Failure of vaccination in poultry

FAILURE OF VACCINATION IN
POULTRY
BY: DR. SAROJ KUMAR
Technical Consultant
Bihar kosi basin development project
Animal &Fisheries Resources Department ,
Govt.of Bihar

Introduction
 Protecting bird against diseases is more than just
providing them with preventive vaccine.
 Diseases prevention is complex multifactor issue.
 Vaccine are often blame for insufficient protection
but in fact there are many other causes for
vaccination failure

Avian Immune System
 A basic understanding of avian immune system is
critical and essential to vaccination.
 It is divided in two system :
 A: Non specific immune system (Innate
Immunity).
 B: Specific immune system (Passive immunity).

Non specific immune system
(Innate Immunity).
 This system include :-
 Body temperature.
 Body feature.
 Normal micro flora.
 Respiratory tract.
 Other factor- Age, nutrition pH etc.

Specific immune system.
 Bird pass an antibody through the yolk.
 The half life of chicken antibody from the hen
range from 3 to 5 days. With protective immunity
level persisting for up to three weeks.

Vaccine
 Vaccine is suspension of micro organism either
live or inactivated when administrated in to the
body produce immunity against the specific
disease.
 Type of vaccine.
1. Live
2. Killed

Why vaccination ?
 Vaccine are used to prevent or reduce problem
that can occurs when a poultry flock is exposed
to field disease organism.
 The primary strategy for controlling disease
should not be vaccination but measure to prevent
the disease from entering premises.
 Vaccination can be the next line of defense when
the disease occasionally brench the premises
due to failure in boisecuritys

Vaccination failures
 Vaccination failures should be referred to as
immunological failure( i.e vaccination did not
stimulate the bird immune system.) hence the
birds did not receive the vaccine.
 When vaccination failure the natural tendency is
to blame the vaccination .But there are many
other factor that must be evaluate to determine
the cause of failure.
 Vaccine are not effective if they are do not get
into the birds the right way at the right time.

Factors causing vaccination failures
 Maternal antibodies
 Stress
 Vaccination programme
 Improper delivery/handling
 Immunosuppression
 Management practices
 Vaccine quality
 Poor administration
 Vaccine strain/serotype.
 Proper cold chain maintenance.

Maternal antibodies
 The immune status of the breeder flocks also can
be involved in a vaccine failure.
 If the breeder flock provides progeny with high
levels of maternal antibodies, it may interfere with
the multiplication of live vaccines, reducing the
amount of immunity produced.

Stress
 Vaccination itself is a stress. Stress may reduce
the chicken’s ability to mount an immune
response.
 Stress could include environmental extremes
(temperature, relative humidity), inadequate
nutrition, parasitism and other diseases.
 Vaccination of sick birds not only interferes with
the response to vaccination but also interferes
with the birds’ ability to overcome the disease
challenge present.

Immunosuppression
 Immunsuppression is the functional capacity of
the body to respond effectively against an antigen
and vaccine.thus it is directly related to the
immune status of birds receiving the vaccine.
 Birds may be immunosuppressed due to infection
with IBD, CIA or Marek’s disease viruses or from
consumption of feed with high levels of
mycotoxins,poor nutrition i.e deficiency of amino
acids,vitamins,and minerals.
 This may result in the development of limited
protection from the vaccination and an excessive
vaccine reaction with morbidity and mortality

Vaccination programme
 We all know that no one internationally effective
vaccination programme can be designed.
 Certain regions with a long history of poultry
production may require a programme with
repeated vaccinations against numerous different
pathogenic agents.

 But new poultry farms, geographically isolated
from other poultry operations, may have the
opportunity to decrease the costs of production
with a more limited vaccination programme.
 If the vaccination programme is not well studied
and executed it can harm rather than assist the
birds. If it is not known what diseases are
prevalent in the region, you may be infecting the
birds with an unnecessary virus when vaccinated.

Improper delivery/handling
 A well degined vaccination programe will not be
effective if the vaccine is damaged by improper
handling prior to administration.
 Live vaccines may become inactivated due to
improper handling.
 Store and handle vaccines as recommended by
the manufacturer.
 Eg. I.B vaccine lose 50% of its potency in warm
condition under one hours.

Management practices
 Management measures play an important role in
vaccine failures.
 There is no substitute for good management.
Vaccines should be used as part of a good
management programme,not as a replacement

Vaccine quality
 Usually if a vaccine fails to stimulate the
generation of sufficient antibody titers or when a
disease outbreak occurs, the first thing crosses
everybody’s mind is that the vaccine is of poor
quality.
 Vaccine quality is affected :if the wronge strain of
org. is used.if the specific dilutent is not used for
vaccine reconstitute.if imoroper host system is
used for vaccine production.

Poor administration
 Poor administration is the most common cause of
vaccine failure in poultry. Planning and attention
to details resulting in better administration that will
improve disease control and therefore
performance of poultry.
 Poor distribution of live vaccine administered by
the water or spray route may result in chickens
being “missed” in parts of the house.

 Live vaccines administered in the drinking water can
be destroyed before they reach the bird if water
sanitisers have not been removed from the water prior
to the addition of vaccine.

Vaccine strain/serotype
 Many infectious agents have several different
strains/serotypes.
 The vaccine may not contain the proper strains
or serotypes of organism required to stimulate
protective immunity against the agent causing the
field challenge
 Although the vaccine is administered properly
and uniform/adequate antibody titers are present,
the chickens still break with the disease,
particularly with IBD.

Cold chain maintenance
 It is the most important factor responsible for
vaccine failure.
 All live vaccine have to remain at 2-8˚C and
hence should be stored at this temp to
manufacture of vaccine until the administration to
the birds
 The vial of vaccine should kept in a bowl and
surrounded on all sides by ice.

How to prevent vaccine failure
:
 Always buy vaccines from a reliable source.
 Proper maintain cold chain. store at a
temperature recommended by a manufacturer.
 Only healthy birds should be vaccinated
according to the standard schedule.
 Feed should be analyzed from time to time for the
presence mycotoxins and other chemicals.
 Vaccination should be done in cool time of the
day.
 If chances of immunosupression use
immunomodulator it promote immune response of
birds.
 If we take all necessary precautions prior,during

Conclusion :
 Vaccines administered properly, at the correct time
and with the appropriate antigen content do not
guarantee 100 % and there is great need for
continuous evaluation .
 Vaccination may only be employed as a mean of
minimizing the economic impact of disease rather
than total prevention in 100% of the flock.
 However a well-designed,well-timed well vaccination
programme with good management ,nutrition and
biosecurity will go a long way to helping maintain a
healthy and productive flocks.

Failure of vaccination in poultry

Failure of vaccination in poultry

More Related Content

What's hot

Similar to Failure of vaccination in poultry

Recently uploaded

Failure of vaccination in poultry