
Intramuscular injection of genetic vaccines elicits high cellular immune response and comparatively less humoral response. To understand the factors contributing for immune response in vivo FMDV antigens presented through calcium phosphate nanoparticle as well as naked DNA was injected in guinea pigs and bioavailability was studied. Analysis of mRNA expression in different tissues at various points of time by RT-PCR for a period of 300 days showed that the DNA vaccine presented through calcium phosphate nanoparticle produced transcripts up to 240 days whereas, naked DNA injected animals showed mRNA transcripts up to 120 days. FMDV specific antibodies sustained longer duration in nanoparticle delivered animals than naked DNA injected animals. Also the histopathology analysis of the injected muscle showed no major pathological lesions in both nanoparticle as well as naked DNA injected muscle tissue.