A Study to Learn About How a New Pneumococcal Vaccine Works in Adults

Launched by PFIZER · Jul 18, 2025

Keywords

ClinConnect Summary

This clinical trial is studying a new vaccine designed to protect adults against pneumococcal disease, which is caused by bacteria called Streptococcus pneumoniae. The main goal is to find out if the new vaccine is safe and well-tolerated by adults. Participants will receive either the new vaccine, one of two comparison vaccines, or a placebo (a treatment that looks like the vaccine but doesn’t contain any medicine). The study will last up to 18 months, during which participants may get up to two doses of the vaccine or placebo and will have regular check-ups to monitor their health and any side effects. Blood samples will also be taken to help researchers learn more about how the vaccine works.

Healthy adults who have either never had a pneumococcal vaccine before or who received one more than five years ago may be eligible to join. People who have had serious infections caused by the pneumococcal bacteria in the past will not be able to participate. If you take part, you can expect to visit the clinic several times for health checks and blood tests, and to share any side effects you might experience. This study is not yet recruiting participants but aims to ensure the new vaccine is safe before it can be used more widely.

Gender

ALL

Eligibility criteria

• Key Inclusion Criteria:
• • Healthy participants who are determined by medical history, physical examination (if required), and clinical judgment of the investigator to be eligible for inclusion in the study.
• • Participants either with no history of ever receiving a pneumococcal vaccine or who have received a pneumococcal vaccine more than 5 years prior to vaccination in this study
• Key Exclusion Criteria:
• • • Participants with a history of microbiologically proven invasive disease caused by S pneumoniae.