Altered or impaired immune response upon vaccination in WNIN/Ob rats

The present study was aimed to study the immune response in three months old male and female naïve obese animals and upon hepatitis B vaccination in three months old female WNIN/Ob obese mutant rats, established at our institute in comparison with its lean litter mates. Altered immune profile was seen in naïve obese mutant rats in terms of percentage of splenic CD8(+) cytotoxic cells in males and percentages of splenic CD3(+) T lymphocytes and CD4(+) T helper cells in females respectively. Furthermore these obese mutant rats also exhibited impaired immune response to hepatitis B vaccine with low specific Hepatitis B surface antigen (HBsAg) specific IgG response and splenic lymphocyte proliferative response to HBsAg compared to the lean counterpart. The loss of immunological memory following vaccination could be attributed to the metabolic and hormonal changes associated with obesity. This observation has implication in public health policies related to vaccination in developed as well as developing countries.