'''Prodromal''' is an early symptom indicating the onset of an attack or a [[disease]].<ref>http://www.cdc.gov/vaccines/about/terms/glossary.htm#p</ref>
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'''Prodromal''' is an early symptom indicating the onset of an attack or a [[disease]].<ref>https://www.cdc.gov/vaccines/about/terms/glossary.htm#p</ref>