2011 immunization schedules for infants, children and adolescents

New recommendations for use of meningococcal conjugate vaccine and the tetanus-diphtheria-pertussis vaccine for adolescents and adults will be included in the 2011 immunization schedule.

Each year, the Advisory Committee on Immunization Practices of the CDC, AAP and AAFP release updated immunization schedules for infants, children, adolescents and adults. A “catch-up” schedule that gives the recommended minimum intervals between doses for children whose vaccinations have been delayed is also updated. The annual updates include the changes in recommendations made the prior year. The new schedules are usually published the first of the year in Morbidity and Mortality Report, Pediatrics and American Family Physician and are available at the CDC website (www.cdc.gov/vaccines/recs/schedules/child-schedule.htm).

The schedules can be downloaded for office use from the CDC website. Copies of the schedules for children aged 0 to 6 years and children aged 7 to 18 years are also printed as tear-out pages in Pediatrics. The release of the 2011 schedule will be delayed until Feb. 11, because of the time it will take to receive final approval of the new recommendations for use of meningococcal conjugate vaccine (MenACWY; Menveo, Novartis) and Tdap adopted by the ACIP at its most recent meeting in October. These ACIP recommendations will become official when approved by the CDC and published in MMWR.

MenACWY: A two-dose primary series

Children aged 2 years and older who are at increased risk for meningococcal disease should receive MenACWY vaccine. The ACIP in October recommended a two-dose primary MenACWY series for patients who are at increased risk for meningococcal disease because of a persistent complement deficiency, asplenia or HIV infection. The rationale for this recommendation is better protection against meningococcus. A higher antibody level in children with complement deficiency is expected to offer better protection in this group of patients. A higher percentage of patients with asplenia respond better to a second dose of the vaccine than to a single dose. And in each of these three groups, the two-dose regimen is likely to offer a longer duration of protection. The second dose is given 2 months after the first dose.

Booster doses continue to be recommended for these and all other patients who remain at increased risk for meningococcal disease. If the patient receives the primary series at 2 to 6 years of age, the first booster dose is recommended 3 years later; if the patient was aged 7 years or older when the primary series was given, the first booster dose is given 5 years later. Subsequent booster doses for both groups of patients are given at 5-year intervals.

Patients with a complement component deficiency, asplenia or HIV infection who were previously vaccinated with a single dose of MenACWY should receive a booster dose at the earliest opportunity, and then continue to receive additional boosters at the appropriate interval.

A booster dose for all adolescents

For many years, ACIP and AAP have recommended routine vaccination of adolescents with MenACWY, beginning at age 11 to 12 years, with catch-up of all previously unimmunized adolescents aged 13 to 18 years. In October, the ACIP added a recommendation for a booster dose of MenACWY at 16 years of age for children initially vaccinated at 11 to 12 years of age. For adolescents who were older than 13 years when initially vaccinated, a one-time booster dose should be given 5 years after the first dose, up to age 21 years of age. The rationale for the booster recommendation for adolescents is that post-immunization anti-meningococcal antibody data suggest that protection from a single dose of MenACWY will wane within 5 years after vaccination. The booster dose will provide protection during late adolescence and during the first year of college, when adolescents experience an increased incidence of meningococcal disease.

Pertussis

Experience during the current pertussis outbreak in California and additional safety data on adverse events when giving Tdap after a tetanus and diphtheria toxoids vaccination have led ACIP to make changes in the recommendations for use of Tdap in children who have not completed the five-dose childhood DTP/DTaP vaccination series or four doses of DTP/DTaP if the fourth dose was administered at age 4 years or older, in 19- to 64-year-olds who need a pertussis booster, and in adults aged 65 years and older.

Tdap should be routinely given at the 11- to 12-year-old visit. For children aged 13 years and older who have not received Tdap, the vaccine should be given at the next appropriate visit. It was initially recommended that under most circumstances, a child aged 11 years and older who needed a pertussis booster should wait a minimum of 2 years from the last Td immunization. This recommendation was made based on the concern that diphtheria and/or tetanus toxoid administration at an interval shorter than 2 years may lead to an increase in adverse events.

