The V114-032 trial, presented at ESPID 2026, finds that administering the 15-valent pneumococcal conjugate vaccine (PCV15) reduces the incidence of first vaccine-type acute otitis media (VT-AOM) among healthy children.
“While the implementation of PCVs has significantly reduced pneumococcal AOM, randomized efficacy data for higher-valency PCVs are still lacking,” said lead author Dr Alvino Maestri from Merck & Co, Inc, in Rahway, New Jersey, US.
Hence, a parallel-group, double-blind, case-driven study involving 199 healthy children (median age 9 years, 48 percent female) was conducted. Participants were randomly assigned to either the PCV15 group (n=3,560) or a non-PCV control group (n=3,559), while also receiving standard paediatric vaccines. PCV15 was administered at 2, 4, 6, and 12 months (three + one dosing), and routine surveillance was performed digitally and via telephone to actively monitor AOM status. [ESPID 2026, abstract EPV-0238]
Among participants who experienced an AOM episode, defined as AOM detected by PCR and diagnosed ≥14 days after the third PCV15 dose, those who received PCV15 had a lower incidence of first VT‑AOM (0.99 vs 1.76 per 100 person‑years) and of all pneumococcal AOM of any serotype (2.34 vs 3.59 per 100 person‑years) than the control group.
PCV15 demonstrated an efficacy of 43.71 percent against VT‑AOM and 34.9 percent against all pneumococcal AOM, regardless of serotype.
Moreover, PCV15 consistently demonstrated a lower incidence of first VT-AOM caused by PCV7 (0.61 vs 1.17 per 100 person‑years) and PCV13 (0.99 vs1.76 per 100 person‑years) serotype subsets in the PCV cohort compared with the non-PCV cohort, yielding vaccine efficacies of 47.86 percent and 43.71 percent, respectively.
Taken together, children who received PCV15 had fewer AOM episodes, including subsequent episodes, than those who did not (51 vs 94 episodes; 1.06 vs 1.94 per 100 person‑years), corresponding to a vaccine effectiveness of 45.12 percent.
Serious adverse events were similar in both the PCV15 and non-PCV groups (27.1 percent vs 28.4 percent), and no vaccine discontinuation occurred in either group.
Overall, “PCV15 reduced the incidence of VT-AOM by nearly half, with consistent efficacy against all pneumococcal AOM regardless of serotype,” said Maestri.
The study results confirm the public health benefits of PCV15 in preventing AOM among infants and toddlers, he added.