Compiled & shared by-DR. RAJESH KUMAR SINGH, (LIVESTOCK & POULTRY CONSULTANT), JAMSHEDPUR, JHARKHAND,INDIA9431309542, rajeshsinghvet@gmail.com.Vaccination may be considered as insurance against diseases. A successful vaccination program is dependent on many factors including vaccine handling, quality and nature of vaccine, use of local antigens, immunogenic response inside the body of the bird and following manufacturers’ instructions. Although the disease outbreaks against specific diseases in nonvaccinated flocks cause very high economic losses, the severity of disease outbreaks in properly vaccinated flocks is low. The potential threat of disease outbreaks even in vaccinated flocks cannot be avoided 100%, but the losses can be minimized through thoughtful consideration of success of vaccination program for poultry flocks. In India , there is a high incidence and prevalence of contagious diseases of poultry and vaccination is the only tool to prevent birds from diseases. Through preventing vaccine failure, the productivity of food items like meat and eggs can be increased in the country, and shortage of animal protein can be overcome and thus per capita availability of eggs and meat can be increased. Moreover, the poultry sector can play a better role in the economy of the country by decreasing economic losses due to vaccine failure, thus increasing annual share in GDP value and becoming a major contributor of the agricultural sector of the country.Proper vaccination is an essential part of a good poultry management program and for the success of any poultry operation. Effective preventive procedures such as immunization protect hundreds of millions of poultry worldwide from many contagious and deadly diseases and have resulted in improved flock health and production efficiency. Immunization cannot be a substitute for poor biosecurity and sanitation. Thus, vaccination programs may not totally protect birds that are under stress or in unhygienic conditions. The primary objective of immunizing any poultry flock is to reduce the level of clinical disease and to promote optimal performance. Certain vaccines may also have an impact on human health (i.e. Salmonella vaccines). For breeders – we also want to accomplish some additional goals:A. Protect the bird (as a pullet and hen) against specific diseases. B. Protect the progeny of the hen against.Poultry vaccines are biological products that induce an immune response to the specific disease causing agents. Depending on the vaccine, they can be administered in various ways, all of which are discussed in this manual. Depending on the type of antigen in the vaccine, the birds’ immune system will react, creating a “memory” response of antibodies and immune cells. The more a bird is exposed to the same antigen, the greater the antibody response and resulting protection. This is the reason many flocks are vaccinated multiple times for the same disease – to maximize the immune system’s response.Disease prevention through vaccination is one of the aspects of bio-security. Disease causing organisms can be classified as smallest to largest – viruses, mycoplasma, bacteria, fungi, protozoa and parasites. All these organisms are susceptible to chemotherapy, except viruses. Bacterial infections are controlled through antibiotics but not much medication is available to fight viral infections thus vaccines are used. Control of viral diseases is dependent on prevention through sanitation and bio-security and by vaccination. Vaccination is no substitute for effective management. Vaccine is effective in reducing clinical disease but exposed birds may still get infected and shed disease organisms. Vaccination before infection occurs in a flock is the best means of protection.Vaccines are intended to stimulate the immune mechanism of an animal to produce antibodies, which will inactivate pathogens and also produce minimal harm. Vaccine is a protective measure against outbreak of contagious and infectious diseases and plays a major role in preserving productive health of poultry.Vaccine contain specific biological substances called antigens (Ag).In the bird antigen is recognized as a foreign body and responds by producing specific antibodies (Ab). An ideal virus vaccine is made from a non disease producing highly immunogenic virus causing little reaction and much protection. Vaccine may be live or killed, both types give reaction. (A bacterial vaccine is live or inactivated preparations of bacteria termed bacterins).Live vaccine:—————–Live vaccine consists of live micro agents. Live vaccines are viruses or bacteria weakened under controlled laboratory conditions into a safe virus/bacteria strain that can infect the chicken immunity and stimulate immunity without causing severe disease. Live vaccines stimulate the complete immune system including local, cellular and humoral immunity. Protection following vaccination is relatively rapid (few days to a week) depending on properties of particular virus/bacteria. Protection for most of live vaccines does not last for a full breeder cycle and needs regular revaccination.Live vaccine can be administered by mass applications such as drinking water, spray or aerosol. Live virus vaccines reproduce in the host to