You are here Home Glossary of technical terms Glossary of technical terms hypotonic-hyporesponsive episode (shock, collapse) Listen Print Share Twitter Facebook Email The sudden onset of: pallor or cyanosis limpness (muscle hypotonia) reduced responsiveness or unresponsiveness This may occur after vaccination when no other cause is evident, such as a vasovagal episode or anaphylaxis. The episode usually occurs 1–48 hours after vaccination and gets better on its own without treatment. Page history Last updated 11 June 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