Dr K Rashbehari Singh
On the 27th April 2019 World Veterinary Day (WVD) 2019 will be celebrated globally on the theme, ‘Value of Vaccination’ and it is an opportunity to celebrate the contributions of veterinarians to the health of animals and society. The WVA (World Veterinary Association) will co-host the World Veterinary Day Award 2019 with HealthforAnimals, the global animal medicines association and the Award has increased to USD $ 2500. All WVA Veterinary Associations, who may submit evidence that demonstrate their support of the value of vaccination, can apply for the award.
A biological preparation that provides active acquired immunity to a particular disease is called a vaccine. A vaccine typically contains suspension of weekend, killed, or fragmented microorganisms or toxins or of antibodies or lymphocytes that is administered primarily to prevent disease. The administration of vaccines is called vaccination.
Veterinary vaccines are important for animal health, food production, animal welfare and public health. They are a cost-effective method to prevent animal disease, enhance efficiency of food production, and reduce or prevent transmission of zoonotic and foodborne infections to people.
In this modern society, effective and safe animal vaccines are essential. Without vaccines for prevention of epizootics (an epidemic outbreak of disease in an animal population, often with the implication that it may extend to humans) in food-producing animals, it would be impossible to produce enough animal protein to feed the nearly 7 billion people on earth. Again, without companion animal vaccines, especially rabies vaccine many people would not keep a pet in the household and would not experience the satisfaction of the human animal bond. Zoonotic diseases (infectious diseases that can be naturally transmitted between animals and humans) such as brucellosis and leptospirosis would be much more prevalent without effective vaccines.
New variants of existing pathogens and new diseases emerge every year, menacing human as well as animal health. These new pathogens and diseases cause public and animal health issues and to solve these issues, development of new vaccines is required. Vaccines offer one of the best, long- term solutions for effective prevention of existing and emerging infectious animal diseases today and in the future.
Both animal and human lives will be benefited from the continued progress in vaccine research and development. For this continued progress, a clear understanding of the benefits and risks associated with vaccines is needed amongst the regulatory authorities, researchers, industry, veterinarians, the media and the general public.
Seventy five (75) per cent of all new human pathogens originate from animal sources and therefore vaccines are key to limiting the spread of infectious diseases from animals to people in future.
Not only protecting companion animals and livestock against the infectious diseases, the vaccines ensure the provision of healthy and nutritious food such as eggs, milk and meat products. Without vaccination the picture of close association between people and their pets will be different. Vaccinations against the infectious diseases of food producing animals play a key role for efficient livestock production. Over 100 different veterinary vaccines are currently commercially available.
EXAMPLES OF IMPACT OF VETERINARY VACCINES
Rinderpest disease is an acute, highly contagious, viral disease of cattle, domesticated buffalo and some species of wildlife. This disease is a classic example of how an animal disease can have a large public health impact. Cattle infected with rinderpest were shipped to Africa in the year 1889 causing an epidemic that established the virus on the continent. Initially, approximately 90 per cent of the cattle died in the sub-Saharan Africa. Sheep, goat, wild buffalo, giraffe and wildebeest were also decimated. Draft animals, domestic livestock and wildlife were killed by the disease and that resulted in mass starvation, killing a third of the human population in Ethiopia and two-thirds of Maasai people of Tanzania. Thickets were formed in grasslands due to reduced number of grazing animals and these thickets served as breeding grounds for tsetse flies, the vector of trypanosomes, resulting in an outbreak of trypanosomiasis (African sleeping sickness) in humans. This epidemic of rinderpest disease is considered by some to have been the most catastrophic natural disaster ever to affect Africa. The Global Rinderpest Eradication Programme is a large scale international collaboration involving vaccination, local and international trade restrictions, and surveillance. This international collaboration may be one of the veterinary medicine’s greatest achievements and riderpest may soon become only the second disease, after smallpox, to be globally eradicated.
Rabies may be the oldest infectious disease known to man. Human rabies in developed countries have nearly eliminated due to vaccination of rabies vaccine in domestic animals and wildlife. Every year, it kills as many as 60,000 people worldwide, i.e. about 1 person dying of rabies every 9 minutes. Over 95 per cent of human rabies cases are caused by the bite of rabies infected dogs. Rabies in human can be eliminated by adequate animal vaccination, providing awareness to those at risk and appropriate medical care for those who are bitten.
ROLES OF VETERINARY VACCINES
According to the United Nations Department of Economic and Social Affairs Population Division world population was approximately 6.9 billion in 2010, and is estimated to increase to just to over 8.6 billion in 2030 and reach 9.8 billion in 2050. High–Level Expert Forum of the United Nations Food and Agricultural Organization (FAO) reported in October 2009 that in order to feed a projected world population, the overall food production will need to increase by 70 per cent between 2005/07 to 2050. In meeting this need, vaccines that preserve animal health and improve production are important components.
There is a major impact of vaccination for controlling zoonotic diseases in food animals, companion animals and wildlife on reducing the incidence of zoonotic diseases in people. It is unlikely that without rabies vaccines, families would be willing to keep cats and dogs as pets. Due to lack of available Brucella vaccines for animals, many countries have severe problems with Brucellosis in cattle, small ruminants, and people. However, vaccines of Brucellosis were instrumental in the eradication programme in the United States.
Human and animal health faces a growing threat of emerging and exotic animal diseases and jeopardizes food security. Environmental degradation, globalized trade and travel and increase in human and animal populations, enhance opportunities for transfer of pathogens within and between species. Increased demand for animal protein has resulted in intensified commercial food animal production and/or expanded backyard production, which present unique challenges for disease emergence and control. Outbreak of emerging zoonotic diseases of both food and companion animals will be inevitable in the coming decades. For controlling emerging diseases, rapid development of animal vaccines will play a key role.
With the extensive use of antibiotics in veterinary and human medicine, there is increasing concern related to antibiotic resistance. The need for antibiotics to treat infections in food producing and companion animals can be reduced by proper use of veterinary vaccines. Affordable and available vaccines reduce dependence on antibiotics for animal health.
VACCINE PRODUCTION
There is need of coordinated approach for animal and human infectious disease experts to prepare vaccines for new and emerging diseases. Veterinary vaccines must be pure, safe, potent, effective and economical. For ensuring quality vaccine production for animal disease control, proper standards and production controls in the manufacture of veterinary vaccines are essential. Low and affordable cost of animal vaccines will encourage more use of vaccines and less use of antibiotics.
CONCLUSION
Livestock and poultry play important roles in providing healthy and nutritious food and livelihoods to the farmers. New human and animal diseases will continue to emerge in future. To face the challenge, there is need for coordinated approach of the health, veterinary and public health communities at local and global levels. Readily accessible and economic production of veterinary vaccines will play a key role for protection of human and animal health, food safety and food security.
To ensure access to critically important veterinary vaccines for current and future disease control needs, awareness campaigns about the recent trends of vaccines and vaccination are required. Legislative support and conducive policy development will help to stimulate public and private investment for vaccine production. Availability of funding, continued investment and collaboration of different stakeholders will help in the development of new vaccines to face the emerging and challenging animal diseases.
The writer is retired Deputy Director (Extension Education), Central Agricultural University, Lamphelpat, Imphal and can be reached at
[email protected]