15 commentsupdate:Dec 23, 2011

Vaccine reactions in poultry flocks

Disease causing organisms are ubiquitous in poultry producing facilities all around the world. Vaccination is one of the tools in the arsenal that is frequently used. Vaccination does not provide a 100% guarantee that a disease will be prevented from causing losses.

Disease causing organisms are ubiquitous in poultry producing facilities all around the world. Vaccination is one of the tools in the arsenal that is frequently used. Vaccination does not provide a 100% guarantee that a disease will be prevented from causing losses. In most situations, vaccination serves as a means to reduce/minimize the economic impacts of certain diseases.
Following the administration of a live vaccine in poultry, the vaccine virus must infect target cells and replicate to increase their numbers in order to stimulate the immune system. If the vaccine is administered properly to healthy birds, a "normal" vaccine reaction will occur although this normal reaction can vary considerably among flocks.
A good basic rule is that a mild respiratory reaction should be detected at 2 to 3 days following vaccine administration and should last for 5 to 7 days. The clinical reaction in the birds will include respiratory noise (snicking), head shaking and watery eyes. These reactions should be self-limiting. If no reaction is detected, it is likely that little or no stimulation of the immune system has occurred. In this case, the birds are still susceptible to field disease challenge. If the reaction is more severe  than desired or it is not self-limiting, this is cause for concern and should be investigated.
Excessive vaccine reactions
It is often reported in the commercial poultry industry that chickens routinely need to be treated with antibiotics following vaccination to "buffer" the reactions and to control secondary E.coli septicemia and airsaculitis.
Many of these flocks finish with poor body weights, poor uniformities, high feed conversions and some even experience increased mortality due to the severe or prolonged vaccine reactions.
Chick quality, uniformity of maternal antibody, vaccine strain, vaccine administration, health status of flock (presence of immunosuppressive conditions, Mycoplasma gallisepticum infection, etc) and poultry house management are among the most common factors that can play an important role in the severity of vaccine reactions  especially when respiratory disease vaccines are administered.

Excessive reactions unacceptable

Simply living with excessive vaccine reactions and the associated losses is totally unacceptable in today's highly competitive industry. Some operations experience this problem more than others.
How often do you encounter with this problem in your farm?
Do you think that treating affected flocks with antibiotics is the best available solution to cope with this problem?
Are you one of those people who always blame vaccine quality as the main cause of these reactions?
What are your suggestions to reduce/minimize the occurrence of these reactions?




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    Pieter Kuhne

    I think most of the reactions are caused by a sub optimal application of mainly respiratory vaccines. Most vaccinators do not know the difference between a fine and a course spray. First vaccinations with respiratory vaccines (in the hatchery) must be applied with a big droplet, small droplets penetrate too deep in the respiratory system and are the reason for post vaccineal problems.

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    dr. Nagy Gyula

    In my more than 30 years praxis in poultry health care, never have seen only very slight vaccination reactions after spray vaccination. 90% of the reacting cases occured with lower quality flocks (Mg etc.)The condition of reactionfree vaccination : Healthy chickens, correct environment in the house, proper equipment, correct dissolving vaccnes and finding the proper droplet size. If the vaccination is not done by the vet., one can face some more serious reactions including higher mortality fore some days.

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    i think that post vaccinal reactions is one of the main problem specialy in broilers so we should use antibiotics for mycoplasma and e.coli after carry sensitevity with good mangment

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    Karwan Mustafa

    I think vaccins causes some problem, bacause there is some viros even its unactive but still viros and body try hardly to make antibody aginst those strange entraces,my suggetion is use some anti stress vitamins in order to reduce the side effects, we saw same situation in human also when they vaccinated especially in childrens.

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    live vaccines produce immunity for 2 to 4 weeks range.Inactvated vaccines produce immunity for 3 to 6 months depending upon the potency of th vaccine.
    Prolonged vaccine reactions are the rsults of poor techniques generally such reaction prolonged does not happen unless u dont change the needles frequently or diseased birds on par with healthy birds are vaccinated simultaneously.

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    Keep up the great work!

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    bayo adeyonu

    excessive vaccinal reaction may be as a result of immume status of the chicks at the time of vaccination, handling and administration of vaccine and temperature of the pen during and after vaccination (low)

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    Prof H.A.Upendra

    I have seen post vaccinal reaction in breeder flock aged 12 weeks after vaccinating with R2B strain ND vaccine. The signs included paralysis of legs, wings and torticolis apart from green colored droppings. death was mainly due to inanition and there was no specific gross lesion. About 35% of male birds in the flock was affected.

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    Dr. Asim Mahmood Khan

    In my openion measurable vaccine reaction is a healthy sign,but should consider the factors like age of flock,MDAs,strain of vaccine,weather condition,flock status either MG+,MS+,droplet size,method of application,etc before vaccination a flock with live vaccine.Dr.Asim Mahmood Khan.Pakistan.

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    What is the best droplet size to be used for vaccinating birds against ND? Some uses the spray nozzle used for Mycoplasma vaccine, is that applicable?

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    Tarusenga Munyanyi

    vaccines are intended to produce immunity to infections once they start causing problems by reactions causing high mortality its longer important to vaccinate. Many vaccines are produced based on field challenges of outbreaks. However some vaccines are not pacified properly leading to severe reactions. Most people use an international vaccine programes leaving their own vaccination programes based on field outbreaks and epidemiology of the disease in their areas. It is important to know the patern of disease you intent to vaccinate against before vaccinating your flock. Vaccinate health flock, Dont vaccinate stressed flock. make sure you are vaccinating at the correct age. You may vaccinate birds that are already incubating the disease leading to outbreak soon after vaccinating then you may call it vaccine reaction.

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    When the technical people in poultry industruy mention about the post vaccination reactions (PVR)it is usually due to vaccination against ND or IB, particularly via spray method. There are several methods to reduce these PVR's. The mechanical method is limiting the invasion of vaccine virus by incresing the droplet size. The vaccine virus in big droplets can only reach to upper respiratory tract where native immune system has strong barriers and good irrigation system (mucociliar activity). On the contrary lower respiratory tract (LRT) particularly air sacs are deprived of these defense mechanisms and effeceted severly from vaccine starins itself and other invaders subsequently like E.coli or exacerbate already existing Mg infection by generating an extra stress factor for the birds. The biological method to reduce the PVR is using less patogenic starins like apatogenic enterotropic strains against ND. These strains are realy safe that they do not cause severe PVR as the peunomotropic starins even if they reach to LRT or the birds infected with MG. Also new technologies like vector vaccines available today giving an opportunity to ensure a good protection without using those highly reactive vintage vaccines. We must always keep in mind that the vaccines are to protect birds against mortality and economical loss so the vaccines causing economical loss by itself (with PVR) is not complying anymore what we and modern industry expects from them.

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    The vaccine reaction in a flock is a health sign, but too long reactions need to be investigated either with the dose of the vaccince applied or methods, ie: droplet size if the Post reaction is just by the applications one should thinks for its sparying tecniques like to increas the droplet size and time durtaion of the sparying and also look for the dose some time the Full dose not needed may be recomended by the manufacturer, one can increase the droplet size adding little more water for sparying to adjust the water amount for sparying the number of chicks to be vaccinated.

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    Dr M asif raza

    Post vaccination reaction is a realistic phenomina after vaccination but it's intensity depends on chick quality management of the farm ,route of vaccination,proper vaccination timing between the same vaccine,health status of the flock,quality of vaccine regarding its titres and preparation method adopted.

  • dr m irfan anwar

    article as well as the comments by the eminent poultry professional are realy informative for the poultry professional as well as growers

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