increase their number. Most poultry vaccines are a live virus type. They can be given at a younger age than killed vaccine.Killed or inactivated vaccine:—————-Killed or inactivated vaccines contain pathogens that have been chemically inactivated with or without a suitable adjuvant so that they will produce immunity, but are unable to cause or transmit the disease. They are killed in such a manner that the part of the organism which injures the bird and allows the pathogen to multiply is destroyed, leaving the immunity stimulating portion of the pathogen intact. The adjuvant causes a mild reaction at injection site attracting cells such as macrophages, which start the immune response. Adjuvant also acts as a slow release formulation stimulating the immune system for extended period of time. Inactivated vaccines do not stimulate complete immune system like live vaccine. They do not induce local immunity and only limited cellular immunity but there is a very strong humoral response (circulating antibodies) and takes up to 6 weeks for this protection to develop. A killed virus product is dependent on the number of antigenic units (virus particles) present in the vaccine dose to stimulate antibody production.Inactivated vaccine must be administered by injection to each individual bird at the prescribed dose rate is laborious.Development of competent vaccines is one of the factors for emergence of poultry industry.Vaccination schedule aids in achieving maximum benefits through maximum protection of flock against disease. Under optimal standards of management & husbandry practices, with no exposure to pathogen a bird is sure to respond effectively to vaccination. In addition to providing all the nutrients through feed, strict bio-security rules following vaccination schedule is must. Small decline in any of the managemental practices can lead to irreversible loss, in form of disease outbreak.Parent flock is vaccinated in such a way that there are required levels of antibodies of major diseases in chickens. The yolk sac antibody protects the chicks from natural infection but is maintained till defensive organs (thymus, bursa, spleen & bone marrow) are fully functional (21 days of age). Vaccination schedule based on the parent flock vaccinations with slight variation based on season or prevalence of disease in area is helpful.More doses or higher frequency of vaccine does not have any effect on protection of bird. Only required amount of antigen is utilized to induce the immune system to produce antibodies, additional dosage is either eliminated or deposited hindrance the immune system in recognizing other antigens- immune-suppression develops leading to vaccine failure. Additional quantity/dosage leads to excess expenditure too.POINTS TO BE CONSIDERED TO AVOID THEIR INTERFERENCE DURING VACCINATION ARE:1. High level of passive immunity:Primary protection comes from immunity passed on by hen to her chicks called maternal immunity and is passive. Maternal antibodies may neutralize vaccine in young chickens, if given at too early stage. When the maternal antibodies disappear the chick is left unprotected, even though it has been vaccinated. Thus it is better to administer the vaccine when the passive immunity is low after about 5 to 7 days.2. Stress:Anything which upset physiological and psychological stability of bird is a stressor and reaction of an individual to the stressor is called stress. Stress leads to severe immune-suppression which may result in failure of vaccination. Vaccinate birds only under stress free condition.3. Inactivation of live vaccine & Spilling of vaccine:Improper handling during transportation, storage, and at time of administration may lead to failure of vaccines. Vaccine contamination must also be prevented as it can cause serious complications. Live vaccines should always be stored and transported at 2-8oC and never exposed to sunrays. The diluents should be chilled before the reconstitution of vaccines. Live vaccines are disease agents which can cause disease under certain circumstances. If vaccine dribble out it may become a source of disease in birds, thus tip out or left over vaccine must be neutralized with strong disinfectant and empty vials or droppers/containers for be burnt or disinfected to prevent accidental spread to other poultry.4. Health Status of birds:Immune system of a sick bird is weak and cannot satisfactorily withstand a vaccine. Vaccination of sick bird can precipitate the incidence of disease and it can also lead to other diseases. Sick birds should therefore, be allowed to recover before vaccination. Immunosuppressive disease cause immune-suppression in birds and the birds will not respond properly to the vaccine resulting in vaccine failure5. Temperature & Ventilation:Ambient temperature above 30oC affects the immune system of the birds adversely, so vaccinate birds during cooler period of the day only. Ammonia is produced as breakdown of uric acid (an end product of protein metabolism). Improper ventilation leads to higher concentration of ammonia (NH3) in poultry house due to which there is immune-suppression and failure of vaccination. This ammonia is prevented to accumulate in the poultry house by ensuring proper ventilation.6. Age, dose