This clinical trial is focused on children who have a higher genetic risk of developing Type 1 Diabetes, a condition where the body’s immune system attacks the cells in the pancreas that produce insulin. The study aims to see if vaccinating these children against COVID-19 from the age of 6 months can reduce the chances of developing islet autoantibodies, which are markers that indicate the immune system is attacking the pancreas, or Type 1 Diabetes itself during childhood.

The treatment being studied is the Comirnaty Omicron XBB.1.5 COVID-19 mRNA Vaccine, which is a type of vaccine that uses a small piece of genetic material called mRNA to help the body recognize and fight the virus that causes COVID-19. This vaccine is given as an injection. Some participants in the study will receive this vaccine, while others will receive a 0.9% Sodium Chloride solution, which is a simple saline solution used as a placebo.

The study will follow the children over time to see if the vaccine helps in reducing the development of islet autoantibodies or Type 1 Diabetes. The main goal is to measure the time it takes for these conditions to develop after the children are randomly assigned to receive either the vaccine or the placebo. The study will continue until 2029, allowing researchers to gather enough information to understand the vaccine’s impact on preventing Type 1 Diabetes in children with a high genetic risk.