Letter to Editor
Vaccine and Vaccine Failures in Animals: Significance of Responsible Use of Vaccines
Ramya K1, Rani N1 and Sankar P2*
1Veterinary College and Research Institute, Namakkal-637002, Tamil Nadu, India
2Veterinary College and Research Institute, Orathanadu-614625, Tamil Nadu, India
*Corresponding author: Sankar Palanisamy, Veterinary College and Research Institute, Orathanadu-614625, Tamil Nadu, India, Tel: 7598343591; E-mail: drpsankarster@gmail.com
Article Information: Submission: 09/04/2017; Accepted: 21/04/2017; Published: 24/04/2017
Copyright: © 2017 Ramya K, et al. This is an open access article distributed under the Creative Commons Attribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Letter to Editor
The livestock industry is extremely important to the economy of
developing countries and includes not only commercial producers
of meat and milk, but also small producers with a few animals.
Producing and delivering wholesome food, and ensuring food safety
is the responsibility of every livestock producer, large or small.
Most commercial producers follow a quality assurance program
implementing a series of good production practices to ensure safe and
wholesome food production. Producers with only a few animals need
to follow the same standards. Healthy animals usually grow faster and
more efficiently. Healthy animals do not require treatment for health
problems, this removes the risk of drug residues and removes the cost
of treatment. It is cost effective to prevent disease rather than to treat
sick livestock.
Livestock are susceptible to a variety of diseases. One key to
keeping livestock healthy is by implementing a proper vaccination
program. Having a valid veterinary-client-patient relationship is
a key first step to understanding what is involved in developing a
vaccination program and in getting guidance if an animal becomes
ill. Veterinarians or local extension office can provide useful advice in
dealing with specific production practices. The purpose of a vaccine is
to provide exposure to a non-virulent (non-infective) form of a disease
agent before the animal is exposed to a natural infection. Vaccination
causes the animal to develop antibodies and cellular resistance that
protect against disease or infection. It is always preferable to prevent
disease rather than having to resort to treatment.
The consequences of disease may be transmission to other animals
or people, loss of efficiency through reduced animal growth, drop in milk production and death. Good husbandry, including efficient
bio-security measures, is the most important factor in prevention
of diseases in livestock. Nevertheless, animals can become ill and
highly infectious diseases can spread rapidly with devastating results.
Vaccines are an important part of the veterinarian’s toolbox.
How do Vaccines Work?:
Vaccines stimulate the body to produce its own defense against
infection. Mimicking what happens when an animal has been
exposed to disease, the body and its defensive system will “remember”
the identity of the invading organisms. So, when the animal comes
into contact with a disease, its body is ready to fight it and the animal
will not fall ill and suffer. This protects the individual animal and
because this animal will not develop the disease and will not become
infective, it will also help protect the population from the disease -
“herd immunity”.A vaccine may consist of live but attenuated viruses or bacteria, or
killed (inactivated) viruses or bacteria, or parts of them.
• “Killed” or inactivated vaccines are prepared from killed
organisms or fractions of the organism incapable of causing
disease. They generally provide a relatively short period of
immunity.
• In attenuated vaccines, the immunizing agent (antigen) is
an organism such as a virus, bacterium or parasite, which
has been developed to stimulate the production of the
appropriate antibodies without causing the disease. Live
vaccines are particularly effective in providing long-term protection, because they are a more powerful stimulus to the
immune system. They are also more versatile in their route of
administration.
• Biotechnology can provide vaccines for diseases which cannot
be controlled by conventional vaccine technology and create
more specific, better defined products with even greater safety
and efficacy.
Vaccination can be by a wide variety of routes: through water,
baits, air spray, eye inoculation, intranasally, orally or using the more
classical injection.
Achieving initial immunity may require more than one injection.
Once established, this can be boosted by subsequent vaccination,
as required. Modern vaccine research and technology means that
some vaccines can actively protect against a variety of diseases, in a
single product. These are called multivalent vaccines and using these
reduces the number of injections, broadens disease protection - and
helps reduce costs to the farmer.
Factors to be considered during Vaccination:
Vaccination is not a simple process that automatically produces
immunity. There are many reasons that vaccines can fail as noted
below;Animal factors:
• Immune status• Maternal protection (colostrum)
• Age
• Concurrent infection
• Vaccination
• Nutritional status
Environmental factors:
• Temperature• Air quality
• Feed/water access
• Density
• Seasonal influence
• Transport
Factors associated with pathogen:
• Exposure level• Virulence
• Survival outside host
• Transmission
• Wrong Serotype
• Potency and Purity
• Outdated Vaccine
Vaccine failure can occur due to many causes:
• Improper storage• Temperature
• Ultraviolet light
• Use after expiration
• Attenuated vaccines need to be used soon after mixing
• Insufficient time between vaccination and exposure
Improper administration:
• Dosage• Needle length and gauge
• Needle hygiene
• Syringe management
Improper mixing of vaccines:
• Different pH and diluentsImproper timing:
• Too early (maternal interference)• Too late (already in disease process)
Animal factors:
• Environmental stress• Transport
Even when a vaccine is administered properly and an immune
response occurs, it can fail to protect from disease.
Vaccine failure can be minimized by carefully handling and
administering the product:
• Keep vaccines refrigerated (not frozen).
• Keep vaccine out of direct sunlight.
• Be sure to use vaccines before expiration date.
• Vaccinate healthy animals, avoid vaccination of stressed
livestock.
• Follow all label directions on proper routes of administration
and injection site selection.
• Vaccines are administered with a repeating syringe and you
will need enough doses to vaccinate all animals, allow for
some waste and accidents.
• Keeping opened containers or reconstituted vaccines is not
recommended which may lead the vaccine to fail to achieve
protection and it could also cause illness due to the growth of
contaminants in reconstituted vaccines.
• In general, vaccines take 10-14 days to give protection.
Vaccination should be part of a herd or flock health program.
For vaccines to be most effective consider their use carefully in relation to the type of stock, season, previous property
history and disease incidence e.g. young animals should
be protected against the common and predictable diseases
before management events such as castration, shearing,
weaning and movement to new properties.
• To get the most out of your vaccines protect them from heat
or sunlight by keeping them in an Esky until required. Keep
vaccines and equipment away from dirt and dust, which can
contaminate equipment and introduce infection. Use a small
table to help keep vaccines and equipment clean and off the
ground.
• Do not mix different vaccines together. Combined vaccines
require a great deal of care in balancing the components.
However, if more than one vaccine is required use separate
syringes and administer them at different sites, at least 15 cm
apart and preferably on different sides of the animal’s body.
• If conducting tick fever vaccinations, do not give other
vaccinations at the same time. If it is unavoidable, use a separate syringe for each treatment and administer them on
opposite sides of the animal’s body. Ideally, other inoculations
should be performed either two weeks before or four weeks
after tick fever vaccination, particularly in adult animals,
which are more likely to react to the tick fever vaccine.
• Avoid carcase damage by administering the vaccine according
to label instructions and use the least commercially valuable
site on the animal, for example high on the neck behind the
ear.
• When vaccinating a herd, ensure a full dose of vaccine is
given to every animal. Check syringes carefully to ensure that
the correct dose is being delivered. Give the required booster
injection at the correct time to all animals that require it.
• Follow all label directions on vaccination of pregnant animals,
and age of animals at vaccination.
• In addition, it may be necessary to administer booster injections
if indicated on the label directions.
