dossier vaccination: what causes poultry vaccination to fail

Vaccination Failure

Contents

1. Types Of Vaccines2. Method Of Vaccination3. Causes Of Vaccination Failure4. Seological Monitoring

TYPES OF VACCINES

A live-type poultry vaccine

Types of VaccinesA live-type poultry vaccine

It contains a virus or bacteria that must infect the chicken and multiply in its body to produce immunity, preferably with minimal reaction.

This multiplication of the virus in the chicken is necessary because only relatively small amounts of virus are administered to the bird.

By multiplying in the chicken, increased amounts of virus are recognized by the chicken's immune system, thus an enhanced immune response results


Advantages of live-type vaccines are:1. Ease of administration.2. Low price.3. Rapid onset of immunity.4. Broader scope of protection because chickens are exposed to

all stages of the replicating virus.


Disadvantages of live-type vaccines are: :1. Problems with uniform vaccine application.2. Excessive vaccine reactions.3. Unwanted spread of the vaccine virus to neighboring poultry

houses.4. Extreme handling requirements needed to maintain viability

of the vaccine organism.

A killed-type poultry vaccine

Types of VaccinesA killed-type poultry vaccine

A killed-type poultry vaccine is prepared from bacteria or viruses that have been inactivated and processed, thus will not spread from bird-to-bird, and requires individual injection.

Killed vaccines are usually combined with an adjuvant such as aluminum hydroxide or an oil.

Adjuvants enhance the immune response by increasing the stability of the vaccine in the body, which then stimulates the immune system for a longer period of time.


Advantages of killed-type vaccines are:1. Assurance of administration of a uniform dose (birds are

individually injected)2. Safety (the organism has been inactivated)3. Development of uniform levels of immunity (each bird

receives the same dose)4. No chance for spread of vaccine organism to neighboring

poultry farms5. Increased product stability, and a choice of a wider variety of

virus strains.


Disadvantages of killed-type vaccines are:1. Increased costs (labor and product).2. Slower onset of immunity.3. Narrower spectrum of protection.4. Presence of localized tissue damage at site of injection due to

reaction with the adjuvant.

METHODS OF VACCINE APPLICATION

Methods of Vaccine-Application

• Individual application1. Eye drop2. Beak dipping3. Injection4. Wing web

• Mass application1. Spray 2. Drinking water

Road Map

Use only specific diluent

Very efficient

Highly labour intensive

Good Practice of Eye-Drop Vaccination

Prepare the vaccine suspension with the appropriate diluent.

Use the calibrated dropper (1,000 doses in 30 ml).

20 minutes for 1,000 birds. Hold the bottle in upside down position

and apply one drop per bird onto the eye or into the nasal duct.

Good Practice of Eye-Drop Vaccination

Avoid bottle contact with mucosa of eye or nostrils.

Compulsory route of vaccination for e.g. ILT, Mg.

Simultaneous vaccination with inactivated vaccines is possible.




Road Map

Use only specific diluent

Very efficient

Highly labour intensive

Good Practice of Beak-Dipping Vaccination

Prepare the vaccine suspension with distilled water.

Use about 150 - 200 ml per 1,000 chicks. Dip the beak of each bird up to the nostrils.

Good Practice of Beak-Dipping Vaccination

Advantages:1. Fast and easy vaccination during the first

days of life.2. All birds can be immunized.3. Avoids problems with irregular water

consumption.4. Avoids respiratory reactions as seen after

spray vaccination.5. Simultaneous vaccination with inactivated

vaccines is possible.




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Very efficient Highly labour intensive

Use only sterile equipment

Correct

Incorrect

Intramuscular & Subcutaneous Vaccination

Good Practice of Intramuscular & Subcutaneous Vaccination1. Use sterile equipment only. 2. Change needle every 800 birds.3. Dilute live vaccines in their appropriate diluent.4. Oil vaccines should have room-temperature before

application.5. Needle diameter:

1. 1,2 mm = 18 G; Length of 0,7 cm for s.c. 2. 1,0 - 1,3 cm for i.m.

6. Subcutaneous route: Inject into the lower part of the neck.7. Intramuscular route: Inject tangential into the breast muscle.




