Antibody Response to an Anti‐rabies Vaccine in a Dog Population under Field Conditions in Bolivia

Abstract

Rabies remains an important public health issue in Bolivia, South America. Public concern and fears are most focussed on dogs as the source of rabies. The objective of the present study was to assess immunity of an inactivated suckling mouse brain vaccine against canine rabies used for the official vaccination campaigns under field conditions in an endemic area of rabies in Bolivia. A total of 236 vaccinated and 44 unvaccinated dogs in Santa Cruz de la Sierra, selected using stratified random sampling, were investigated in order to obtain owned dog characteristics and antibody titres against rabies in April 2007. The proportion of vaccinated dogs with an antibody titre exceeded the protection threshold value of 0.5 EU/ml was 58% [95% confidence intervals (CI): 52-65], indicating that vaccination is likely to elicit an antibody response (odds ratio 6.3, 95% CI: 1.2-11.5). The range of geometric mean of antibody titre for vaccinated dogs (0.89 EU/ml; 95% CI: 0.75-1.04) was considered to meet the minimal acceptable level indicating an adequate immune response to the vaccine. However, the titre level was not satisfactory in comparison with the results from other field investigations with inactivated tissue culture vaccines. It is recommended for public health authorities to (1) consider modernizing their vaccine manufacturing method because the level of immunity induced by the current vaccine is comparably low, (2) conduct frequent vaccination campaigns to maintain high levels of vaccination coverage, and (3) actively manage the domestic dog population in the study area, which is largely responsible for rabies maintenance.

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

“…There were animals in other groups with past vaccination history who did not have adequate protection. Similar patterns of data had been observed by research groups in other countries as well [ 33 – 35 ]. However, Barth et al, indicates by analyzing many experimental results that dogs have a very high probability of survival after a later rabies infection, even if serum does not contain detectable anti-rabies antibodies irrespective of the period of time elapsed since the vaccination [ 18 ].…”

Rabies in the Eastern Cape Province of South Africa - where are we going wrong?

“…This could indicate that the dogs in Emalahleni do not seroconvert as efficiently as dogs that have better access to veterinary care. The geometric mean titre 30-60 days post-vaccination within this study (1.44 IU/ ) compares favourably with other studies 29,37,39 . However, as the number of vaccinations a dog had received before the study could not be verified, further interpretation of this result was not attempted.…”

“…In this study, 43 % of dogs whose owners reported previous vaccination had antibody titres of 0.5 IU/ or above. This response is lower than the percentage in other communities: a study in Spain found it to be 58 % 12 ; in urban Bolivia it was also found to be 58 % 39 ; in rural and peri-urban Kenya it was 48 % 23 and in urban Botswana 52 % 36 . Considering that the owner's responses regarding the vaccination status of their dogs could not be verified, it becomes difficult to evaluate the low proportion of dogs with adequate neutralising antibody titres in Emalahleni, but it may, amongst others, be attributable to: low vaccination coverage by AHTs in the preceding rabies campaign, a rapid drop in antibody titre after being vaccinated in the preceding campaign and/or incorrect handling and administration of vaccines during campaigns.…”

“…On the other hand, a study in a district in Kenya found that more than 50 % of the dog population was less than 1 year old 23 . The proportion of dogs aged less than 1 year is crucial in rabies eradication as this age group is very often unvaccinated 39 or shows a smaller proportion of seroconversion (≥0.5 IU/ ) than older dogs 37 . Moreover, only a small proportion (1 %) of dogs were reported to reach 10 years or more.…”

Incidence and Risk Factors associated with Rabies and Dog Bites among Dogs Involved in Bites in Plateau State, Nigera between 2011 and 2012

“…The disease still remains a very important public health problem in Nigeria posing serious fear to the populace (Suzuki et al, 2008), and about 10,000 annual human cases were reported in Nigeria (Nawathe, 1980). The disease has remained an endemic problem in Nigeria since it was first reported in 1912 (Umoh and Belino, 1978;Nawathe, 1980).…”