Influenza Vaccines

To compare the immunogenicity, cellular immune response, and safety between adjuvanted (aIIV4) and non-adjuvanted (IIV4) seasonal influenza vaccines in the Taiwanese elderly population with chronic medical conditions.

The goal of this clinical trial is to measure the immune response in the blood, nose, and lungs after participants receive either the FDA-approved inactivated influenza vaccine or the FDA-approved intranasal FluMist vaccine. The study will evaluate immune responses in groups of healthy, non-pregnant, volunteers between the ages of 18 and 40. The main purpose of the study is to measure the change in influenza vaccine-specific antibodies in the lower lungs and nose between vaccination and 14 days after participants receive the vaccine. All participants will be randomized to receive one of the two seasonal flu vaccines and will have blood and back of the nose swabs collected throughout the study. Some study participants will choose to undergo optional bronchoscopy procedures and will be included in the part of the study looking at lower lung immune responses.

This study aims to assess the impact of a vaccine chatbot on improving influenza vaccination uptake among children aged between 6 and 59 months through a cluster randomized trial. Specifically, the main questions it seeks to answer are whether an AI-enabled vaccine chatbot will increase the uptake of influenza vaccine among children and their family members, and how it will influence parents' literacy and confidence towards influenza vaccine. It will explore the potential role of vaccine chatbot on vaccination services. A cluster randomization will be used to assign children to the intervention and control groups. Parents of children in the intervention group will be invited to use the influenza vaccine chatbot online through WeChat, the mostly widely used social media platform in mainland China, or any web browsers. They can ask any questions related to the influenza vaccine and receive validated answers from the chatbot immediately. The intervention will last one and a half months, with invitations sent every ten days to reinforce the engagement. The control group will not use the chatbot during the intervention duration. After the intervention, the uptake, literacy, and confidence towards influenza vaccine will be compared between the intervention and control groups to evaluate the impact of vaccine chatbot.