*These minimum acceptable ages and intervals may not correspond with the optimal recommended ages and intervals for vaccination. See tables 3-5 in the ACIP's General Recommendations on Immunization and ACIP's "Recommended Childhood Immunization Schedule, United States, January-December 1998" for the current recommended routine and accelerated vaccination schedules.

†The total number of doses of diphtheria and tetanus toxoids should not exceed six each before the seventh birthday.

§The booster dose of Hib vaccine which is recommended following the primary vaccination series should be administered no earlier than 12 months of age and at least 2 months after the previous dose of Hib vaccine (Tables 3 and 4 of ACIP's General Recommendations on Immunization).

¶Sequential IPV/OPV, all-OPV, or all-IPV.

**For unvaccinated adults at increased risk of exposure to poliovirus with <3 months but >2 months available before protection is needed, three doses of IPV should be administered at least 1 month apart.

††If the third dose is given after the third birthday, the fourth (booster) dose is not needed.

§§Although the age for measles vaccination may be as young as 6 months in outbreak areas where cases are occurring in children <1 year of age, children initially vaccinated before the first birthday should be revaccinated at 12-15 months of age and an additional dose of vaccine should be administered at the time of school entry or according to local policy. Doses of MMR or other measles-containing vaccines should be separated by at least 1 month.

¶¶This final dose is recommended at least 4 months after the first dose and no earlier than 6 months of age. For children not vaccinated at birth, the recommended interval is first dose at elected date, second dose 1 month later, third dose 5 months after second dose.

Recommended Childhood Immunization Schedule
United States, January - December 2000

Vaccines¹ are listed under routinely recommended ages. Bars indicate range of recommended ages for immunization. Any dose not given at the recommended age should be given as a "catch-up" immunization at any subsequent visit when indicated and feasible. Ovals indicate vaccines to be given if previously recommended doses were missed or given earlier than the recommended minimum age.

¹ This schedule indicates the recommended ages for routine administration of currently licensed childhood vaccines as of 11/1/99. Additional vaccines may be licensed and recommended during the year. Licensed combination vaccines may be used whenever any components of the combination are indicated and its other components are not contraindicated. Providers should consult the manufacturers' package inserts for detailed recommendations.

² Infants born to HBsAg-negative mothers should receive the 1st dose of hepatitis B (Hep B) vaccine by age 2 months. The 2nd dose should be at least 1 month after the 1st dose. The 3rd dose should be administered at least 4 months after the 1st dose and at least 2 months after the 2nd dose, but not before 6 months of age for infants.

Infants born to HBsAg-positive mothers should receive hepatitis B vaccine and 0.5 mL hepatitis B immune globulin (HBIG) within 12 hours of birth at separate sites. The 2nd dose is recommended at 1 month of age and the 3rd dose at 6 months of age.

Infants born to mothers whose HBsAg status is unknown should receive hepatitis B vaccine within 12 hours of birth. Maternal blood should be drawn at the time of delivery to determine the mother's HBsAg status; if the HBsAg test is positive, the infant should receive HBIG as soon as possible (no later than 1 week of age).

All children and adolescents (through 18 years of age) who have not been immunized against hepatitis B may begin the series during any visit. Special efforts should be made to immunize children who were born in or whose parents were born in areas of the world with moderate or high endemicity of hepatitis B virus infection.

³ The 4th dose of DTaP (diphtheria and tetanus toxoids and acellular pertussis vaccine) may be administered as early as 12 months of age, provided 6 months have elapsed since the 3rd dose and the child is unlikely to return at age 15 to 18 months. Td (tetanus and diphtheria toxoids) is recommended at 11 to 12 years of age if at least 5 years have elapsed since the last dose of DTP, DTaP, or DT. Subsequent routine Td boosters are recommended every 10 years.

