Heptavalent Pneumococcal Conju

By Laurie Barclay, MD
Medscape Medical News

July 7, 2003 — The heptavalent pneumococcal conjugate vaccine is well tolerated in human immunodeficiency virus (HIV)-positive infants without associated adverse effects, according to the results of a randomized trial published in the July issue of Pediatrics. However, the investigators caution that further research is needed for use in symptomatic HIV disease.

"Heptavalent pneumococcal conjugate vaccine (PCV) has been shown to be safe and effective in healthy infants and children," write Sharon Nachman, MD, from State University of New York Health Science Center at Stony Brook, and colleagues from the Pediatric AIDS Clinical Trials Group Study 292 Team. "However, little is known about its use in children who have HIV infection and are known to be at increased risk of developing pneumococcal infections."

In this double-blind trial, infants with HIV infection were randomized 2:1 to receive heptavalent PCV or placebo vaccinations, three doses at two-month intervals, starting at ages 56 to 180 days, and a booster dose at 15 months of age.

There were no differences in baseline characteristics in 30 infants who received PCV compared with 15 who received placebo. Of four subjects who experienced five severe acute reactions, three were in the PCV group and one was in the placebo group, and all had symptomatic disease at study entry.

The number and timing of new diagnoses through 24 months of age, including diagnoses of otitis media, were similar in both groups. However, among symptomatic subjects, the first new diagnosis occurred more rapidly among PCV recipients. Of three deaths during follow-up, two were in the PCV arm and one was in the placebo arm, and all were thought to be unrelated to study vaccine.

Primary immunogenicity measures, based on composites of fourfold changes in serotype-specific immunoglobulin G titers from preimmunization levels, showed significantly higher rates of response in the PCV arm. Asymptomatic and symptomatic infants who received PCV had similar immunologic responses for all serotypes.

Study limitations include low power to compare safety measures across arms and lack of long-term data on the longevity of the immune response.

"This study demonstrates that heptavalent PCV was well tolerated and not associated with vaccine-associated adverse reactions. Most important, this vaccine was immunogenic in the infant with HIV infection," the authors write. "However, additional studies of this vaccine (or others) must pay special attention to patients with symptomatic HIV disease, as they seem to be at higher risk for adverse events to any antigen."

One of the authors is employed by and has a direct financial interest in Wyeth, maker of the vaccine used in this study. Dr. Nachman serves as a consultant for Abbott, Bristol-Myers Squibb, GlaxoSmithKline, Wyeth, Boehringer Ingelheim, and Pfizer.

Pediatrics. 2003;112:66-73

Reviewed by Gary D. Vogin, MD