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Factors affecting water and spray vaccination

Bird1. Immunocompetence2. Water consumption3. Maternal antibodies4. Drinker space5. Ambient temperature

Vaccine1. Virus stability in water2. Lateral spread of vaccine

virus3. Immunogenicity of vaccine4. Vaccination timing5. Virus concentration in water

Factors affecting water and spray vaccination

Water vaccination1. Volume2. Time of water withdrawal3. Water quality4. Type of drinker5. Method of delivery

Spray vaccination1. Volume2. Particle size3. Relative humidity4. House design5. Distribution of spray6. Uniformity of droplets

Spray Vaccination

Spray vaccination

Rapid

Good immune response

Post vaccinal reactions

Use distilled water only

Good Practice of Spray Vaccination

Two methods of spray vaccination:(not suitable for diseased and Mg positive birds)1. Coarse spray:

• Droplet-size: 70 - 150 μ.• Recommended during the first 3 weeks of age

and for first vaccination.2. Fine spray:

• Droplet-size: 15 - 50 μ.• Reserved for ND booster-vaccination.


1. Select correct spray equipment.2. Spray equipment has to be clean, free from disinfectants and used for this

purpose only.3. Equipment has to be well maintained and adjusted.4. Use distilled water for preparing the vaccine solution.5. Darken the animal house and turn off ventilation during vaccination and

up to 30 minutes after vaccination.6. Gather the birds calmly in a restricted area, if necessary.7. Walk slowly through the animal house during vaccination (~ 20 minutes).8. Spray in direction to the heads of the chicken.9. Distribute the vaccine evenly.10.Hatchery: Spray 3 seconds on each box of 100 chicks.


Quantity of water needed is related to:1. Number and age of chicken.2. Equipment to be used.3. Ambient conditions: temperature & humidity (rate of

evaporation).4. All chicks have to be hit by the spray (shake the head for a

moment).5. All chicks heads have to get slightly moist.6. Vaccination in two applications might be necessary.7. Perform a sham vaccination in order to assess time and

volume of water needed!

Spray Vaccination:

The following table gives some examples:

Vaccination with coarse mist Vaccination with fine mist

Mean size of the drops > 50 μm < 50 μm

Flow/ pressure 500–600 ml/min. 2–3 bar 50 ml/min.

Vol./1000 birds 500–1000 ml 100–200 ml

Duration of spraying for 1000 birds 1–2 min. 5 min.




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Drinking Water Vaccination

Drinking water vaccination

Rapid Easy

Safe Economic

No disinfectants

Control water quality

Control water system and drinker

Drinking-Water Vaccination

Good Practice of Drinking-Water Vaccination Discontinue the drinking-water disinfection at least 3 days

before vaccination. Clean tanks, tubes and drinkers / nipples one day before

vaccination with clean water; don’t use soap or disinfectant. Dosing pumps are not preferred, but if they are used, use a

separate pump which is used for vaccinations only. For preparing the water-vaccine mixture, use only clean

plastic buckets and tools, which must not be used for other purposes.


Determine the volume of water needed for a 2 h uptake:The volume of water varies and is mainly influenced by: 1. Number of chicken2. Breed3. Age4. Temperature5. Feed


Carry out a test vaccination one day before without vaccine but with skimmed milk powder in order to:

1. Ascertain the adequate time of water deprivation (1-2h).2. Assess the water consumption during 2h.3. Skimmed milk powder binds residual disinfectants in the

tube system (“dead volumes”) and minerals.


Preparing the drinker system for vaccination:Before and during water deprivation (preferably in the morning)-1. Ensure a sufficient amount of drinker or nipples.2. Cut off the water supply.3. Empty and drain off completely the whole drinker system.4. Be aware of “dead volumes”.


Preparing the water-vaccine mixture:1. Use correct number of vaccine-doses. Never under dose.2. Prepare the water-vaccine mixture on a clean desk in a clean

room, using a clean plastic bucket and tools.3. Use only clean water of very good quality, e.g. mineral water,

for dissolving the vaccine (small volume).4. Add 0,2-0,25 % (2-2,5g/l) skimmed milk powder to the required

volume of clean water of good quality (pH ~6, no bacteria, no chlorine, no metallic ions, no disinfectants) and mix well.

5. Mix well vaccine solution with the milky water by means of a plastic stirrer.


Perform drinking-water vaccination after water deprivation:1. Fill and drain the whole drinker system with the milky water-

vaccine mixture.2. Make sure that milky water-vaccine mixture or dye arrives at

each drinker, nipple and the end of tubes.3. Make sure that all birds drink the water-vaccine solution by

going slowly through the chicken house.4. After complete consumption of the water-vaccine mixture in

about 2h, refill the drinker system with clean water of good quality at its maximum and add skimmed milk powder.