⁴ Three Haemophilus influenzae type b (Hib) conjugate vaccines are licensed for infant use. If PRP-OMP (PedvaxHIB or ComVax [Merck]) is administered at 2 and 4 months of age, a dose at 6 months is not required. Because clinical studies in infants have demonstrated that using some combination products may induce a lower immune response to the Hib vaccine component, DTaP/Hib combination products should not be used for primary immunization in infants at 2, 4, or 6 months of age unless FDA-approved for these ages.

⁵ To eliminate the risk of vaccine-associated paralytic polio (VAPP), an all-IPV schedule is now recommended for routine childhood polio vaccination in the United States. All children should receive four doses of IPV at 2 months, 4 months, 6 to 18 months, and 4 to 6 years. OPV (if available) may be used only for the following special circumstances:

1. Mass vaccination campaigns to control outbreaks of paralytic polio.
2. Unvaccinated children who will be traveling in <4 weeks to areas where polio is endemic or epidemic.
3. Children of parents who do not accept the recommended number of vaccine injections. These children may receive OPV only for the third or fourth dose or both; in this situation, health care professionals should administer OPV only after discussing the risk for VAPP with parents or caregivers.
4. During the transition to an all-IPV schedule, recommendations for the use of remaining OPV supplies in physicians' offices and clinics have been issued by the American Academy of Pediatrics (see Pediatrics, December 1999).

⁶ The 2nd dose of measles, mumps, and rubella (MMR) vaccine is recommended routinely at 4 to 6 years of age but may be administered during any visit, provided at least 4 weeks have elapsed since receipt of the 1st dose and that both doses are administered beginning at or after 12 months of age. Those who have not previously received the second dose should complete the schedule by the 11- to 12-year-old visit.

⁷ Varicella (Var) vaccine is recommended at any visit on or after the first birthday for susceptible children, i.e., those who lack a reliable history of chickenpox (as judged by a health care professional) and who have not been immunized. Susceptible persons 13 years of age or older should receive 2 doses, given at least 4 weeks apart.

⁸ Hepatitis A (Hep A) is shaded to indicate its recommended use in selected states and/or regions; consult your local public health authority. (Also see MMWR Morb. Mortal Wkly Rep. Oct. 01, 1999;48(RR-12); 1-37).

Barriers to Infant Immunization

Although the safety and efficacy of infant/childhood immunizations have been proven, there are still many barriers that exist that prevent protecting vulnerable population groups from vaccine preventable diseases. These multiple barriers are currently addressed in these areas:

• economic and cultural risk factors
• provider practices
• families
• inadequate knowledge

Economic and Cultural Risk Factors

Demographic and social support variables indicate that children are at risk for many diseases. Data from the CDC National Immunization Survey indicates that children living below the poverty level and that Black and Hispanic children had immunization rates below the national average (CDC 1997). A study in Baltimore found that children of teenage mothers, children in large families, and children whose mothers lack social support systems had lower immunization rates at age two. Most of these mothers believed that immunizations protected their children from disease and that these diseases had serious consequences. However, these parents also believed that timing of immunizations did not matter (Strobino, Keane, Holt, Hughart and Guyer 1996). A study of Mexican American mothers by Guendelman, English and Chavez (1995) found that children of mothers who smoked, drank alcohol, were unaware of child safety measures, had a stressful event since birth of the child, lived in chaotic households, or were new to their neighborhood had lower immunization rates. A large study of public and private patients in Texas by Suarez, Simpon and Smith (1997) found that immunization rates for families with private insurance and those using public clinics were the same, but families with Medicaid coverage had lower immunization rates. Families receiving Aid to Families with Dependent Children (AFDC) also had lower rates. Similarly, Houseman, Butterfoss, Morrow and Rosenthal (1997) found that mothers with fewer resources found it more difficult to succeed in obtaining immunizations for their children. Other identified risk factors include low parental educational level, low socioeconomic status, inability to access appropriate transportation, nonwhite race, single parent family, lack of parental care and a late start on the immunization series (Pruitt, Kline and Kovaz 1995). Knowledge of these risk factors for inadequate immunization must be incorporated into strategies to increase rates.

