NCT03898986

The Effects of Attenuated Versus Inactivated Flu Vaccine in Twin Sets

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 18 (actual)
• Sponsor: Stanford University · Academic / Other
• Sex: All
• Age: 2 Years – 20 Years
• Healthy volunteers: Accepted

Summary

This is one project of a larger ongoing study related to the immune system's response to the flu virus. This study is designed to investigate the immune response to the live attenuated influenza vaccine (LAIV) vs. the Inactivated Influenza Vaccine (IIV) in identical and fraternal twins.

Detailed description

This is a Phase I mechanistic study of licensed influenza vaccines. The study requires 10 monozygotic and 10 dizygotic sets of twins (40 total participants) to enroll. The duration of the study for an individual volunteer will be 4 weeks including screening and active participation. The study has a total of 3 visits. First visit: Procedures during this visit are: Informed consent process, enrollment, study assessments, 20 ml blood draw, and vaccination. Participants will be randomized to receive either LAIV or IIV. The time required to complete the first study visit will be about 30-40 minutes. 2nd (day 7 post vaccination) and 3rd (day 28 post vaccination ) visit: 20 ml blood will be obtained and the visit will take approximately 15 minutes.

Conditions

• Influenza

Interventions

Type	Name	Description
BIOLOGICAL	Live attenuated influenza vaccine (LAIV4)	LAIV4 vaccine dosage is 0.2 mL. The vaccine will be administered as an intranasal spray. Each sprayer contains a single dose of FluMist® Quadrivalent; approximately one-half of the contents should be administered into each nostril. 0.1 mL (i.e., half of the dose from a single FluMist sprayer) is administered into each nostril while the recipient is in an upright position. Insert the tip of the sprayer just inside the nose and rapidly depress the plunger until the dose-divider clip stops the plunger. The dose-divider clip is removed from the sprayer to administer the second half of the dose (0.1 mL) into the other nostril.
BIOLOGICAL	Inactivated Influenza Vaccine (IIV4)	IIV4 vaccine will be administered as a 0.5 mL dose, with a sterile, disposable syringe and needle by IM injection.

Timeline

• Start date: 2019-10-08
• Primary completion: 2023-12-31
• Completion: 2023-12-31
• First posted: 2019-04-02
• Last updated: 2025-03-06
• Results posted: 2025-03-06

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated drug study