proper timing and proper administration
Description
Immunization through vaccination is a commonly used
method of reducing the risk (increased ID50) and consequence
(reduced pathogenicity) of bird or flock exposure to a disease-causing agent..
Vaccination is the practice of administering live and/or killed vaccines which have been modified to minimize
disease manifestation yet maximize immunity.
the primary purpose of immunization is to raise
the ID50 of the flock to prevent clinical disease following
subsequent challenge.
While some vaccines are given to protect
that individual bird against disease,
others are given to pass the
protection on to the next
generation, and others are given to prevent disease in the hen
and subsequent transmission of the disease to the chick
Vaccines and vaccine programs vary widely in their
effectiveness, and this is frequently by design. Some vaccines
are designed to incite high levels of immunity to protect birds
in the face of aggressive endemic disease challenges, such as
vvND.
These vaccines may cause a mild form of the
disease themselves but are deemed appropriate and
useful because of the risk associated with eventual infection of the
deadly field pathogen.
Vaccine selection and how they are programmed
frequently becomes an exercise in risk management and cost
efficiency.
Local conditions must always be
considered when evaluating and critiquing a
vaccination program.
A second reason for the vaccination
of poultry flocks is to hyper immunize hens to maximize
maternally derived antibody passed through the egg to the
hatching progeny.
Chicks frequently receive up to 3 weeks of protection from maternal anti-
bodies, allowing their immune system to mature to a level capable
of eliciting an efficient active immune response if exposed to a
potentially harmful virus or bacteria.
Antibodies are not always completely protective but for
viruses such as infectious bursal disease (IBD), many areas of the
world have found maternal antibodies a very useful tool in IBD
prevention and control.
The success of vaccination does not rest solely with the manufacturing or research of
vaccines. More important is the maintenance of the cold chain, protection of
the vaccine from the elements, and the correct application of the vaccine to the
bird.
vaccination programs should be documented
for each operation by the responsible veterinarian and
operations manager. All vaccines must be stored at the
correct temperature. Most vaccines require
refrigeration at 2°C to 8°C
Some vaccines, mostly killed oil
vaccines, can be safely stored at
room temperature. Some vaccines
need to be stored at temperatures
below 0°C..
Vaccines are adversely affected by
exposure to sunlight and heat. Vaccines must be administered
using suitably cleaned equipment and be given to every bird in
the defined epidemiological unit
Live vaccines are widely used throughout
the world because they are commonly effective when mass
applied, and they are relatively economical.
immunity from live vaccines is generally
short-lived, particularly following initial
exposure. Some exceptions to this exist for
vaccines such as for infectious laryngo-
tracheitis, fowl pox, and Marek’s disease,
which give long-lived immunity.
Inactivated vaccines or killed vaccines used in poultry are
generally whole bacteria or virus preparations combined with
an adjuvant that are designed for subcutaneous or intramuscular
injection
They are frequently, but not always, used in
commercial egg layer and breeding birds to
stimulate long lasting immunity and/or antibody levels to specific antigens.
Who this course is for:
- poultry farm owner,poultry science students,veterinarian,all interested in poultry farming
