Similar antibody concentrations in Filipino infants at age 9 months, after 1 or 3 doses of an adjuvanted, 11-valent pneumoccoccal diphtheria/tetanus-Conjugated Vaccine: a randomized controlled trial

In Filipino infants, 1 dose of an adjuvanted, 11-valent pneumococcal conjugate vaccine (serotypes 1, 4, 5, 7F, 9V, 19F, and 23F conjugated to tetanus protein; and serotypes 3, 6B, 14, and 18C conjugated to diphtheria toxoid) administered alone at age 18 weeks (11PncTD1) elicited similar antibody concentrations at age 9 months as those elicited by 3 doses (11PncTD3) administered concomitantly with national program vaccines, at ages 6, 10, and 14 weeks. Geometric mean antibody concentrations ranged from 0.36 mug/mL ( for serotype 18C) to 5.81 mug/mL (for serotype 4), for the 11PncTD1 vaccine, and from 0.32 mug/mL (for serotype 18C) to 5.01 mug/mL (for serotype 19F), for the 11PncTD3 vaccine. The proportion of infants with threshold antibody concentrations greater than or equal to0.35 mug/mL was also similar (ranges, 55.6%-100% for the 11PncTD1 vaccine and 42.9%-100% for the 11PncTD3 vaccine). The functional activity of antibodies expressed as opsonophagocytic activity titers was similar in the 11PncTD1 and 11PncTD3 groups. This finding is an important one for countries with financial constraints and high pneumococcal disease burden.