1.B-cells form humoral or mediated immune system (AMIS).
2.They defend against viruses and bacteria that enter the blood and lymph.
3.They form plasma cells and memory cellsby the division.
1.T-cell form cell-mediated antibody immune system (CMIS).
2.They defend against pathogens including protists and fungi enter the cells.
3.They form killer, helper and and suppressor cells by the division of lymphoblasts.
(b) Hepatitis-B vaccine is produced from surface antigens of transgenic yeast by DNA technology. The antigens represent whole protein vaccine.