You are here Home Glossary of technical terms Glossary of technical terms attenuation Listen Print Share Twitter Facebook Email The process of modifying a virus or bacterium to reduce its virulence (disease-inducing ability) while retaining its ability to induce a strong immune response (immunogenicity). Page history Last updated 11 January 2018 Last reviewed 11 June 2018 Is there anything wrong with this page? Help us improve the Australian Immunisation Handbook What you were doing? (required) What went wrong? (required) Leave this field blank