RESUMO
The efficacy of a new recombinant FeLV vaccine (rFeLV), delivered transdermally via a needle-free delivery device was compared to that of an inactivated FeLV vaccine (FeLV-k), administered subcutaneously, with a conventional needle and syringe. Kittens were immunized with either rFeLV (0.25 ml, transdermal) or FeLV-k (1 ml, subcutaneous); or they were sham-vaccinated with physiologic saline (0.25 ml, transdermal). Two vaccinations were administered 21 days apart. Injection sites were monitored for any acute or subacute reactions relative to vaccine administration. Four weeks following the final vaccination, all cats were subject to oro-nasal FeLV challenge. Blood was collected for determination of FeLV antigenemia (p27) at weekly intervals beginning three weeks post-challenge. All of the vaccinated cats from both groups resisted FeLV challenge; and 90% of the control cats developed persistent FeLV antigenemia in response to challenge. No acute or persistent injection site reactions were observed. The rFeLV, delivered transdermally, provides protection against persistent FeLV antigenemia following a robust challenge that is equivalent to that of FeLV-k.
Assuntos
Vírus da Leucemia Felina/imunologia , Leucemia Felina/prevenção & controle , Proteínas Oncogênicas de Retroviridae , Vacinação/veterinária , Vacinas Virais , Administração Cutânea , Animais , Antígenos Virais/sangue , Gatos , Injeções Subcutâneas/veterinária , Distribuição Aleatória , Proteínas Oncogênicas de Retroviridae/administração & dosagem , Proteínas Oncogênicas de Retroviridae/normas , Segurança , Organismos Livres de Patógenos Específicos , Resultado do Tratamento , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/normas , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/normas , Vacinas Virais/administração & dosagem , Vacinas Virais/normasRESUMO
A whole killed FeLV vaccine was developed. By use of a chromatography method of purification and concentration, the resulting vaccine has been shown to be significantly lower in bovine serum albumin and total protein contents than were the same ingredients in the starting materials. The virus was inactivated or killed as an essential part of the vaccine development process. Vaccination trials with the vaccine without use of adjuvants indicated appreciable virus-neutralizing serum titer (greater than or equal to 1:10) in 107 of 110 vaccinated cats. Of 43 cats vaccinated and subsequently challenge exposed with virulent FeLV, only 2 developed persistent virus antigenemia (longer than 1 month), whereas 14 of 22 nonvaccinated control cats developed persistent viremia. In field tests, 2,770 cats from 6 states were vaccinated and observed. Postvaccinal reactions were not observed.
