Efficacy, safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in children. Northern California Kaiser Permanente Vaccine Study Center Group.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 10749457 · doi:10.1097/00006454-200003000-00003
What was done
A double-blind randomized controlled trial evaluated the heptavalent CRM197 pneumococcal conjugate vaccine (PCV) in 37,868 infants randomized 1:1 to receive either PCV or a meningococcal type C CRM197 conjugate control vaccine at 2, 4, 6, and 12 to 15 months of age. The primary outcome was invasive disease caused by vaccine serotypes. Secondary outcomes included overall invasive disease, clinical otitis media visits and episodes, frequent and severe otitis media, ventilatory tube placement, and serotype-specific otitis media efficacy evaluated in spontaneously draining ears.
What was found
In the fully vaccinated per-protocol analysis through April 1999, 40 cases of vaccine-serotype invasive disease occurred (39 in controls, 1 in PCV) for a vaccine efficacy of 97.4% (95% CI, 82.7% to 99.9%). In the intent-to-treat analysis, 52 cases occurred (49 in controls, 3 in PCV) for an efficacy of 93.9% (95% CI, 79.6% to 98.5%). There was no evidence of an increase in disease caused by nonvaccine serotypes. Efficacy against otitis media visits, episodes, frequent otitis, and ventilatory tube placement was 8.9%, 7.0%, 9.3%, and 20.1%, respectively (P < 0.04 for all). Serotype-specific effectiveness in spontaneously draining ears was 66.7%. Specific safety and immunogenicity numeric data were not reported in the abstract.
Why it matters
This landmark trial established that the 7-valent pneumococcal conjugate vaccine is highly protective against invasive pneumococcal disease in infants and provides modest but significant reductions in otitis media episodes and tube placements.
Limits
The study was conducted within a single health maintenance organization in Northern California, which may limit generalizability to areas with different serotype distributions. Specific quantitative safety and immunogenicity results were omitted from the abstract.
Cited by
- supports The original Prevnar pneumococcal vaccine clinical trial used a meningitis vaccine as a control instead of a saline placebo.