Evaluación de la seroconversión como respuesta a la vacunación antirrábica en perros en el departamento del Valle del Cauca, Colombia, 2009

Abstract

Resultados. El 9,1 % de los perros de la muestra fueron seronegativos y el 25,1 % no evidenciaron respuesta inmunitaria humoral adecuada a la vacunación. La concentración de anticuerpos disminuyó gradualmente desde la aplicación de la vacuna, y estuvo asociada a edad y calidad de las vacunas, aunque no estuvo asociada a sexo ni a raza. Conclusiones. Con el fin de aumentar los porcentajes de perros seropositivos y con respuesta inmunitaria humoral adecuada, se hacen las siguientes recomendaciones: 1) utilizar vacunas antirrábicas viables; 2) aplicar dos dosis de vacuna durante los primeros seis meses de vida de los cachorros; 3) aplicar refuerzos de vacuna, por lo menos, una vez al año; 4) que las autoridades vigilen las actividades y los procesos programáticos relacionados con la vacunación antirrábica por particulares.Palabras clave: vacunas antirrábicas, virus de la rabia, Lyssavirus, zoonosis, vigilancia epidemiológica, inmunidad, Colombia. Evaluation of the seroconversion as a response to rabies vaccination in dogs, Valle del Cauca, Colombia, 2009Introduction. The province of Valle del Cauca has been free of dog rabies for more than 20 years. However, sylvatic rabies foci remain which are threats to the health of the populace and its pets. Rabies vaccination campaigns are carried out annually in all 42 counties of the province. Objectives. The impact of dog vaccination was evaluated on the basis of humoral immunoresponse, population parameters and correlation with variables inherent to the vaccination process and logistics. Materials and methods. Sera and associated data were obtained from each of the 42 counties for a total sample of 569 rabies-vaccinated dogs. Rabies neutralizing antibodies were measured by quantitative ELISA. The data were analyzed with the statistical programs in Epi-Info 6.0.Results. Nearly 10% of dogs were seronegative (9.1%) and an additional 25.1% did not elicit an adequate humoral immune response to vaccination. Concentration of rabies neutralizing antibodies diminished gradually with the time after vaccination and was correlated with dog age and vaccine quality. No associations were noted between dog gender or breed. Conclusions. These data permit the following recommendations: (1) only viable, non expired rabies vaccines must be used to immunize animals, (2) two doses of rabies vaccine must be applied during the first six months of dog life, (3) booster immunizations must be administered every year, (4) practices

Low level of the immune response against rabies virus in dogs and cats, a cross-sectional study in sheltered animals, Santander, Colombia

“…Notably, although 71.53% of the vaccinated dogs did not develop neutralizing humoral immunity, only 44.83% of the cats vaccinated in the mass vaccination campaigns of the second half of 2015 did not develop neutralizing antibodies. These results in dogs are far from the results reported by Paez et al (Páez et al 2011), who demonstrated that 74.9% of dogs had an adequate humoral immune response, that is, at levels equal to or higher than 0.5 IU/ml. In the case of cats, the present study is the first one in Colombia that shows the results of the anti-rabies immune response in cats in the country.…”

“…However, although the vaccination card was reviewed (data not shown), the information provided in these cards by the personnel responsible for vaccinations was inconsistent and incomplete and did not allow the evaluation of vaccine-related variables that could explain the low rate of seroconversion. This information could be confirmed in the study by (Páez et al 2011), demonstrating that there may be vaccines and/or batches that do not allow the production of effective antibody titers (Páez et al 2011). The differences found in the level of seroconversion among animal shelters (Fig.4) allow us to assume that there are anthropogenic variables that influence the immune response of vaccinated animals.…”

“…Rabies virus (RABV) belongs to the order Mononegavirales, family Rhabdoviridae, and genus Lyssavirus (Afonso et al 2016). Rabies transmission occurs in two epidemiological forms: a) urban, with the dog as the main reservoir and transmitter, and b) wild, with animals such as bats, foxes, and wolves as reservoirs and transmitters and cats as transmitters (Hampson et al 2009, Páez et al 2011.…”

“…The impact of failures in the cold chain of vaccines, inadequate handling of biologicals, inappropriate vaccine inoculation in canines, use of expired vaccines, or dishonesty of the persons or entities that sell the vaccines (Paéz et al 2007) has also been described. In Colombia, these problems have led to vaccine failures in which up to 35% of the vaccinated population does not develop an immune response or does so inadequately (Páez et al 2011).…”

Kinetics of rabies antibodies as a strategy for canine active immunization

“…The low concentration of antibody titers in dogs vaccinated against rabies has been previously reported [ 16 - 19 ]. Similarly, the immune response of dogs vaccinated only one time has already been evaluated and the results showed a rapid drop of antibody titers, which suggests that several animals are unprotected among vaccination campaigns [ 10 , 20 ].…”