Costs: The VFC program has been important in providing vaccines to children who are Alaskan Natives, American Indian Natives, Medicaid-eligible, or without insurance coverage. However, VFC and 317 other programs face funding challenges and at times have had insufficient monetary support to cover all recommended vaccines. In their study, Smith and colleagues found that immunization rates among VFC-eligible children who received all recommended vaccines from their medical home were as likely to be up to date as non-VFC-eligible children who had a medical home.7 VFC-eligible children who lacked a medical home or who had incomplete insurance coverage for vaccines were less likely to be adequately immunized.
In order to provide all the recommended vaccines, a health-care practice must make a significant financial investment in supplies and in knowledgeable personnel who can administer the injections. Some providers are unable to recover their costs. Providers can also incur financial losses if privately purchased vaccines are lost as a result of waste or because of refrigerator or other storage malfunction.
Immunization schedule: Another systems barrier is the complexity of the immunization schedule. Over the past 25 years, the number of childhood vaccines has more than doubled. In the early 1980s, there were 11 recommended childhood vaccines to prevent seven diseases.8 In 2007, the number of diseases preventable by childhood vaccines had increased to 16. Children may receive as many as 24 vaccines during the first two years of life. The complexity of the immunization schedule has posed challenges for both families and providers.
Although a number of vaccines are required by schools and day-care facilities, there are other vaccines that are recommended but not required. Oftentimes, newer vaccines that are recommended but not required are unavailable through the VFC program and may not be covered by individual insurance plans. Some insurance companies were initially reluctant to reimburse for the Tdap vaccine but would reimburse for the tetanus and diphtheria (Td) vaccine, leaving many adults and adolescents at risk of contracting pertussis.
Vaccine recommendations in the United States are made by the Advisory Committee on Immunization Practices (ACIP). This group includes representatives from the American Academy of Pediatrics and the American Academy of Family Physicians. ACIP provides recommendations regarding vaccines and the timing of their administration to the CDC, which issues immunization schedules for children as well as adults each year. The infant immunization schedule was developed so that children could receive most of the required as well as recommended vaccines by age 2 years. A single harmonized schedule of recommended childhood vaccines allows for consistency across different medical disciplines. The schedule provides age ranges (0-6 years, 7-18 years, adults) at which vaccines can be administered as well as a catch-up schedule to get children who have fallen behind to receive all vaccines by age 2 years. NPs and PAs can refer to the CDC Web site for the most current vaccine recommendations for each age group in their practice. Despite recommendations from the ACIP and the CDC, some health-care providers do not adhere to the schedule because of personal or philosophical differences.
Provider barriers
Support from the health-care provider and clinic staff is an important predictor of childhood immunizations.9 This support may take the form of educating the family on the importance of immunizations and alleviating fears about potential benefits and risks. Because the immunization schedule is so complex, office staff members sometimes have difficulty interpreting the vaccine record of an individual patient. This can lead to vaccines being overlooked or missed or to the administration of invalid doses.
Missed opportunities: One of the most significant provider-related barriers impacting immunization rates is missed opportunities,10 i.e., those health-care encounters in which a child failed to receive a required immunization for which he was eligible. Missed opportunities include visits to the clinic by the family for a sick or urgent-care appointment; few illnesses prevent a child from receiving a vaccine. In addition, children or adults accompanying another child or family member to an appointment could receive vaccines if the determination is made that they are missing recommended vaccine doses.
Missed opportunities present a significant barrier to adequate immunization by the age of 2 years. In a study led by Bardenheier, the majority of children who were not up to date on vaccines were behind because of missed opportunities. The authors found that underimmunization at 3 months of age was a strong predictor for remaining underimmunized by age 2 years.11 In another study, delayed receipt of the vaccines due at 2 months was a strong risk factor for lack of age-appropriate vaccines at age 2 years.12
The well-child exams done when children are 9 months old and 18 months old are times when those who are behind in their vaccines could be brought up to date. In attempting to identify reasons for incomplete immunizations in 2-year-olds, one study found that 46% of such patients had failed to receive the fourth dose of the diphtheria, pertussis, tetanus (DPT) vaccine at the 18-month visit.13 Therefore, using the 18-month well-child examination as an opportunity for providing vaccines can significantly reduce the number of children incompletely vaccinated at 2 years of age. In addition, asking about immunization status at each and every office visit will ensure that children and adults have received all needed vaccines.
Combination vaccines are useful for administering multiple vaccines with a single injection. This approach also reduces the pain associated with receiving several injections at the same visit. Combination vaccines have been in use for years. Vaccines such as the measles, mumps, rubella (MMR) and the DTap vaccines are familiar to clinicians. A number of other vaccines are available in combination, including one for hepatitis A and hepatitis B and a vaccine that contains MMR and varicella.