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Autogenous vaccines are another alternative for the prevention and control of infectious diseases in poultry. Just like commercial vaccines, autogenous vaccines contribute to minimize production losses, achieve better sanitary conditions, and maximize productivity.
The difference between them is in the agents used as antigens: while commercial vaccines use standard strains, autogenous vaccines use autologous strains – the same agent that is causing the disease on the farm.
In addition, commercial vaccines are developed to prevent a certain pathology, in many different regions of a country. Autogenous vaccines, on the other hand, are customized products, i.e., they must be used for a specific farm and/or affected nucleus, and not generalized to all the units of a company.
This means that they are produced to meet the specific needs of disease prevention when the disease has already been diagnosed in the breeding stock or farm. The bacterial – or viral – agent is isolated, identified, replicated, and inactivated by specialists using appropriate techniques, and only then applied to the animal or flock itself.
Here we explain in greater detail about this tool that is already available for use on farms. Customized programs gain prominence when commercial vaccines do not provide the appropriate protection to the birds, and are essential to reduce production losses and animal mortality.
But before applying the so-called autovaccines – and for the results to be satisfactory – it is important to consider a few points. Biocamp’s technical and commercial director, Paulo Martins, cites 3 of them. Check them out!
1) Correct problem identification and diagnosis
In poultry industry, clinical conditions with multifactorial origins are not uncommon. We are talking about:
- Systematic biosecurity failures in the production chain;
- Stress conditions caused by management and/or environmental failures;
- Extreme weather conditions;
- Nutritional and/or infectious immunosuppressive factors;
- Primary infectious agents;
- Secondary infectious agents.
Therefore, the repetition of a condition in the same flock (or in different flocks), in the same operation or in the region serves as a warning. Since the vaccine protocol must meet the cost x benefit demand of the producer, it is important that the technicians know the correct diagnosis of which disease is affecting their flock in order to use the right technology.
For a correct diagnosis, the anamnesis, history of the flock(s), analysis of the control sheets, clinical examination, symptoms, and necropsy are fundamental. A successful diagnosis also depends on other factors, such as:
- Type of material collected;
- Aseptic conditions at the time of collection and transport to the diagnostic laboratory;
- Culture media used for the isolation of each of the agents supposedly involved;
- Identification of the isolated samples, among others.
Paulo Martins explains that, before producing autovaccines, it is important to evaluate all these criteria, as well as if the simple result of molecular tests is sufficient for diagnosis and if the isolation of the agent matches the clinical profile, lesions found, and extent of the problem.
Moreover, whether it is possible to reproduce the clinical or pathological condition by means of an experimental inoculation, and whether the diagnostic laboratory has the expertise not only to isolate, but also to detect fastidiously growing bacteria.
2) Production time
The manufacturing stages of autogenous vaccines can take two months – or even more – of intensive work. This includes everything from collection of the sample to product commercialization, going through all the other stages: isolation, identification, adaptation of the sample to culture media, multiplication and inactivation of the agent, quality control and documentation.
In most cases, bacterial autovaccines require two doses, four to six weeks apart, to establish a longer-lasting immunity. And, preferably, they should be administered during the rearing period of long-lived chickens. “It is not uncommon for some target flocks to have left the rearing stage and be in production by the time the quality control work for an autovaccine is completed,” explains Paulo Martins.
Furthermore, the multiplication of a new microorganism, newly delivered by the diagnostic laboratory, depends on countless trials and errors before its multiplication, in adequate concentrations, can serve as an antigen.
3) Immunogenicity
In some cases, the humoral immunity developed by autovaccines is not as effective in reducing and controlling infection as is the case following the application of live vaccines. The latter are able to better promote cell-based immunity and, depending on the route of application (digestive or respiratory), even produce mucosal or local immunity (IgA).
However, autovaccines can provoke cell-based immune response when they are administered as a booster. That is, when the animals are already sensitized with the corresponding live vaccines.
This is the case with Salmonella paratyphoid vaccines, when a primer of live attenuated bacteria is used. As an example, we can cite live vaccines against contra Salmonella Enteritidis or Salmonella Typhimurium, with subsequent vaccination with inactivated vaccines (commercial or autovaccines) before production.
Autogenous vaccines: when to apply in the farm?
Diagnostic accuracy, production time, and immunogenicity – as well as higher cost – are some of the factors that evidence caution in the use of autogenous vaccines. For all these reasons, the orientation is that, whenever possible, the farmer, the technician, the sanitarian and the industry use commercial vaccines regularly registered in the regulatory authority of each country.
These products have a long period of research, development, and experience in their use, in the most varied field conditions, in addition to specific quality control for each product, developed over years and even decades.
Only when the commercial line vaccines do not show the adequate response to a certain condition or pathogen (or are not commercially available for a certain infection or disease), it is advisable to consider using autovaccines, produced with inactivated microorganisms emulsified in oil or aluminum hydroxide.
In addition, prior to introducing the autogenous vaccine, it is also important to review biosecurity programs to try to identify if there have been any failures. “Many times, just by reviewing the processes and training the team, the problem can be reduced and even disappear,” says Paulo Martins.
However, if this does not occur, autovaccines become essential to control the outbreak of the disease and promote the immunity of the flocks housed on the same property. “When it is necessary to use an autovaccine, it is important to choose diagnostic and production laboratories with reference and expertise in their respective areas due to the complexity of the process,” explains Paulo.
The production laboratory must meet all the regulatory steps required by the authorities in each country, have adequate facilities, equipment, and technology, a team made up of technicians with extensive experience in adaptation and multiplication of microorganisms in culture media.
This is the case of Biocamp, which develops inactivated autogenous bacterial vaccines to meet the specific prevention needs of each farm. It is worth remembering that once the use of autovaccines is started, the results are consolidated after one or more production cycles.
So, if you have been experiencing challenges on your farm that commercial line vaccines are not solving, consider using autovaccines. Talk to Biocamp’s technicians and see how we can elaborate a program for your farm!