and route of vaccine:Route and dose prescribed by the manufacturer must be followed. Under dosing will not protect the bird adequately. The age of bird at vaccination, proper timing of revaccination affects the level, quality and duration of immunity. Vaccines may be administered:a) Parentally:Parental routes are:SubcutaneousIntramuscularIntranasalIntraocularb) Orally The vaccine is given orally through drinking water. Following precautions should be taken for proper oral vaccination in birds:i. Stop the water supply to the birds for one hour before vaccination in hot weather and two hours in cool weather.ii. Use plain water without any water sanitizer for mixing the vaccine.iii. Skimmed milk powder should be mixed in water before adding the vaccine to it. It should be mixed @ 3g/Lit of water. This prevents the microbicidal activity of the residual sanitizer and also it stabilizes the microbial antigens. The vaccine should be mixed in such a quantity of water as will be consumed by bird within one hour.iv. Follow the instructions from the manufacturer.CARE DURING VACCINATION PROGRAMME:—————1. Buy the vaccine from a reliable well recognized source after checking the expiry of vaccine, as they have limited lifespan within which they must be used.2. Vaccines should be stored at a temperature of 2o to 8o degree C. They should neither be frozen in a freezer nor stored above 8o C. Same temperature is to be maintained during transporting; a flask with ice cubes or iced water is also suitable for the purpose. In farm storage in lower compartment of refrigerator is suitable.3. Vaccination should be carried out during the cooler period of the day which reduces stress in birds. Temperature above 30oC may affect vaccine potency. Mixing of vaccine should not be done in sun, as direct rays will affect the potency and inactivated vaccines. Vaccine should be mixed and kept in shade during distribution period. Don´t use premixed vaccines kept overnight.4. As vaccines are vacuum sealed (administered via drinking water) when opened in air draw contaminated air into the container thus such vaccines must be opened under water into which it is to be mixed.5. Tape water is mixed with chlorine to kill germs and this water when used can kill inactivated live vaccine. All sanitizers in water should be avoided during vaccination, thus avoid such water or treat before use. Antibiotic treatment should be stopped three days before and after vaccination. Live virus vaccine are readily destroyed by sanitizers and chlorine. Water equipments should be free of disinfectant.6. For vaccination via drinking water, the amount of water for mixing varies with age, type of bird and climate. Water should be withdrawn 2-3 hours before giving the vaccine for fast consumption of vaccine. Remove water up to 2 hours in hot weather and 2-4 hours in cool weather before administration. All vaccines should be consumed within two hours of mixing; adding skim milk powder prolongs vaccine life. Adequate dosage of vaccine must be provided to flock. As water is withdrawn all birds will come to drink water so it is advisable to distribute the vaccine in more drinkers than needed for normal watering of flock.7. Designing and implementing an effective vaccination schedule requires a thorough knowledge of disease, risk situation in a specific area, an understanding about the interaction between chick and vaccine and thorough planning. Decide whether or not to vaccinate against a disease depends on the likelihood that the birds in a flock may be exposed to that specific disease.8. As a good breeder hen produces a maximum number of hatching eggs thus there must be least negative impact of disease on egg production. Broiler chicken also relies on breeder hen for maternally derived antibody during first few weeks of life for protection against disease. Thus breeder vaccination needs additional attention. For many viral diseases the breeder is primed with live vaccine followed by an inactivated booster vaccination 4-6 weeks later to provide protection for full production cycle.GUIDELINE FOR SUCCESSFUL VACCINATION:—————-Vaccination of poultry younger than 10 days (5-7days) of age cannot be expected to produce uniform or lasting immunity, even in the absence of maternal immunity. Exception is that vaccination for Mareks disease is ordinarily given on the day of hatch.Guideline for vaccine administration:a. Each vaccine is designed for a specific route of administration so use only the recommended route.b. Do not vaccinate sick birds (except in outbreak of laryngotracheitis or fowl pox).c. Protect vaccines from heat and direct sunlight.d. Most vaccines are living, disease producing agents so handle them with care.Layer Breeder————–Bulk of breeder vaccinations are administered in the first 18 weeks (rearing phase)Protection should be at peak level when first hatching eggs are collected and persist up to end of egg production cycle.To avoid stress to the breeder bird vaccination during lay is kept to an absolute minimum, generally limited to the mass administration of certain live vaccines (ND- Newcastle disease, IB-Infectious bronchitis).Vaccination at day old or in ovo with suitable MD-Markes Disease vaccine to reduce losses, Sensitive nature of