Safety and immunogenicity of heptavalent pneumococcal conjugate vaccine in Taiwanese infants

Abstract

Background and Purpose: The prevalence of antibiotic-resistant pneumococci has increased markedly in Taiwan since the 1990s. The prevention of pneumococcal infection by effective vaccination is an urgent need. The purpose of this study was to assess the safety and immunogenicity of heptavalent pneumococcal conjugate vaccine (serotypes 4, 6B, 9V, 14, 18C, 19F, 23F) in Taiwanese infants. Methods: Sixty healthy Taiwanese infants received heptavalent pneumococcal conjugate vaccine at 2, 4 and 6 months of age in an open-label, non-comparative trial. Routine diphtheria-tetanus-pertussis vaccines were concomitantly administered. Side effects were recorded and the antibody titer to each of the 7 pneumococcal serotypes was measured before vaccination and 1 month after the third vaccination. Results: Mild to moderate local reactions at the injection site were the common findings (17 to 30%) after vaccination but were not correlated with the number of vaccinations. Fever, restlessness, fussiness, and loss of appetite were the most common systemic reactions (22 to 53%). After 3 doses of vaccine, the geometric mean concentration of immunoglobulin G showed a significant rise (p < 0.001) to all 7 pneumococcal serotypes. More than 95% of infants had antibody titer ? 0.15 μg/mL of all serotypes, and 93% (serotype 23F) to 100% (serotypes 4 and 19F) of infants achieved an antibody titer ? 1 μg/mL. Conclusion: Inoculation with the heptavalent pneumococcal conjugate vaccine including the prevalent serotypes in Taiwan is safe and effective in preventing pneumococcal disease in Taiwanese children.