Provider Practices

Policies and procedures in office settings can be barriers to timely immunization. Missed opportunities are the most significant barrier among clinicians. Many reasons are given for this (Szilagyi et al. 1996): immunization status is not evaluated at each well child and acute care visit, immunizations are not given when the need is identified, immunizations are delayed for non-valid contraindications, all vaccines needed are not given at one visit and immunizations are not provided in the absence of a complete physical exam. Watson (1996) found that 78% of a group of public and private patients did not bring an immunization record to a visit. This percentage was the same for both well and acute child care visits to a provider.

Focus groups conducted (Houseman et al. 1997) identified additional practice setting barriers. These were:

• Parents were unable to obtain appointments in a timely manner, with some experiencing delays of 4-6 weeks. Families in stressed households found it difficult to effectively plan that far in advance.
• There were inflexible office schedules with immunizations only being administered by appointment, during a physical exam with no weekend or evening coverage.
• The office environment was frequently non-conducive with long waits for small children in crowded waiting rooms.
• Phone access was often difficult with frequent busy signals and being left on hold for long periods of time. These were considered inconvenient by many poor households without phones.
• Attitudes of staff in offices were frequently insensitive, with many mothers from low-income families feeling that staff treated them in a condescending manner, particularly if their child was behind schedule. They also felt that they were not given adequate explanations and information.
• Personal safety concerns were expressed about the location of some clinics.
• Parents had misconceptions about the safety of vaccines and their contraindications (Tables 4-5). Minor and serious side effects caused some parents to delay immunizations.

Table 5: Events Reportable to the National Vaccine Injury Compensation Program Following Vaccination

Vaccine	Adverse Event	Interval from vaccination (n)
Tetanus in any combination	Anaphylaxis or anaphylactic shock	7 days
same as above	Brachial neuritis	23 days
Pertussis in any combination	Anaphylaxis or anaphylactic shock	7 days
same as above	Encephalopathy	7 days
Measles, mumps, rubella in any combination	Anaphylaxis or anaphylactic shock	7 days
same as above	Encephalopathy	15 days
Rubella in any combination	Chronic arthritis	42 days
Measles in any combination in an immunodeficient recipient	Thrombocytopenic purpura	30 days
same as above	Vaccine-strain measles viral infection	6 months
OPV	Paralytic polio or vaccine-strain polio viral infection
same as above	- in a non-immunodeficient recipient	30 days
same as above	- in an immunodeficient recipient	6 months
same as above	- in a vaccine-associated community case	No limit

Strategies to Eliminate Barriers

In order to effectively achieve a 90% immunization level for our nation's children under the age of two, it is important to strengthen provider practices, educate parents and provide access to the under served, the uninsured, and the undocumented. Every child is important and will be served by these efforts. The following strategies should be operationalized.

Avoid Missed Opportunities to Immunize. In every setting — office, clinic, school, home, emergency room — health care providers can assess each child's immunization status. If immunizations are needed, immunize immediately, and if not possible, assist the parent to make arrangements for the child to be immunized as soon as possible. Develop referral mechanisms in practice settings.

Educate Staff and Parents. Information as well as continuing education programs should be available for staff in all settings to acquaint them with the Standards for Pediatric Immunization Practice (Table 6). Current vaccine administration guidelines are provided annually by the ACIP and are available in professional journals and directly on the CDC Internet site. As new vaccines become available, updates and inservice programs must be provided to all practitioners.