vaccine used requires specific attention to vaccine handling and administration procedures. Vaccination in hatchery is preferred. Even the best MD vaccination does not equate guaranteed freedom.Vaccine against coccidiosis has been a routine addition to most breeder vaccination schedules. Administered correctly these vaccines induce a predictable immunity to the selected Eimeria strains.Broiler Breeder—————–Vaccination of the broiler breeder does not end at protecting the hen and egg production. Breeders immunity has a direct impact on the immunity of the broiler at hatch. Protection to offspring´s/chicks is transferred via yolk called maternally derived antibody (MDA). Chicks hatched in an environment will face the same disease challenges the hen faced in past, but there is balance now a day by keeping hen in one environment, hatching eggs in hatchery and raising broiler chick in different environment away from breeder.IBD-Infectious Bursal Disease is best example of vaccination in breeders primarily for benefit of broiler.IBD specific MDA protects the broiler from infection during the first two to 3 weeks, after which live IBD vaccines are administered.Vaccination of the breeder prevents transmission of reovirus via egg and transfers protective levels of reovirus specific MDA to broiler chick. Reovirus is associated with poor growth in broilers.Avian encephalomyelitis (AE) and chicken infectious anaemia (CIAV) are both viral pathogens transferred `from breeder to broiler via the egg.Breeders are vaccinated against salmonella and are less susceptible to salmonella infection; there is also reduced risk of salmonella transmission via the egg. The protection level of MDA transferred from breeder to the broiler protect against infection during 1st weeks post hatch, when broiler is most susceptible to infectionMethods of Vaccination———————-There are seven methods of vaccination which are used and are mentioned over here in detail. The reconstitution of vaccine is of prime importance. Users must apply all the steps of the reconstitution while using the live freeze dried vaccines.Intraocular (Eye Drop) or Nasal Instillation method————–This method of administration by Eye drop/ Nasal instillation should be preferably used for small dose packs as it is necessary to consume reconstituted vaccine immediately. If this method is to be used for higher dose packs it is advisable to use more vaccinators so as to utilise reconstituted vaccine immediately. Hold the chick with one eye turned up. Take the vaccine product in sterile prescribed vaccine-dropper and instill one drop in eye or nostril. Ensure that the vaccine drop is completely absorbed in the nostril or in the eye. In Nasal Instillation method the vaccine drop is inhaled by the chick on momentary pressing of the beak. Intraocular method of vaccination gives better immune response.Beak Dipping Method——————-Reconstituted vaccine should be mixed with requisite amount of chilled water (normally mixed with suitable amount of skimmed milk powder) in china-clay / glass bowl.Secure the chicks and dip the beak upto the nostrils. Chicks quite often will respond with a jerky movement of the forehead. Complete the vaccination within one hour. maintain the cold chain throughout the vaccination.Subcutaneous Injection Method———————-This method is specially used for inactivated vaccines and Marek’s disease vaccine, live Suncutaneous injection is often placed in the lower half, back of the neck. although field contamination due to unhygienic vaccine handling can result in extreme reactions at the site of injection, this region is not valuable part of carcass.Intramuscular Injection Method—————————Intramuscular injection of inactivated vaccines and of live vaccine like ND R2B & Fowl Pox, can be placed in several locations including the breast, thigh and wing. These types of vaccines have been commonly injected into the breast muscle of chickens, because intramuscular injection into the breast is an easy and accurate way to apply the vaccine.For subcutaneous and intramuscular vaccination method use 20G1/2 inch needle with a short bevel. Change needle after every batch of 100 birds for hygienic vaccination in order to reduce the post vaccinal reactions.Wing Web Prick Method——————–This method is used only for Pigeon pox vaccine. an applicator instrument is called “lancet” is used for this method of vaccination. the metal tips of lancet are dipped into reconstituted vaccine and pierced through the part of wing having the least number of blood vessels.Mass vaccination:Drinking Water Vaccination———————-The Oral vaccination of the birds through drinking water is the most practical method of vaccination in flocks of large size. Drinking water vaccination can be used for vaccinating birds with certain vaccines against Newcastle Disease (N.D.), I.B.D. (Gumboro Disease) and Infectious Bronchitis (I.B.). Quality ice @ 1kg per 10 ltr of water and skim milk powder @ 6 g per ltr water (Vacc-sure tablet can be used.) Always place the requisitenumber of waterers per batch of birds for having the better charging of vaccines to the flock.Vaccination by Dosing Pump———————–A dosing pump is a device, which allows constant, progressive and predetermined release of “stock Solution” into