Safety and immunogenicity of 17DD attenuated yellow fever vaccine in howler monkeys (Alouatta spp.).

BACKGROUND: Alouatta spp. are highly susceptible to yellow fever (YF) infection and develop an often fatal disease. The threat posed by an outbreak started in 2016 leads us to investigate vaccination as a potential tool in preventing YF in non-human primates (NHP). METHODS: Susceptible howler monkeys were immunized with three different concentrations of the human Brazilian commercial YF17DD vaccine. Post-vaccination viremia/RNAemia, immunogenicity, and safety were characterized. RESULTS: The vaccine did not produce YF clinical manifestations in any of the NHPs. After immunization, all animals seroconverted demonstrating the ability of the YF vaccine to induce humoral response in Alouatta species. CONCLUSIONS: The present work has demonstrated the safe and immunogenic profile of the existing YF 17DD vaccine in howler monkeys. This knowledge may support further studies with other susceptible monkey species and provide a possible solution for controlling epizootics and preventing the devastation of endangered species.

Detection of antibodies against flavivirus over time in wild non-human primates from the lowlands of Costa Rica.

Two-hundred-nine free ranging non-human primates from 31 locations throughout Costa Rica were captured and released between 1993 and 2012, and blood samples, sera or plasma were collected, to detect antigens and antibodies, and so assess the distribution of active and passive flavivirus infections over time. A competitive enzyme-linked immunoassay for the detection of antibodies was used to determine the distribution of past flavivirus infections over time, while Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) was used to detect active West Nile Virus (WNV) and Dengue virus (DENV) infections. The first serological evidence of flavivirus in these animals was determined in 1993, at the same time when DENV re-emerged in humans from Costa Rica. An increase in the number of seropositive wild monkeys to flavivirus was determined over time in the country (11.3% seropositivity in 1993-1996, 20.7% in 2001-2008, and finally 52.9% in 2010-2012). Furthermore, the presence of DENV2 was detected in samples from four howler monkeys collected in 2001-2002, whereas DENV2, DENV3, and DENV4 were found in samples from four white-faced monkeys, and WNV in three howler monkeys living in the Pacific coast of Costa Rica during 2010-2012. The habitat where the positive PCR individuals lived were characterized as fragmented forests, having temperatures ranging from 26°C to 28°C, altitudes below 250 meters above sea level, high precipitation during 7 to 9 months (1500-4000 mm), and a marked dry season of 3 to 5 months. All these animals were living near mangroves; however, they did not show clinical signs of illness at the time of sampling. Results obtained show that the number of seropositive wild non-human primates to flavivirus were increasing during time in the country, longitudinal studies are needed to investigate their role as sentinels of these viruses and to determine if flavivirus infections can affect these species.

Antibody immunoglobulin G (IgG) response to Alouattamyia baeri (Diptera:Cuterebridae) parasitism of howler monkeys, Alouatta palliata, in Panama.

Larval bot fly burdens and the presence of immunoglobulin G (IgG) antibodies to larval antigens of Alouattamyia baeri (Shannon & Greene) were determined in howler monkeys, Alouatta palliata authority, from Barro Colorado Island, Panama, during July and August of 1991 and 1992. Monkeys produced antibodies (IgG) to both 1st- and 3rd-instar proteins of the monkey bot as measured by an enzyme immunoassay. The response to 1st-instar antigen was correlated with number of bots for the 1991 data and for pooled data from 1991 and 1992. No correlation was observed for the response to 3rd instar antigen. First-instar extracts were composed of 9 major proteins as visualized by SDS-PAGE. Bands at 17, 25, and 32 kDa were positive in Western blots. Third-instar extracts contained at least 13 major bands, with those at 120 and 130 kDa reactive in immunoblots. The immune response to A. baeri may be involved in limiting larval bot numbers.