Intradermal DNA vaccination in ear pinnae is an efficient route to protect cats against rabies virus

Abstract

-A DNA vaccine against rabies (pGQH) was administrated to cats in order to examine different administration routes. Four groups of three cats each were inoculated with pGQH as follows: group A, intramuscularly (IM), 100 µg; group B, intranasally (IN), 100 µg; group C, intradermally into ear pinnae (ID-EP), 100 µg, and group D, IM, 200 µL of phosphate buffer solution (PBS) alone (control group). Blood was drawn on days 0, 30, 60, 90, 120, 150, and 180. Groups A, B, and C received a booster on day 30. At day 200 all animals were challenged. A passive transfer of cat sera, as well as a viral challenge, was performed in mice. The results displayed that neutralizing antibody titers were higher in cats of group C (ID-EP) showing high early titers (> 2 IU) and the highest titer was on day 120 (> 14 IU). In group B (IN), two out of three cats seroconverted on day 30 (> 0.5 IU), the third cat seroconverted until day 60 (> 0.5 IU). In contrast, the lowest levels of neutralizing antibodies were detected in group A (IM). The control group showed no anti-rabies antibodies. Groups A (IM) and D (control) succumbed after lethal challenge. All animals from the ID-EP group (C) survived, only one individual from the IN (B) group died. Mice that received cat sera from ID-EP, IM, and IN groups survived and were protected (30/30 survivors). Mice groups that received pre-immunization sera from cats were not protected (0/30 survivors). This study demonstrates that pGQH immunization was successful when it was administrated ID-EP, and acceptable through the IN route. The IM route, however, was not effective in cats. For vaccination, the IN route seems attractive due to its accessibility for application, but it seems to activate seroconversion slowly. The best route to promote anti-rabies antibody titers was the ID-EP route. This practical and efficient route should be further studied.rabies / DNA vaccine / intradermal into ear pinna / intranasal / cats

Dendritic cell targeted Ccl3- and Xcl1-fusion DNA vaccines differ in induced immune responses and optimal delivery site

“…delivery of DNA vaccines in combination with electroporation. Indeed, most studies do not includes electroporation of the injection sites 23,44,45 , or only includes electroporation for one of the delivery methods 46 . Nevertheless, delivery of DNA by i.m.…”

“…In contrast, delivery of DNA i.d. has been reported to induce a more Th2/IgG1 polarized response 23,44 , and more protective antibody responses 46 . Our observations with Ccl3-HA fusion vaccines correlate well with these observations, with i.m.…”

DNA Vaccine Targeting Gonadotropin-Releasing Hormone Receptor and Its Application in Animal Contraception

“…This might be explained by the special structure of the pinna, which contains two layers of epidermis and dermis (separated by ear cartilage) with a high number of dendritic cells within a restricted area connected with major superficial cervical draining lymph nodes. Importantly, efficacy of intra-pinna DNA vaccination was shown in different species, including cats [41] and dogs [42]. For example, a single intradermal DNA immunization in ear pinna, given 1 year prior to infection, protected dogs against rabies virus [42,43].…”

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