the drinking water of birds. The rate of incorporation is adjustable and classically varies from 2 % to 5 % . (for example a rate of 2 % means: 2 ltr of “Stock solution” released per 100 ltr of drinking water passing through pump). An important factor in vaccination by dosing pump is estimation of the volume of the “Stock-solution” and timing of work. Here the validation is important, wherein counter-check the released volume.Spray Vaccination———————The reconstituted chilled vaccine in the bottle us poured aseptically in chilled skim milk powder – water mixture.Use 2.5 grams of skim milk powder per ltr of distilled water. Clean mineral water which is of next choice if distilled water is not available. Use 300-500 ml of clean distilled water (skim milk powder – water misture) for every 1000 birds doses of the primary vaccine or 500- 1000 ml for repeat vaccinations. Various types of pumps for spraying of vaccine are available in foreign/developed countries for use in such vaccinations.However requisite spray pump available in the market can be used for spraying of the reconstituted vaccine described above. The droplet size of vaccine water sprayed through such pumps should be in the range of 150 & 175 micron size. This is of – course to avoid stress on the air sacs and further leading ti precipitation of mycoplasma existing in dormant form. Hence consult with the experts.Spraying of the vaccine is recommended at flow rate of about 300-400 ml per minute, keeping the distance of about 30 cm above the chicks. The birds can be vaccinated on day of arrival in the chick-boxes itself for desirable “take” of vaccination to avoid handling stress.However, upto 6th day, priming is also possible using this method while keeping the chicks in their chick guards and raising the brooding “Baskets” with bulbs at more height for 15-30 minutes till “vaccination” is completed. Since brooding method is used in your farm is not suitable for the spray vaccination as described above then religiously use eye drop or nasal or drinking water method for vaccination.Incase if CRD is noted in particular areas then the spray vaccination should be avoided as opined by technical experts.The vaccinator must put the aprons, mask, gumboots and goggles to protect themselves from transmission of any virus particles into system.Drinking water Method of Vaccination—————It is very common method used by all the poultry farmers. Most if the booster or repeat vaccination are done by drinking water. The number of drinkers are very important and should be places to make it available to all the chicks / birds so that every bird can get access tot he vaccinated water on the day of vaccine. Many times the water vaccination is done through nipple drinkers or channel drinkers in such cases the requisite pipeline should be throughly cleaned by pipeline cleaners. This pipeline cleaning should be done regularly but it should always be done three days prior to drinking water vaccination, to avoid any kind of detrimental effects of cleansing agent on vaccine virus.Age of Birds in Weeks 03 03 04 08 12 20 25 35 45 55Broiler Breeders 15 18 26 30 40 45 50 50 50 55Layer Commercial 10* 16* 24 25 30 35 35 35 35 35Layer Breeders 10* 16* 24 25 30 35 35 35 35 35Water quantity* during vaccination also depends on the holding capacity of pipeline. during 3rd and 4rth week period of Layer Breeder and Layer Commercial birds requisite quantity water should be matched for best water vaccination uptake. during intense summer season the above quantity of water can be increased 5 to 10% depending upon rise of the temperature to provide requisite water quantity during vaccincation.During winter and rainy seasons withdrawal period for water can be extended even upto 2 hours. Where as in intense summer withdrawal period should be upto 45 minutes only. But always see that vaccination water is consumed within 2 hours, whereas in normal case water withdrawal period can upto 1 and half hours, so that birds become thirsty.In nipple drinking water system the amount of water required during vaccination can easily be calculated based on the requirements of water required for two hours.In severe winter the water consumption comes down and hence during vaccination the water quantity will be comparatively less.Causes of vaccine failure—————–The causes of vaccine failure can be categorized into two major factors:antigen factor and host response.1. Antigen factorsThe protective vaccine antigen is of prime importance in the production of effective vaccine. The vaccines available in the market may have the following shortcomings resulting in vaccine failure.1.1. Improper formulation of vaccine1.2. Non usage of local antigens1.3. Improper storage temperature1.4. Exposure to direct sunlight2.1.5. Use of expired vaccines2.1.6. Mutation of viruses2.2. Host factors—————The poultry birds to be vaccinated against diseases may not respond effectively against vaccines due to the following shortcomings, thus resulting in vaccine failure.2.1. Stress on birds2.2. Concurrent disease.2.3. Immunosuppressive diseases2.4. Immaturity of birds.2.5. Interaction with maternal antibodies.2.7. Inadequate dosage.2.8. Lack of booster dose2.9. Wrong timing of vaccination2.10. Climatic factors
