella-zoster infections. In: Peter G, ed. 2997 Red Book: Report of the Committee on Infectious Diseases, 24th ed. Elk Grove Village, IL: American Academy of Pediatrics; 1997:573-585.
12. Centers for Disease Control and Prevention. Recommended childhood immunization schedule: United States, 2001. MMWR. 2001;50:7-10, 19.
13. Centers for Disease Control and Prevention. Meningococcal disease and college students: recommendations of the Advisory Committee on Immunization Practices. MMWR. 2000;49(RR07): 11-20.
14. Unti L, Woodruff BA. A Review of Adolescent School-Based Hepatitis B Immunization Projects: A Report Prepared for the Centers for Disease Control and Prei'ention, Hepatitis Branch. Washington, DC: U.S. Department of Health and Human Services, Public Health Service; 1996.
15. Centers for Disease Control and Prevention. Vaccine-preventable diseases: improving vaccination coverage in children, adolescents, and adults: a report on recommendations from the Task Force on Community Preventive Services. MMWR. 1999;48(RR08):M5.