Comparison of Immune Responses following Intradermal and Intramuscular Rabies Vaccination Methods

Abstract

INTRODUCTION Rabies is a zoonotic viral disease caused by a neurotropic virus. The virus has a non-segmented, singlestranded, negative-sense RNA genome and belongs to the genus Lyssavirus (Family: Rhabdoviridae) [1]. It is primarily transmitted to humans via the saliva of rabid animals after bite. Scratching or licking of mucous or wounds by rabid animals are the other routes of transmission [2, 3]. Unusual transmissions, such as solid organ transplantation and inhalation of contaminated aerosol (e.g., in bat-infested caves), have also been reported in some human rabies cases [3]. The disease is almost 100% fatal within two weeks following the appearance of clinical signs [4-6]. Annually, Rabies is responsible for 59000 human deaths, and over 3.7 million disability-adjusted life years (DALYs) lost. Children less than 15 years of age constitute almost 40% of exposures to suspected rabid animals [4]. Epidemiology. The rabies virus can infect humans, domestic, and wild animals, and has a significant impact on public health and the husbandry economy, especially in endemic regions [5-9]. The virus occurs across all parts of the world except Antarctica (Fig. 1) [10]. Approximately 20,000 human cases, which account for about one-third of annual rabies cases, occur in India, mostly through canine bites. Thus, in this country, the primary control measure has focused on the elimination of rabies in animals, mainly dogs [11]. A study in 2016, showed that rabies in many regions of China is still endemic and remains uncontrolled. In the northwest of China, rabies transmission to humans commonly occurs through the bite of stray dogs and foxes, and licensed vaccines for wildlife and large domestic animals are still required [12]. In Kazakhstan, despite mass animal vaccination, the disease is also endemic, causing substantial economic costs [13]. Sultanov et al. suggested that regular annual vaccination of domestic animals would be beneficial for the control of the disease [13]. In Ethiopia, where the canines are the primary vectors, about 2,700 annual human deaths occur due to rabies [13]. The annual cost of livestock loss due to rabies infection exceeds 50 million dollars in this country [14]. In Cambodia, Rabies has a high prevalence, especially in rural areas. Circulation of the virus among stray dogs in this country makes mass vaccination of these animals necessary [15]. Rabies is a zoonotic viral disease. The causative agent is a negative-sense RNA genome virus of the genus Lyssavirus (Family: Rhabdoviridae). The disease, commonly transmitted by rabid dogs, is the cause of mortality of over 59000 humans worldwide annually. This disease can be prevented before the development of symptoms through proper vaccination even after exposure. Hence, improvement of the vaccination schedule in the countries where rabies is endemic is essential. In addition to the type of vaccine, injection routes also contribute to enhanced immune responses and increased potency of the vaccines. The vaccines approved by the World Health Organization ...

Investigating Possible Etiologies of Post-Exposure Prophylaxis Failure and Deaths From Rabies Infection: Case Reports

“…This study investigated all suspected or confirmed cases of rabies despite PEP, based on the protocol provided by the Iranian Center for Disease Control (CDC) [7] from January 2014 to December 2018. In total, 29 deaths due to rabies were recorded in the study period.…”

Epidemiologic Aspects of Animal Bite, Rabies, and Predictors of Delay in Post-exposure Prophylaxis: A National Registry-based Study in Iran

“…Factors such as the type of vaccine and route of injection including intradermal, intramuscular, or subcutaneous are associated with the immune responses. 8 Most Asian countries with a high rabies burden produced or imported nerve-tissue vaccines to provide PEP in public hospitals. Therefore, the introduction of intradermal vaccination was necessary due to its cost-effectiveness.…”