Clostridium perfringens is a bacterial strain that resides in the intestines of chickens. When the bacterium is able to multiply, it can cause necrotic enteritis within the gut. This disease can cause severe (damaged gut with lesions or sores leading to death) or mild (small lesions, lower body weight gain, high feed conversion ratio) symptoms and has a huge economic impact on the poultry industry. In the past, antibiotics were used as a growth promoter in order to fatten the animals. Since the ban of these drugs due to the concern of antibiotic resistance, the prevalence of the disease has risen. Vaccination could be a good alternative. Classic vaccination using a needle however is not applicable in the field. During this project, an oral vaccine will be developed that can be added to the feed or water supply of the animals. A modified Bacillus subtilis strain will be used as a vector to deliver and present an antigen to the immune system of the broiler. These resistant spores will be administered orally because they are able to survive the harsh conditions in the gastrointestinal tract. In order to extend the residence time in the gut and eventually increase the interaction with immune cells, the spores are made sticky. The best sticky molecule as well as the best antigen and expression site will be chosen in a step-by-step manner. After developing the optimal modified strain, its protective effect will be assessed in an infection trial.