Primary Vaccination Site Reaction 1 cm Day4 Day7 1cm Day 14 Day 21 Major(primary)reaction Expected vaccine site reaction and progression following primary smallpox vaccination or revaccination after a prolonged period between vaccinations. ●Major (primary) reaction – Expected vaccine site reaction and progression following primary smallpox vaccination or revaccination after a p r o l o n g e d p e ri o d b e t w e e n v a c c i n a ti o n s