Training periods in healthcare and free welfare settings are frequently obligatory. Temporary trainees frequently lack sufficient knowledge regarding hygiene and prevention of infections. Therefore, specific preventive measures for trainees need to be implemented in a standardized fashion, similar to those applied for permanent employees. These are legally regulated by the European Biological Agents Ordinance and the German Standing Committee on Vaccinations (STIKO) recommendations. Criteria regarding immunization against hepatitis A and B, measles, mumps, rubella, varicella, pertussis, diphtheria, tetanus, polio, influenza and COVID-19 are described. Immunization gaps should be closed at any opportunity in general (e.g. in adolescents during regular physician contacts) and specifically in medical students during the first semester and in other healthcare trainees before the start of the training period. Furthermore, individual introduction of trainees to their work areas and in particular education in health measures to protect themselves and also individuals under their care is of high importance. Education should include information on the potential risks of infection, hand hygiene practice and other personal protection measures.© Springer Medizin Verlag GmbH, ein Teil von Springer Nature 2021.