IMMUNOLOGY

Detailed explanation-1: -In May 1796, English physician Edward Jenner expands on this discovery and inoculates 8-year-old James Phipps with matter collected from a cowpox sore on the hand of a milkmaid. Despite suffering a local reaction and feeling unwell for several days, Phipps made a full recovery.

Detailed explanation-2: -Historically, CPXV, or at least cowpox, the disease, is associated with Edward Jenner and the smallpox ‘vaccination’, but the modern smallpox vaccine is vaccinia virus, corresponding to a different species in the same genus, Orthopoxvirus.

Detailed explanation-3: -The smallpox vaccine, introduced by Edward Jenner in 1796, was the first successful vaccine to be developed. He observed that milkmaids who previously had caught cowpox did not catch smallpox and showed that inoculated vaccinia protected against inoculated variola virus.