Bell drinker: 1 / 80-100 birds

Nipple drinker: 1 / 10-15 birds

Cup drinker: 1 / 25-30 birds

Troughs 6’: 1 / 150 birdsTroughs 8’: 1 / 200 birds

Quality of drinking water according to EU norms:

Parameter: Norms for Human Acceptable for poultry

pH 6,5 – 8,5 (max. 9,5)

Hardness 15°-30°(= 150 – 300 ppm Ca)

Organic matter < 5 mg / liter

Nitrate (NO 3) < 50 mg / liter

Nitrite (NO 2) < 0,1 mg / liter

Ammonium (NH 4) < 0,5 mg / liter

Chlorine (Cl) < 200 mg / liter

Iron (Fe) < 0,2 mg / liter

Total germs < 10 colonies / 1 ml < 10 colonies / 100 ml

Total coliform bact. 0 < 5 / 100 ml

Total fecal coliform bact. 0 < 5 / 100 ml

Fecal Streptococci 0 < 5 / 100 ml

Clostridium spp 0 < 10 / 100 ml

Staphylococci 0 0

Salmonella 0 0

Problem Effect Corrective Measurement

Excessive time for vaccine solution to reach all birds

Vaccine titer may drop below immunizing level

Drain residual water and fill water system with vaccine under pressure (with dye)

Excessive residual water in lines

Delayed delivery of vaccine to birds at the end of waterlines

Fill water system with vaccine (using dye) while simultaneously draining residual water

Vaccine solution consumed in less than 1,5-2 hours

Vaccine consumed by dominant birds only, too many unvaccinated remain

Increase volume of vaccine stock solution

Uneven application of vaccine Decrease water withdrawal

Problem Effect Corrective Measurement

Correct volume of vaccine solution consumed in more than 2 hours

Vaccine titer may drop below immunizing level

Split vaccination into two successive vaccinations (50% + 50%)

Airlocks Delayed delivery of vaccine to areas / tiers in the house

Fill waterlines with vaccine (with dye) while draining residual water

Uneven vaccination of flock

Fill waterlines with vaccine before light comes in the morning

Birds at back of battery, last cages do not receive vaccine

Vaccine volume not enough to fill water system

Increase volume of vaccine solution

Uneven vaccination of cage row

Drain residual water. Turn off lights while filling waterlines with vaccine

Vaccination Failure

GoodVaccination

ProgramDesign

Basics of Vaccination in PoultryElements of a Vaccination Program

Interval betweenSubsequent vaccinations

Route of vaccination

Age of the first vaccination Type of vaccines

Number of vaccinations

1. Stimulation & maintenance of protective immunity2. Development of immunologic memory

GoodImmune Response

Basics of Vaccination in PoultryRequirements for Good Immune Response

No immune suppression

Healthy birds

Good administration technique

Correct vaccination programme

Good nutrition Correct vaccine storage

Correct vaccine

No stress

What Is Vaccination Failure?

A vaccination failure occurs when, following vaccine administration:The chickens do not develop adequate antibody titer levels. and/or The chickens are susceptible to a field disease outbreak.

What Is Vaccination Failure?

When a vaccination fails, the natural inclination is to blame the vaccine, although there are other factors that must be evaluated to determine the cause of the failure.

Vaccination Failure - Bird

Causes Of Vaccination Failure / Bird

• Maternal antibodies• Stress• Chickens may already be incubating

the disease• Chickens may be immunosuppressed• Strong field challenge• Weaning of vaccine immunity

Road Map

Maternal Antibodies

A high level of maternal antibodies in the young chicken may interfere with the multiplication of live vaccines, reducing the amount of immunity produced.

Maternal Antibodies

For example, If a chick comes from a breeder hen with high levels of antibody against Gumboro (Infectious Bursal Disease), the chick will typically have high levels of antibodies (maternal) for several weeks. If vaccination is attempted in the presence of these antibodies, some of the vaccine virus will be inactivated.




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Stress

Stress may reduce the chicken's ability to mount an immune response. Stress may include:1. Environmental extremes (temperature, relative humidity)2. Inadequate nutrition3. Parasitism4. Other diseases.

Chickens should not be vaccinated during periods of stress, so it is better to delay vaccination until birds are healthy.




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Chickens May Already Be Incubating The Disease

Chickens may already be incubating the disease at the time of vaccine administration.

Despite proper administration, birds become diseased because time is needed for antibody production to begin and reach protective levels.

Chickens May Already Be Incubating The Disease

Remember, after first exposure to a live virus-type vaccine, immunoglobulins G, M, and A are first detected approximately 4 to 5 days following exposure.

Additional days are required for titers to reach protective levels.




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Chickens May Be Immunosuppressed

Chickens may be immunosuppressed due to infection with IBD virus or Mareks' disease virus, or from consumption of feed with high levels of mycotoxins.

