The Japanese word for Japan is æ¥æ¬, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, the Old Book of Tang.
Primary versus Secondary Immune Response The primary immune response occurs the first time that the immune system comes in contact with the antigen.
A secondary immune response (second exposure to an antigen) is not only faster but produces antibody with up to a 10,000 fold increase in binding affinity. This higher affinity comes from a mechanism that alters the variable regions of light and heavy chains of the memory cells by specific somatic mutation.