Additional safety data show no increase in adverse events from a Tdap immunization given after a dose of a tetanus- or diphtheria-containing vaccine when given at an interval of less than 2 years compared with 2 years or more. Therefore, in October, the ACIP removed the interval recommendation. Adolescents who have not received a dose of Tdap should be immunized as soon as feasible. Tdap can be administered regardless of interval since the last tetanus- or diphtheria-containing vaccine. This recommendation also applies to patients aged 19 to 64 years.

The ACIP also recommended that adults aged 65 years and older who have or who anticipate having close contact with an infant younger than aged 12 months (eg, grandparents, childcare providers and health care practitioners) and who have not previously received Tdap should receive a single dose of Tdap to protect against pertussis and reduce the likelihood of transmission of pertussis to these vulnerable infants.

Tdap and children aged 7 to 10 years

Previously, there was no recommendation for pertussis immunization for a child aged 7 to 10 years because none of the available pertussis-containing vaccines was licensed for this age group. However, because of the excellent safety record of Tdap and the expectation that the vaccine will be immunogenic in this age group, the ACIP recommended off-label use of Tdap for these children to protect them against pertussis infection and disease. Children aged 7 to 10 years who are not fully immunized against pertussis and for whom no contraindication to pertussis vaccine exists should receive a single dose of Tdap to provide protection against pertussis. If additional doses of tetanus- and diphtheria toxoid-containing vaccines are needed, then children aged 7 to 10 years should be vaccinated according to catch-up guidelines. Further guidance will be forthcoming on timing of revaccination in patients who have received Tdap before age 11 years.

PCV13

In February 2010 a 13-valent pneumococcal conjugate (Prevnar 13, Wyeth) was licensed by the FDA. PCV13 replaced PCV7 (Prevnar, Wyeth), which had been in use for the past 10 years. PCV7 was remarkably effective, virtually eliminating invasive pneumococcal disease (IPD) caused by the seven serotypes in the vaccine in children younger than 5 years. PCV7 also protects recipients from colonization with the serotypes in the vaccine. This resulted in a decreased circulation of those serotypes in the general population and a significant reduction in IPD cases in adults caused by the vaccine serotypes as well. However, other serotypes, known as “replacement serotypes,” have emerged, which has led to a small but significant increase in IPD cases. PCV13 includes the original seven serotypes in PCV7 and six additional serotypes.

The six new serotypes in the vaccine are currently responsible for more than 60% of IPD occurring in children younger than 5 years. PCV13 is given in a four-dose series, similar to PCV7. Transition from PCV7 to PCV13 availability has now been completed. Children whose PCV series began with PCV7 should complete the PCV series with the appropriate number of PCV13 doses needed to complete the four-dose recommended schedule. In addition, healthy children younger than 59 months, who have already received four doses of PCV7, should receive a supplemental dose of PCV13 to provide them with the expanded pneumococcal serotype coverage offered by PCV13. Children to 71 months of age who are at high risk for IPD because of an underlying condition, who completed their series with PCV7, should receive a single dose of PCV13. The supplemental dose of PCV13 should be administered at least 8 weeks after the previous dose of PCV7. In addition, children aged 72 months to 16 years at high risk for IPD may receive a single dose of PCV13.

Summary

When the new schedules become available, providers should familiarize themselves with the changes in the schedules and the accompanying footnotes for individual vaccines. The footnotes contain important information necessary for proper use of vaccines. Many footnotes have been rewritten to improve clarity and readability. It is also important for providers to be aware of changes in recommendations from ACIP or AAP made during the year. New recommendations can be found in AAP News, at Red Book online, at the ACIP website and in Infectious Diseases in Children.

Joseph A. Bocchini Jr., MD, is an Infectious Diseases in Children Editorial Board member.

Disclosure: Dr. Bocchini has no direct financial interest in any of the products mentioned in this article nor is he a paid consultant for any companies mentioned.