The term immunosuppression refers to circumstances where the non-cellular (antibody) and cellular components of the immune system are not functioning properly.

This may result in the development of only limited protection from the vaccination and an excessive vaccine reaction with morbidity and mortality




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Strong Field Challenge

No vaccine can tolerate unlimited field challenge




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Weaning Of Vaccine Immunity

Antibodies are protein, subjected to metabolic breakdown.

Vaccination Failure - Vaccine

Causes Of Vaccination Failure / Vaccine

• Live vaccines may be inactivated• The vaccine may not contain the

proper strains• Poor distribution of live vaccine• Vaccine may be of poor quality

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Live Vaccines May Be Inactivated

Live vaccines may be inactivated due to improper handling or administration.

Before administering live vaccines, check and record lot numbers and expiration dates on the vials.

Store and handle vaccines as recommended by the manufacturer.

Once a vaccine is reconstituted, the "time clock is ticking." Infectious bronchitis vaccine loses 50 percent of its potency in warm conditions in under 1 hour




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The Vaccine May Not Contain The Proper Strains

The vaccine may not contain the proper strains or serotypes of organism required to stimulate protective immunity.

Although the vaccine is administered properly and uniform and adequate antibody titers are present, the chickens still break with the disease, particularly with infectious bronchitis and more recently with infectious bursal disease.




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Poor Distribution Of Live Vaccine

Poor distribution of live vaccine administered by the water or spray route may result in chickens being "missed" in parts of the house.

Relying on transmission of the vaccine from bird to bird is risky, and can result in excessive rolling-type reactions of long duration and delayed immunity in the flock.

"Misses" with killed vaccines will result in chickens with no protection, as killed vaccines will not spread from bird to bird




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Vaccine May Be Of Poor Quality

Vaccine may be of poor quality (low vaccine titer, contaminated, etc.).

The vaccine manufacturing industry is highly regulated and has extensive internal quality control.

Vaccine failure due to problems with the vaccine are rare.

VACCINATIONSEROLOGICAL MONITORING

Most Important Serological Tests

1. Hemagglutination Inhibition test (HI).

2. ELISA.

3. Rapid plate agglutination test (RPA).

4. Agar gel precipitation test (AGPT).

Most Important Serological Tests

When Conducting Serological monitoring has to know 2 basically things:- 1. What result to expect prior to testing? (Set standards for

successful vaccination)2. What action to take if results are not according expectation?

ELISA

Interpretation of vaccination results by ELISA is usually done by evaluating the 3 main key components of immune response after vaccination, which are:-

Intensity of Response (Mean Titer).

Do birds develop sufficient titer levels that are in the expected range for the used vaccine?

These expected titers following vaccination are often called “Baseline Titers”

These Baseline titer values may vary according to type of bird, age, vaccine type, vaccination program and other factors.

Therefore, one should make their own baselines for there own vaccination programs and local conditions.

Uniformity of Response (CV%)

Is the vaccine actually getting to the all birds or not. The general guidelines for % CV following vaccination are as

follows:-

% CV Uniformity Less than 30 % Excellent From 30-50 % Good Greater than 50 % Need to Improve

Persistency of Response (Mean Titer response over Time)

Do titers persist long enough over time, or is another vaccination needed to boost titers above minimum protective levels.

Test Vaccine Type Mean titer range at 35 - 40 days

Suspect Titer Infection

NDV-Live, 2x D.W 2000 – 5000 More than 7,000

-Live, 2x Spray 4000 – 8000 More than 10,000

IBV-Live, 1x (H120) 800 – 1500 More than 3,000

-Live, 2x (H120) 2000 – 4000 More than 6,000

IBD -Live, 1x (intmed.) 2500 – 4500 More than 7,000

-Live, 2x (intmed.) 3000 – 6500 More than 9,000

Vaccination Baselines Titers in Broiler

Test Vaccine Type Mean titer range Wks after Vac. To test

NDV-Live (Lasota) 2,000 – 8,000 2 – 3 wks -Inact. 10,000 – 15,000 4 – 7 wks

IBV-Live (H120) 2,000 – 4,000 3 – 5 wks-Inact. 6,000 – 17,000 5 – 7 wks

IBD -Live (intmed.) 2,500 – 7,000 3 –5 wks -Inact. 7,000 – 12,000 4 – 7 wks

Vaccination Baselines Titers in layers or Breeders:-

dossier vaccination: what causes poultry vaccination to fail

Health & Medicine

methods of vaccine

vaccine virus

killedtype poultry vaccine

livetype poultry vaccine

vaccine organism

uniform vaccine application

type vaccines

wing web mass application1