Addressing immunization barriers, benefits, and risks

Journal of Family Practice, Feb, 2007 by Sanford R. Kimmel, Ilene Timko Burns, Robert M. Wolfe, Richard Kent Zimmerman

Vaccines have been highly effective in eliminating or significantly decreasing the occurrence of many once-common diseases. Barriers to immunization are a significant factor in the rising incidence rates of some vaccine-preventable diseases. Cost, reduced accessibility to immunizations, increasingly complex childhood and adolescent/adult immunization schedules, and increasing focus on the potential adverse effects of vaccines all contribute to difficulty in meeting the 2010 immunization goals. Physicians must not only be knowledgeable about vaccines but they must incorporate systems in their offices to record, remind, and recall patients for vaccinations. They must also clearly communicate vaccine benefits and risks while understanding those factors that affect an individual's acceptance and perception of those benefits and risks.

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Vaccines have almost eliminated or significantly reduced the incidence of many diseases, but tens of thousands of children and adults in the United States continue to develop vaccine-preventable diseases. Reported cases of pertussis have increased from a low of 1010 cases in 1976 (1) to 25,827 in 2004, (2) with the majority of these cases occurring in adolescents and adults. Potential reasons for this include genetic changes in Bordetella pertussis (which make vaccines less effective), decreased potency of pertussis vaccines, greater awareness of pertussis, and improved diagnostic tests. (3) However, many of these cases are believed to be caused by waning immunity or inadequate immunization. In 2005, only 76.1% of US children aged 19 to 35 months had received all of the recommended doses of DTaP, Hib, hepatitis B, MMR, polio, and varicella vaccines, although rates of those who received most individual vaccines were higher. (4) A Healthy People 2010 goal is to immunize 90% of young children and adolescents with age-appropriate vaccines. (5)

Barriers to immunization are grouped as systems barriers (eg, those involving the organization of the health care system and economics), health care provider barriers (eg, inadequate clinician knowledge about vaccines and contraindications to their use), and parent or patient barriers (eg, fear of immunization-related adverse events). (6) These barriers affect immunization rates and increase the burden of preventable disease in our society.

Systems Barriers to Immunization

Factors affecting the supply and distribution of vaccines are among the most noticeable systems barriers. The supply of influenza, conjugate pneumococcal, and, most recently, tetravalent conjugate meningococcal (MCV4) vaccines have been inadequate due to a lack of manufacturing capacity. (7) A misdistribution of vaccines has also occurred. Uninsured and Medicaid-insured children may qualify to receive vaccines through the Vaccines for Children program (VFC), but VFC does not provide funding to reimburse providers for the costs of administering those vaccines. Uninsured adults represent another major systems problem.

Provider Barriers to Immunization

Providers may lack knowledge about the indications for and contraindications to immunization. Expanded uses for current vaccines such as hepatitis A vaccine for children aged 12 months or older and new vaccines against rotavirus and zoster make it difficult for health care providers to stay current with immunization schedules. A study of California practices found that knowledge deficits regarding immunization schedules, vaccine contraindications, and vaccine side effects were present among physicians and nonphysician office staff. (8)

One early study indicated that almost one half of nurses (as reported by physicians) were resistant to giving children 3 or more injections and that parents and physicians were also uncomfortable about this. (9) However, a later study at an inner-city pediatric clinic indicated that parents overwhelmingly complied with physicians' recommendations for immunizations. (10) Thus, the attitude the physician transmits to his or her staff about the importance of immunizations is crucial. Combination vaccines that decrease the number of shots administered at a single visit also enhance compliance.

Logistical barriers faced by health care providers include the cost of immunizations, vaccine storage or capacity, and lack of access to patients' prior immunization records. Vaccines with stringent storage requirements, such as varicella vaccine or live attenuated influenza vaccine, may present a challenge. Fragmentation of patient care makes it more likely that providers will not have complete immunization records for patients currently in their care. This can lead to incomplete immunization and overimmunization.

Missed visits and missed opportunities for immunization when necessary vaccines are not administered at a visit are also notable barriers to timely completion of immunization requirements. When health care providers have routinely assessed a patient's immunization status and notified patients and parents about vaccinations that were due (reminders) or overdue (recalls), immunization rates have improved. Reminder/recall systems can be time-consuming and cost-intensive, and they are used infrequently. (11) Greater use of electronic medical record systems should make reminder/recall systems more efficient.