A new era opens for adolescent vaccines
Three new vaccines recommended for adolescents have hit the market this year. In January, the FDA approved a vaccine for meningococcal disease. Menactra, a polysaccharide conjugate vaccine (MCV4) developed by Sanofi Pasteur, is protective against four serogroups of Neisseria meningitidis. In May, the first vaccine to reinforce pertussis immunity, Boostrix (developed by GlaxoSmithKline), was approved, followed by a second vaccine, Adacel (from Sanofi Pasteur), in June.
The most common cause of bacterial meningitis is N. meningitidis. Infants have the highest prevalence rates, but adolescents and young adults have the highest morbidity and mortality rates. Pertussis rates have been on the rise in all age groups but especially in younger children, with most deaths occurring in infants younger than 6 months old.
Why we need the new vaccines
The previously licensed meningitis vaccine did not provide a T-cell memory response whereas the MCV4 does. Consequently, it provides longer-lasting immunity. MCV4 also decreases nasopharyngeal carriage and induces herd immunity. These are strong prevention properties the older vaccine lacked.
Pertussis immunity decreases after 5-10 years, leaving children aged 10-15 years with less protection. This is one reason infants are contracting pertussis from others, usually older family members or caregivers.1 Reducing the incidence in these older ages will decrease the chance of infants getting pertussis.
Epidemiology: Although the incidence of invasive meningococcal disease has remained fairly stable in the United States for the past few decades, it does fluctuate on a regular basis from around 1,400 to 2,800 cases annually. Mortality rates vary from 10% to 14% with morbidity rates at 11%-19%. Some of the long-term effects of the disease are neurologic damage, seizures, deafness, and limb amputation. Of the 12 known serogroups of N. meningitidis, C, Y, and W-135 cause about 60% of all disease in the United States. The MCV4 provides protection against these serogroups as well as group A. The remaining cases are caused by serogroup B.2 Unfortunately, serogroup B is the cause of most meningococcal infections in infants, and currently, there is no vaccine effective against this serogroup.
American Academy of Pediatrics (AAP)/CDC recommendations: Menactra has been licensed for use in patients aged 11-55 years. The CDC's Advisory Committee on Immunization Practices (ACIP) has recommended this vaccine as part of the routine immunization schedule.3 Because of limited initial availability, immunization will begin with two cohorts: (1) 11- to 12-year-olds, and (2) 15-year-olds or those entering high school, whichever is first at the well-child visit. Other groups for which the vaccine is currently recommended are students entering college and planning to live in dormitories, persons at increased risk of infectious meningococcal disease, patients with terminal complement deficiency or functional or actual asplenia, immunocompromised patients, and military recruits.
Epidemiology: Pertussis is the only communicable disease on the rise for which a vaccine is available. In 2004, there were 63% more cases of pertussis compared with 2003. Of these cases, 36% were in children younger than 4 years of age. This age group is also the most likely to be underimmunized. Pertussis has a mortality rate of about 80% in infants younger than 6 months of age. Although the disease decreases in severity as the child ages, the morbidity can still be significant. Effects can include pneumonia, rib fractures, weight loss, and secondary upper respiratory infections. In addition, more than 70% of adolescents diagnosed with pertussis report missing 5-10 days of school.
AAP/CDC recommendations: The new pertussis booster is recommended to replace the current Td booster given to 11- to 12-year-olds during well-child visits. It is also recommended that an adolescent wait five years between Td vaccine and new Tdap vaccine unless the individual is at increased risk. The meningitis and Tdap vaccines can be given at the same visit. For more information about the new vaccines, see Table 1.
Incorporating these vaccines into routine adolescent well-child visits
Getting adolescents to come in to a health-care provider's office for a well-child visit or health promotion and prevention visit has always been a challenge. Fewer than 20% of kids aged 16-18 years make such visits. Adolescents, as a group, are usually healthy and resistant to the thought of undressing, having their changing bodies examined, and answering embarrassing questions. However, it is during adolescence that many potentially harmful behaviors begin. The AAP has long endorsed annual visits for adolescents as an opportunity to discuss risk-taking and behaviors that may have health consequences. The reality is that the AAP recommendation has not been enough to get teenagers into the office. In infancy and the early years of life, well-child care is tied to routine immunizations, and if asked, most parents would probably say that they take their child to the health-care provider's office for “shots,” not for the anticipatory guidance we provide. Maybe this strategy will work with adolescents, and we can provide anticipatory guidance on the side once we have the children in our offices.
Some states require physical examinations for entrance into fifth grade and high school. This has been an effective strategy for exposing the child in early and mid adolescence to a health-care provider and subsequent health counseling. In such states, it will be much easier to implement the new routine vaccinations than in states where such requirements are not already in place. Opportunistic immunization can take place during most office visits, especially those for minor illness evaluations.
It has been recommended that the number of locales where vaccines can be administered should be expanded to include schools and pharmacies. While this may initially sound like a good idea, it negates the goal of a medical home base and a supportive relationship with a health-care provider.4 Moreover, parental consent is required for all vaccines in 43 states and the District of Columbia, further hampering the ability to offer vaccines in nontraditional venues.5 Looking to the future, several promising vaccines for adolescents are in development. One that is on the near horizon is for protection against the human papillomavirus (sidebar). Also in the future are additional vaccines for the prevention of herpes simplex virus, chlamydia, cytomegalovirus, streptococcus, and HIV.
Ms. Waldrop is clinical associate professor at the University of North Carolina Schools of Nursing and Medicine in Chapel Hill and a contributing editor to The Clinical Advisor.
1. Bisgard KM, Pascual FB, Ehresmann KR, et al. Infant pertussis: who was the source? Pediatr Infect Dis J. 2004;23:985-989.
2. Rosenstein NE, Perkins BA, Stephens DS, et al. The changing epidemiology of meningococcal disease in the United States, 1992-1996. J Infect Dis. 1999;
3. Biluhka OO, Rosenstein N, National Center for Infectious Diseases, Centers for Disease Control and Prevention (CDC). Prevention and control of meningococcal disease. Recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR Recomm Rep. 2005;54(RR-7):1-21.
4. Rusk J. Strengthening adolescent vaccine delivery will be a big task. Infect Dis Child. Available at www.idinchildren.com/200507/vaccine.asp. Accessed September 12, 2005.
5. Gordon TE, Zook EG, Averhoff FM, Williams WW. Consent for adolescent vaccination: issues and current practices. J Sch Health. 1997;67:259-264.