Immunogenicity and efficacy of non-adjuvant tissue culture-based rabies vaccine produced in Ethiopia

Rabies is 100% fatal, but it is preventable. More than 95% of human rabies cases occur in improperly treated individuals. This is partly due to the fact that modern post-exposure rabies prophylaxis is expensive and therefore not readily available in many endemic regions. Nervous tissue vaccine has been in use for more than 100yrs. These vaccines have now been superseded in purity, potency, immunogenicity and safety. The efficacy and immunogenicity of inactivated tissue culture rabies vaccine, produced in Ethiopia was evaluated. Twelve experimental dogs from local breed were duly conditioned during a quarantine period and assigned to two groups randomly. Animals in group I (cases) were vaccinated subcutaneously with 1 ml of our experimental vaccine. Dogs in group II served as non-vaccinated controls. The immune response of each dog was monitored for 90 days. On the day 90 after final sampling, all dogs were challenged in the masseter muscle with a rabies street virus of canine origin. To evaluate the titer of the rabies virus neutralizing antibodies (VNA), sera were analyzed by Fluorescent Antibody Virus Neutralization (FAVN) Test. Geometric Mean Titers (GMT) to rabies virus was determined at days 7, 15, 21, 30, 60 and 90. Geometric mean titers were equal to 1.59, 1.73, 2.19, 3.58, 3.17 and 3.35 IU/ml respectively. All dogs showed VNA titers higher than the 0.5 IU/ml mandated WHO recommended threshold. All vaccinated dogs, survived the challenge. In contrast, 83.3% of dogs in the control (non-vaccinated group), developed rabies and died. This study indicated that cell culture-based anti-rabies developed inhouse, with no adjuvant is efficacious and immunogenic

Estimating the Global Burden of Endemic Canine Rabies

Background Rabies is a notoriously underreported and neglected disease of low-income countries. This study aims to estimate the public health and economic burden of rabies circulating in domestic dog populations, globally and on a country-by-country basis, allowing an objective assessment of how much this preventable disease costs endemic countries. Methodology/Principal Findings We established relationships between rabies mortality and rabies prevention and control measures, which we incorporated into a model framework. We used data derived from extensive literature searches and questionnaires on disease incidence, control interventions and preventative measures within this framework to estimate the disease burden. The burden of rabies impacts on public health sector budgets, local communities and livestock economies, with the highest risk of rabies in the poorest regions of the world. This study estimates that globally canine rabies causes approximately 59,000 (95% Confidence Intervals: 25-159,000) human deaths, over 3.7 million (95% CIs: 1.6-10.4 million) disability-adjusted life years (DALYs) and 8.6 billion USD (95% CIs: 2.9-21.5 billion) economic losses annually. The largest component of the economic burden is due to premature death (55%), followed by direct costs of post-exposure prophylaxis (PEP, 20%) and lost income whilst seeking PEP (15.5%), with only limited costs to the veterinary sector due to dog vaccination (1.5%), and additional costs to communities from livestock losses (6%). Conclusions/Significance This study demonstrates that investment in dog vaccination, the single most effective way of reducing the disease burden, has been inadequate and that the availability and affordability of PEP needs improving. Collaborative investments by medical and veterinary sectors could dramatically reduce the current large, and unnecessary, burden of rabies on affected communities. Improved surveillance is needed to reduce uncertainty in burden estimates and to monitor the impacts of control efforts

Rabies re-emergence after long-term disease freedom (Amur Oblast, Russia)

Retrospective descriptive epizootological study was conducted in the Amur Oblast (Russian Far East), where a rabies outbreak was reported in 2018. The aim of the study was to analyze probable routes of rabies introduction and features of its spatial and temporal spread in the territory that remained free from this infection from 1972 to 2018. In 2018–2021, altogether 1,416 animals were examined for the infection with the rabies virus. Forty-seven animal rabies cases were confirmed; the proportion of wild animals (Vulpes vulpes, Nyctereutes procyonoides, Canis lupus) amounted to 66%. The first cases were detected within 30 km from the state border with China. Nucleotide sequences of the nucleoprotein gene of three rabies virus isolates were determined and their belonging to the Arctic-like-2 genetic lineage was established. Genetically closest rabies virus isolates have been found in Heilongjiang Province (China, 2011, 2018) and Jewish Autonomous Oblast (Russia, 1980). GIS and open Earth remote sensing data were used to map the rabies cases. After 2018, the epizootic spread within the forest-steppe landscapes of the Zeya-Bureya Plain, where human and animal rabies cases had been earlier reported (until 1972). The front of the epizootic spread in a north-eastern direction at an average speed of 59 (16–302) km during one epizootic cycle. The introduction of the rabies virus was most likely along the Amur River valley from downstream regions of Russia and China that are rabies infected