Sero-prevalence of virus neutralizing antibodies for rabies in different groups of dogs following vaccination

Abstract

BackgroundMass vaccination of dogs is considered fundamental for national rabies control programmes in Sri Lanka, as dog is the main reservoir and transmitter of the disease.MethodsDogs were followed to determine the sero-prevalence of antibodies to the rabies virus. Altogether 510 previously vaccinated and unvaccinated dogs with owners (domestic dogs) and dogs without owners (stray dogs) of the local guard dog breed in different age groups recruited from Kalutara District, Sri Lanka. The dogs were vaccinated with a monovalent inactivated vaccine intramuscularly and serum antibody titres on days 0, 30, 180 and 360 were determined by the Rapid Fluorescent Focus Inhibition Test (RFFIT).ResultsThe results indicated, a single dose of anti-rabies vaccination fails to generate a protective level of immunity (0.5 IU/ml) which lasts until 1 year in 40.42% of dogs without owners and 57.14% of previously unvaccinated juvenile (age: 3 months to 1 year) dogs with owners. More than one vaccination would help to maintain antibody titres above the protective level in the majority of dogs. The pattern of antibody titre development in annually vaccinated and irregularly vaccinated (not annual) adult dogs with owners is closely similar irrespective of regularity in vaccination. Previously vaccinated animals have higher (2 IU/ml) antibody titres to begin with and have a higher antibody titre on day 360 too. They show a very good antibody titre by day 180. Unvaccinated animals start with low antibody titre and return to low titres by day 360, but have a satisfactory antibody titre by day 180.ConclusionsA single dose of anti-rabies vaccination is not sufficient for the maintenance of antibody titres for a period of 1 year in puppies, juvenile dogs with owners and in dogs without owners. Maternal antibodies do not provide adequate protection to puppies of previously vaccinated dams and puppies of previously unvaccinated dams. Immunity development after vaccination seems to be closely similar in both the groups of puppies.

Serological profiling of rabies antibodies by enzyme-linked immunosorbent assay and its comparative analysis with rapid fluorescent focus inhibition test in mouse model

“…Rabies virus is a neurotropic, negative sense, single-stranded RNA virus that belongs to the family Rhabdoviridae, genus Lyssavirus [ 1 ]. The causative virus can spread from saliva of infected animals to others through neuromuscular route [ 2 ]. It has been reported that around 55,000 human deaths occur due to rabies infection out of the millions exposed each year worldwide [ 3 ].…”

Investigation of protective level of rabies antibodies in vaccinated dogs in Chennai, India

“…This proportion is far higher than other reports from similar studies. [40][41][42] This is not only a concern for rabies control efforts in the canine population but also increases the risk of rabies in humans who may not seek post-exposure prophylaxis after a bite from a vaccinated dog. It is crucial that vaccines selected for use by the veterinary public sector and for mass dog vaccination campaigns are of high quality and retain potency until administration.…”

Modelling the challenges of managing free-ranging dog populations

“…At current levels of vaccine production and the financial resources committed, Wallace et al (2017) estimate a vaccine shortfall of 7.5 billion doses and a resource gap of US$ 3.9 billion to achieve global dog rabies elimination by 2030 (Wallace et al 2017). This analysis also does not take in to account that a substantial proportion of unowned dogs may fail to sero-convert to the required protective antibody levels with a single dose of vaccine (Pimburage et al 2017). It therefore becomes imperative to not lose focus on effective and long-term solutions to dog population management.…”

“…In the developing world, a large proportion of the dog population is mostly free-roaming; these dogs are quasiowned, never restrained nor subject to health or fertility control interventions. In such populations, there is a variation in antibody response to a single dose of anti-rabies vaccine, but most dogs do not have a protective antibody titer after a year (Pimburage et al 2017).…”