Immunogenicity, safety and tolerance of a purified duck embryo vaccine (PDEV, VAXIRAB) for rabies post-exposure prophylaxis: Results of a multicentric study in India

Modern biologics for rabies prophylaxis and the elimination of human cases mediated by dogs

Introduction: Rabies is a major viral zoonosis and neglected tropical disease, with a global distribution. Humans, domestic animals, and wild mammals are susceptible to infection. Etiological agents reside in the Order Mononegavirales, Family Rhabdoviridae, Genus Lyssavirus. This acute, progressive encephalitis causes the highest case fatality of any conventional infectious disease. Tens of millions of humans become exposed annually to the bites of infected mammals, predominantly in Asia and Africa. Despite the existence of effective vaccines and immune globulins, tens of thousands of people, typically children in the developing world, succumb. Areas covered: Concentrating upon both historical and major published references from the peer-reviewed literature over the past 5 years, we describe current biologics for rabies prevention, newly recommended principles for prophylaxis, and relevant future products in the developmental pipeline. Expert opinion: Modern human rabies biologics are pure, potent, safe, and efficacious, when used in a timely and appropriate manner. Few individuals survive after clinical signs. Anti-viral compounds are not licensed. Experimental therapy, while obviously desirable, is highly controversial. Education on bite prevention and integrated risk management are critical. Access to affordable care, dose-sparing, and shortened regimens of human rabies biologics remain key.

Current Status and Development of Vaccines and Other Biologics for Human Rabies Prevention

Rabies is a neglected viral zoonosis with the highest case fatality of any infectious disease. Pasteur's historical accomplishments during the late 19(th) century began the process of human vaccine development, continuing to evolve into the 21(st) century. Over the past 35 years, great improvements occurred in the production of potent tissue culture vaccines and the gradual removal from the market of unsafe nerve tissue products. Timely and appropriate administration of modern biologics virtually assures survivorship, even after severe exposures. Nevertheless, in the developing world, if not provided for free nationally, the cost of a single course of human prophylaxis exceeds the average monthly wage of the common worker. Beyond traditional approaches, recombinant, sub-unit and other novel methods are underway to improve the availability of safe, effective and more affordable rabies biologics.

Why we can prevent, control and possibly treat – but will not eradicate – rabies

ABSTRACT 

Rabies is an acute, progressive viral encephalitis. Despite historical recognition, millions still remain exposed annually. Most fatalities are of children, although this zoonosis is a vaccine-preventable disease. All developed countries interrupted canine transmission and increasingly, Asian and African communities recognize what Latin Americans demonstrated – dog rabies can be eliminated – by mass application of veterinary vaccines. Realistically, rabies is not a candidate for eradication. Management is lacking for major reservoirs, such as bats. Increasing pre-exposure immunization of individuals at risk, simplification of postexposure schedules, enhancing vaccine delivery by alternative routes, development of less expensive biologics and antiviral drugs, may lessen its impact if applied strategically in a One Health context.

Rabies vaccines: where do we stand, where are we heading?

Rabies being the most lethal zoonotic, vaccine-preventable viral disease with worldwide distribution of reservoir wild animals presents unique challenges for its diagnosis, management and control. Although vaccines available are highly effective, which had played the key role in controlling rabies in North America, western Europe and in a number of Asian and Latin American countries, the requirement of multiple doses along with boosters, associated cost to reduce the incidence in wild animals and prophylactic human vaccination has remained a major impediment towards achieving the same goals in poorer parts of the world such as sub-Saharan Africa and southeast Asia. Current efforts to contain rabies worldwide are directed towards the development of more safe, cheaper and efficacious vaccines along with anti-rabies antibodies for post-exposure prophylaxis. The work presented here provides an overview of the advances made towards controlling the human rabies, particularly in last 10 years, and future perspective.

Viral Vaccines in India: An Overview

Viruses cause a large number of diseases in humans, some of which are fatal, while others are highly debilitating. A majority of viral diseases attack infants and young children, while others strike people in their prime. Development of preventive measures against viral diseases is, therefore, of paramount importance. Vaccination is the most cost-effective medical intervention for preventing mortality and morbidity against infectious diseases. A number of effective and safe vaccines are currently available against several viral diseases of significant medical importance. Many of these manufactured in India, are at par with international standards and are affordable. For many other viral diseases, for which vaccines are currently not available, research is underway at various national laboratories, as well as in the private sector companies in India. The present overview highlights the various vaccine preventable viral diseases that are of special importance to India and aims to provide a glimpse of the various vaccines that are currently available, or are under development in India.