ABSTRACT
A rabies DNA vaccine consisting of plasmid DNA expressing the rabies virus surface glycoprotein was injected (im) twice at two week interval to outbred swiss mice or Bonnet monkeys (Macaca radiata) and the levels of rabies virus neutralizing antibody (VNA) titres were examined over a one year period. In mice, the VNA titre was maintained above the minimum protective level (0.5 I.U./ml) up to 10 months after primary immunization, while in monkeys, the titre dropped below the protective level by 6 months. An anamnestic B cell response was seen in both mice and monkeys following the administration of a booster dose, 10 and 6 months after the primary immunization, respectively. These results indicate that im injection of rabies DNA vaccine induces VNA in nonhuman primates and mice unlike intradermal (id) immunization, which was shown to induce VNA only in mice but not in monkeys. This is the first report on the induction of VNA in nonhuman primates by im inoculation of rabies DNA vaccine.
Subject(s)
Rabies Vaccines/immunology , Rabies virus/immunology , Vaccines, DNA/immunology , Animals , B-Lymphocytes/immunology , Injections, Intramuscular , Macaca radiata , Mice , Plasmids , Rabies Vaccines/administration & dosage , Vaccines, DNA/administration & dosageABSTRACT
Serum antibody assay of 1045 serum samples from birds vaccinated with Newcastle Disease vaccine by HI test and ELISA was carried out. Five hundred and twenty seven birds were challenged with virulent virus and data on HI test, ELISA and challenge test results were used for comparison. A good correlation between HI titres, ELISA absorbance and potency was observed indicating the usefulness of ELISA for potency estimation of vaccines and determination of immunization level in vaccinated flocks.
