Natural History of Systemic and Nasal Mucosal Immunity After Influenza Vaccination in a Pediatric Population

Background: The influenza (flu) virus infects millions around the world every year. Children are at increased risk of complications from the flu. The flu vaccine protects against influenza, but the vaccine can be improved. Researchers want to learn more about children s mucosal and systemic immunity after flu vaccination. This could help to develop more effective flu vaccines in the future. Objective: To learn what happens in kids immune systems after receiving a flu vaccine. Eligibility: Children ages 2-17 who have received a flu vaccine in the past and plan to get the current seasonal flu vaccine given by injection. Design: All study visits will take place at home and communication with the study team will be done via phone or videoconference. Participants will review medical history and flu vaccination history with the study team. Participants will get the flu vaccine at their local doctor s office or pharmacy. They will not be given the vaccine in this study. Participants will complete an electronic survey to give details about the date and type of flu vaccine received. Participants will collect nasal and fingerstick samples at home. They will collect 4 nasal samples and 3 fingerstick samples over 6 months: once before they get the flu vaccine and 2-3 times after they get the vaccine. They will use collection kits that include instructions, sample collection supplies, and shipping materials. They will ship all samples back to NIH with all costs covered by NIH. Participation will last for 6 months. Compensation is provided.