Pfizer Inc. (NYSE:PFE) on Wednesday reported positive Phase 2 data for its investigational 25-valent pneumococcal conjugate vaccine candidate.

The study showed strong immune responses in infants compared with PREVNAR 20, supporting advancement into Phase 3 testing.

Stronger Immune Response Against Serotype 3

According to Pfizer, the vaccine candidate, known as 25vPnC, generated notably stronger immune responses against serotype 3, a major remaining cause of invasive pneumococcal disease and complicated pneumonia in children.

One month after the third dose, geometric mean titers for serotype 3 were 8.8 times higher with 25vPnC than PREVNAR 20.

After the fourth dose, titers were roughly 15 times higher than the comparator vaccine.

Pfizer said the vaccine candidate could potentially cover up to 90% of disease-causing serotypes in children younger than five ...