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This trial has completed recruitment on this platform, and is no longer accepting new referrals.

A clinical trial of an investigational seasonal flu vaccine for adults

Trial ID: mRNA-1010-P303
The Ignite P303 Trial is a Phase 3 clinical trial conducted by Moderna to evaluate an investigational vaccine to see if it can protect people from getting sick if they come into contact with the influenza virus, the virus that causes seasonal influenza (also known as the seasonal flu).

Trial Details

The Ignite P303 Trial will look at the safety and immune response of an mRNA-based investigational vaccine, called mRNA-1010, aimed at preventing seasonal flu in adults aged 18 and older.

Seasonal flu is a respiratory illness caused by the influenza virus. This virus infects the lungs and breathing passages and is easily spread from person to person. Every year, seasonal flu causes 3 to 5 million cases of severe illness and up to 650,000 deaths worldwide.

Our hope is that an mRNA-based investigational vaccine may offer protection by responding to changes in seasonal flu strains quickly and creating strong immune responses.

Estimated Enrollment

6,000 Participants



Eligibility Criteria

Participants must:

  • Be at least 18 years old
  • Be in generally good health

Participants must not:

  • Have received a seasonal flu vaccine within the past 6 months
  • Have had a confirmed flu infection within the past 6 months
  • Be pregnant or planning on becoming pregnant for at least 3 months following the vaccine visit

Site Locations

Participants will need to go to one of the clinics taking part in this clinical trial.

Sites are located in the cities/states identified with the red pin:

What to Expect

Participation in the Ignite P303 Trial will last approximately 7 months and includes 2–4 visits to a trial site and 2 to 3 phone calls. Additional visits may be required.

Participants will be given 1 injection in the upper arm. Participants will be randomly assigned to receive the investigational vaccine, mRNA-1010, or the currently approved seasonal flu vaccine. All trial participants will receive the same level of quality care regardless of which vaccine they receive.

Participants will also be asked to complete electronic diary (eDiary) entries every day for 7 days, starting on the day of injection.

Insurance is not needed to participate, and qualified participants will receive payment for their trial-related time and travel.

Frequently Asked Questions (FAQs)