ATLANTA — Recommendations regarding use of the 23-valent pneumococcal polysaccharide vaccine in high-risk children aged 24–59 months who previously received the 7-valent pneumococcal conjugate vaccine remain to be finalized after discussion of the issues by the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention at its summer meeting.
Current recommendations call for use of 23-valent pneumococcal polysaccharide vaccine (PPV23) at 2 years of age following receipt of the 7-valent pneumococcal conjugate vaccine (PCV7) vaccine series prior to age 2 for children in certain high-risk groups, including those with HIV infection, asplenia, or immunocompromising or chronic conditions. The addition of PPV23 may also be considered among children of Alaska Native or Native American descent. For children aged 10 years or younger, one revaccination should be considered 3–5 years after the previous PPV23 dose.
Although data regarding the safety of PPV23 given after PCV7 are limited, the rationale for the recommendation is to provide additional serotype coverage among children at very high risk (MMWR 2000;49[RR-09]:1–38).
Dr. Pekka Nuorti of the CDC's Respiratory Diseases Branch presented the committee with three possible votes—drafted prior to the meeting by a working group—to clarify language from those recommendations. Of the three issues—use of PPV23 in Alaska Native and American Indian children, the time interval for PPV23 revaccination in high-risk children, and use of the PCV7 in HIV-infected school-age children—the committee ended up voting only on the third item.
That advice, still subject to approval by the CDC, was that providers “may consider” administering two doses of PCV7 followed by PPV23 in HIV-infected children aged 5–17 years on highly active antiretivinal therapy (HAART) who were not previously immunized with PCV7.
The ACIP also agreed with the working group's prior decision not to recommend use of PPV23 in children with asthma who are not on high-dose corticosteroid therapy, despite voting to recommend the vaccine for all adults with asthma. Diagnosis of pediatric asthma is difficult and many children outgrow wheezing, and current rates of invasive pneumococcal disease (IPD) are very low overall in children aged 2 years and older because of both the direct and the indirect impact of routine PCV7 use. Thus, PPV23 is also not recommended even for older adolescents with asthma who did not receive PCV7, Dr. Nuorti said in an interview.
The current American Indian/Alaska Native recommendation was based primarily on expert opinion, and there are few data on use of PPV23 in those populations of children after the PCV7 series. The recommendation also lacks specificity, because not all such groups are at equal risk and the group definitions are not always clear. Moreover, in practice PPV23 typically has not been used among these children except for those with high-risk medical conditions.
Because of concern about potential hyporesponsiveness after PPV23, the working group had prepared a recommendation against routine use of PPV23 in all American Indian/Alaska Native children and to limit its use to only those “living in areas with documented elevated rates of [IPD].” However, several committee members felt this still wasn't clear enough, so the decision was left for the working group to retool.