Pediatric Immunization Update

September is here again, and with it comes "back-to-school" time? mostly dreaded by children, but sometimes eagerly awaited by parents. The arrival of the new school year often brings with it many questions from parents regarding vaccines and immunizations. This year additional focus has been placed on pediatric immunizations, with Surgeon General Richard Carmona highlighting the importance of vaccinations as part of the "Year of the Healthy Child" agenda, and in light of the recent celebration of National Immunization Awareness Month in August. This enhanced focus on timely immunizations for children, coupled with media coverage of vaccine safety issues, means that now, more than ever, pharmacists should be prepared to field questions and allay the concerns of parents regarding this important health issue.

In order to answer the questions and concerns of parents, pharmacists must be informed about all childhood vaccines: their timing, precautions and contraindications, adverse effects and safety, recent updates, and potential changes in the future. This article will focus on some of these updates and changes that are right on the horizon.

Fortunately, a wealth of information for both health care professionals and parents alike is readily available from a variety of sources, including the Internet. Unless parents are provided with trustworthy Web sites or literature providing accurate information, however, they are likely to be misled or confused.

Parents also may ask why it is important to vaccinate against infectious diseases not seen for years. They need to know that, if children are not routinely immunized, diseases that have been out of the public domain for decades would surely stage a comeback, because these diseases still exist. It is estimated, for example, that 2.7 million deaths worldwide would occur from measles alone if vaccinations ceased.

Vaccine Schedule Changes

No changes have been made this year to the US Recommended Childhood and Adolescent Immunization Schedule, which was first published in April 2004. This schedule contains 3 documents: the original schedule for children and adolescents from birth through age 18; and 2 catch-up schedules, one for those starting late or more than 1 month behind in their immunizations for children aged 4 months through 6 years, and one for children aged 7 to 18.

All schedules have been adopted by the Advisory Committee on Immunization Practices (ACIP), the American Academy of Pediatrics (AAP), and the American Academy of Family Physicians. The 2004 schedule updated previous ones by adding the recommendation that, beginning in the fall of 2004, healthy children aged 6 to 23 months, as well as household contacts and out-of-home caregivers for healthy children aged 0 to 23 months, receive an annual influenza vaccine. The ACIP periodically reviews these schedules to ensure that they reflect any changes in vaccine formulations, the use of existing licensed vaccines, or newly licensed vaccines.

The vaccines included in the current (2005) schedule are hepatitis B (HepB); diphtheria, tetanus, and pertussis (DTaP); Haemophilus influenzae type b (Hib); inactivated polio virus (IPV); measles, mumps, and rubella (MMR); varicella (chickenpox); pneumococcal conjugate (PCV); influenza; and, for select patients, hepatitis A.

Recent Updates

Since the January 2005 release of the Recommended Childhood and Adolescent Immunization Schedule, a recommendation update has been published by the ACIP and the AAP concerning meningococcal vaccines. Annually, 1400 to 3000 cases of invasive meningococcal disease (IMD) occur in the United States. Although this incidence is considered relatively low, with 0.5 to 1.1 cases per 100,000 individuals, the fatality rate and disease sequelae can be significant.

IMD occurs with 2 peak incidence levels: in infants under 12 months of age and in adolescents aged 15 years and older. Whereas the peak in infancy occurs at a higher rate, the adolescent peak contains the highest number of patients presenting with meningococcemia without meningitis and shock, and it also has the most fatal outcomes. College freshmen living in dormitories also are at increased risk.

Seventy-five percent of all meningococcal disease incidents in persons aged 11 to 18 years are caused by 1 of 4 serotypes. The AAP previously recommended the use of tetravalent meningococcal polysaccharide vaccine (MSPV4) to provide immunity against these serotypes in certain high-risk children and adolescents, such as travelers to countries with epidemic or hyperendemic meningococcal disease and those with functional or anatomic asplenia, or for use in controlling outbreaks. The AAP guidelines regarding IMD and college freshmen emphasized education about the disease and the availability of the vaccine, with no specific vaccination recommendations.

The development of a new tetravalent conjugate vaccine (MCV4) helps provide protection against the 4 most common serotypes. It was approved by the FDA in January 2005 for persons aged 11 to 55, and it has led to updated recommendations for prevention and control of IMD. MCV4 provides an improved booster response and perhaps longer immunity than MSPV4.

The new recommendations for immunization with MCV4 include adolescents at the 11-to 12-year visit, and at high school entry or age 15 years, whichever occurs first. Entering college freshmen who plan to reside in dormitory-style environments also should be routinely immunized. In addition, children aged 2 to 10 years at increased risk of meningococcal disease should be immunized with MSPV4 because MCV4 is not licensed for this age group.

Future Changes

Once supplies of the new MCV4 are abundant, it is likely that routine immunization for all adolescents will be recommended. It is expected that information on the duration of immunity and the need for reimmunization with MCV4 also will be available within 3 years. Moreover, studies are currently under way in an effort to approve MCV4 for use in children aged 2 to 10 years.

Other vaccines in the approval pipeline for pediatric patients include an optional second dose of varicella vaccine (currently, a single dose is recommended); hepatitis A vaccine for select patients 12 months and older (currently, for select patients 24 months and older); rotavirus vaccine for administration at 2, 4, and 6 months of age; human papillomavirus (HPV) vaccine given in a 3-dose series for individuals aged 11 to 26 years; and a measles, mumps, and rubella vaccine in combination with varicella vaccine (MMRV).

Given the importance of following immunization schedules for children and teens, it is imperative that pharmacists make every effort to stay current on changes and updates in the world of vaccines. Rapid advances in biotechnology continue to bring new weapons in the war against vaccine-preventable disease, as the new meningococcal product demonstrates. Pharmacists need to stay informed for the benefit of parents and children, whose health depends on it!

Vaccine Information Statements

The National Childhood Vaccine Injury Act requires that all health care providers give parents of patients copies of Vaccine Information Statements before administering each dose of the vaccines listed in the schedule. Additional information is available from state health departments and at www.cdc.gov/nip/publications/vis.

Detailed recommendations for using vaccines are available from package inserts, ACIP statements on specific vaccines, and the 2003 Red Book (3). ACIP statements for each recommended childhood vaccine can be viewed, downloaded, and printed from www.cdc.gov/nip/publications/acip-list. htm (the CDC National Immunization Program Web site). In addition, guidance on obtaining and completing a Vaccine Adverse Event Reporting System form is available at www.vaers.hhs.gov or by calling 800-822-7967.

LCDR Newman is a senior pharmacy officer with the US Public Health Service/Federal Bureau of Prisons, US Medical Center for Federal Prisoners, Springfield, Mo. The opinions expressed are those of the author and do not necessarily reflect the views of the US Public Health Service or the Federal Bureau of Prisons.