Infectious Disease
PHASE2
● Phase II
Phase 2 Trial Evaluates mRNA Influenza Vaccines' Safety and Immunogenicity in Adults
ClinicalTrials.gov
Published March 27, 2026
Pfizer
NCT07431853 ↗
This Phase 2 study, sponsored by Pfizer, aims to evaluate the safety and immunogenicity of five mRNA-based influenza vaccines in a cohort of 770 healthy adults aged 18 and older. Participants will receive a single dose of either one of the experimental vaccines or an approved comparator vaccine, with follow-up over approximately 6 months. The primary endpoints focus on the percentage of participants experiencing prespecified local and systemic reactions, as well as adverse events following vaccination. Participants will attend at least three study visits, during which blood samples and nasal swabs will be collected to assess immune response. As the study is currently recruiting, specific statistical outcomes, such as hazard ratios, odds ratios, or p-values, are not yet available. The trial's findings will provide critical insights into the safety profile and immune response elicited by these mRNA vaccines, potentially informing future influenza vaccination strategies.
AI Accuracy Review: 8/10
· Auto-published
What if there was a way to tackle the flu more effectively? Every year, millions suffer from the flu, leading to missed work, school, and even hospital visits. Traditional flu vaccines have been around for a while, but they don't always provide the best protection. This new study is exploring mRNA vaccines, which have shown promise in other areas, like COVID-19. Participants in this study will receive one dose of either an experimental mRNA flu vaccine or a standard flu vaccine. Over six months, researchers will monitor how well these vaccines trigger the immune system to fight off the flu virus. The hope is that this could lead to a more effective way to prevent the flu and its complications. However, it's important to note that this is still in the early phases, and we need to see how safe and effective these new vaccines really are. If they work, we could be looking at a future where flu seasons are less severe, which is something everyone can look forward to.
What this means for you: A new mRNA flu vaccine could offer better protection, making flu seasons healthier for everyone.
View Original Abstract ↓
Status: RECRUITING | Phase: PHASE2
Condition(s): Healthy Adults
Intervention(s): Vaccine Candidate #1 (BIOLOGICAL), Vaccine Candidate #2 (BIOLOGICAL), Vaccine Candidate #3 (BIOLOGICAL), Vaccine Candidate #4 (BIOLOGICAL), Vaccine Candidate #5 (BIOLOGICAL)
The purpose of this study is to learn about safety in participants taking the study vaccine (mRNA-based vaccine) and the ability of the study vaccine to trigger the body's immune response, targeting the flu virus (influenza virus).
This study is seeking healthy participants 18 years of age or older. All participants in this study will receive only 1 dose in their arm, to deliver one of the experimental flu vaccines or one of the approved flu vaccines used for comparison.
Participants will take part in this study for about 6 months, and participants will need to visit the study site at least 3 times. A blood sample will be taken at each of the 3 planned study visits and a swab from inside the nose will be taken at the first study visit.
Primary Outcome(s): Percentage of participants reporting prespecified local reactions following vaccination; Percentage of participants reporting prespecified systemic events following vaccination.; Percentage of participants reporting adverse events (AEs) following vaccination.
Enrollment: 770 (ESTIMATED)
Lead Sponsor: Pfizer
Start: 2026-02-23 | Primary Completion: 2027-06-22