• Immunization services are readily available.
• There are no barriers or unnecessary prerequisites to the receipt of vaccines.
• Immunization services are available free or for a minimal fee.
• Providers utilize all clinical encounters to screen for needed vaccines and when indicated, vaccinate.
• Providers educate parents and guardians about immunization in general terms.
• Providers question parents or guardians about contraindications and, before vaccinating a child, inform them in specific terms about the risks and benefits of the vaccinations their child is to receive.
• Providers follow only true contraindications.
• Providers administer simultaneously all vaccine doses for which a child is eligible at the time of each visit.
• Providers use accurate and complete recording procedures.
• Providers co-schedule immunization appointments in conjunction with appointments for other child health services.
• Providers report adverse events following vaccination promptly, accurately, and completely.
• Providers operate a tracking system.
• Providers adhere to appropriate procedures for vaccine management.
• Providers conduct semiannual audits to assess immunization coverage levels and to review immunization records in the patient populations they serve.
• Providers maintain up-to-date, easily retrievable medical protocols at all locations where vaccines are administered. Providers practice patient-oriented and community-based approaches.
• Vaccines are administered by properly trained persons.
• Providers receive ongoing education and training regarding current immunization recommendations.

Parents also need education. They should be provided with the necessary information about reactions within 48 hours post inoculation that may require additional medical intervention. Although serious adverse events are rare, children who are seriously or fatally injured as a result of immunization can seek compensation through the National Vaccine Injury Compensation Program (Table 5). It is required that these be reported using the Vaccine Adverse Events Reporting System form available in all provider practices.

Identify Children in Need. Development of protocols for identification of children in need of immunization is imperative. Gill and Fisher (1997) found that three steps were useful in increasing immunization rates in a primary care setting: use of a tracking sheet recording the child's record, all dosages and contraindications, placing a stamp on each progress note for sick and well visits with nurses checking for immunizations on the progress note and alerting physicians. Reasons for non-administration of vaccine also were recorded.

Evaluate Existing Policies and Procedures. Office operation/environment can prove to be a barrier to infant immunization. Hughart et al. (1997) found that providing immunizations outside of regular well-child care visits would not necessarily decrease attendance at visits for well-child care. Office protocols should be developed to enable providers to automatically administer immunizations under standing orders (Gill and Fisher 1997).

Utilize a Tracking System. Computerized tracking systems can yield data to remind parents about appointments, to identify children with delayed immunizations, and to monitor and evaluate the practice efforts to reach the children in that particular practice. These programs will send postcards to parents as reminders. Alemi et al. (1996) found that the use of computer-generated telephone reminders to the parents' home was a very effective strategy to improve immunization rates.

Nursing Role in Immunization Practice

The leadership role undertaken by nurses in immunizing children is well-documented. They practice in multiple settings, are the largest number of health care providers and collaborate with many other professionals and groups. They are vital to the mobilization and outreach efforts of state coalitions, are frequently the first person seen by consumers in any health care setting, and have developed innovative programs for the immunization of children throughout the United States (ANA 1993). Their knowledge base, advocacy role and conceptual framework of health promotion and disease prevention provide a strong basis for their role in immunizing children.

Community health nurses in home care settings, clinics and schools can assess children for immunization status and immunize siblings at school settings. Nurses have been effective advocates linking immunization sites with other services such as Women Infants and Children (WIC) and Aid For Dependent Children (AFDC). Nurses have an opportunity to educate providers about registries and develop the needed linkages with provider practices in states. As educators, nurses utilize students in clinic settings, teach childhood immunizations physical assessment and also work in faculty practice settings/nurse-run clinics to make certain that children in all settings receive appropriate health care.

Conclusion

As we approach a new century, health care in America will undergo major changes, revisions and challenges. The health of children must remain a major priority. Their first line of defense against disease is immunizations. We are close to reaching a major goal of assuring that all children receive timely immunizations by the time they are two years of age. We must not allow the ravages of another measles or other epidemic to take the lives of our children. The next few years will be critical in this effort. Nurses have a significant challenge ahead to maintain their leadership role in the delivery of vaccine, to educate consumers, to collaborate with others to develop innovative strategies to eliminate barriers and to develop policies that will mandate that all children be immunized by their second birthday. Anything less than a total commitment to this effort on the part of all health care providers is unacceptable.

References