Imunogenicidade e segurança da vacina de febre amarela 17DD atenuada em primatas neotropicais

Abstract

Yellow fever (YF) is an acute infectious disease caused by the yellow fever virus (YFV), transmitted mainly by mosquitoes and endemic in tropical areas of South America. neotropical non-human primates are susceptible to infection, often occurring as outbreaks epizootic. The attenuated YF 17DD vaccine has already been used in howler monkeys and has shown to be effective in developing neutralizing antibodies against YFV, without adverse effects or reversal of virulence and disease development. The goal was then to evaluate the development of an immunological response through the induction of antibodies against YF in different species of neotropical primates after vaccination with the attenuated YFV 17DD strain. 24 neotropical primates belonging to the Belo Horizonte Zoo squad were selected, including four Saguinus imperator, five Lagothrix cana, five Sapajus xanthosternos, seven Alouatta guariba clamitans, one Pithecia irrorata, one Aotus infulatus and one Ateles sp. The animals were tracked based on clinical examination, blood count, biochemical profile, RT-PCR to detect RNAemia, detection of neutralizing antibodies by microPRNT and ELISA to assess seroconversion, in addition to behavioral analysis using a focal ethogram of the individuals. All individuals were considered suitable for vaccination and were inoculated with a single dose, varying in volume according to the size of the species. For 7 days after vaccination, the animals were monitored and had their behavior assessed again. On days 4, 60 post-immunization, clinical, hematological and biochemical evaluations, RNAemia, detection of IgG against the YF virus by ELISA and identification of seroneutralization were carried out. The vaccine did not produce clinical manifestations of YF in any of the primates. Within 60 days after vaccination, the animals seroconverted, with the production of neutralizing antibodies and IgG against YF, but individuals of the species L. cana, Ateles sp. and one S. imperator individual did not produce neutralizing antibodies. The present work demonstrated the safe and immunogenic profile of the existing vaccine against YF 17DD in howler monkeys, yellow-breasted capuchins, emperor tamarins, night monkeys and gray monkey saki. This knowledge can support further studies with other susceptible primate species and provide a possible solution for controlling epizootics and preventing the devastation of threatened species, being an important contribution to the conservation of threatened species, mainly ex situ.