Dear members, I would like to know your opinion about the use of recombinant vaccines to prevent ILT, Newcastle disease and Marek´s Disease in chickens. What are the advantages and disadvantages in comparison with Conventional Poultry Vaccines? Look forward to hearing your experiences!
Future disease control through vaccination will mainly depend upon recombinant vaccines. It is in use at present in sizable proportion. For use of the recombinant vaccines it is mandatory/ compulsory for vaccine to be used to be registered in country of use after fulfilling the legal requirements. First you have to look please weather theses vaccines are allowed legally in the country of use. Recombinant vaccine is the induction of antigenic protein producing/coding genome into some other vaccine, so that by vaccinating one vaccine, you also get the immunity against the other disease whose genome has been inducted in to vector vaccine. For examle Nd vaccine as recombinant with HVT vaccine , IBD with HVT vaccine and so on. Following are the some of the advantages of recombinent vaccine. A: - By administration of one vaccine (as recombinant vaccines are live vaccines), recombined/ inserted genome also replicates along with virus/antigen being used as vector. Immunity is produced against both by single administration. B: - It has least disturbance against maternal antibodies which interfere with immunity process. This vaccine can be done in ovo i-e in incubating egg, so when the chick is hatched it will have immunity levels against the diseases for which vaccine has been done. In this way it will give better protection in areas of high challange for pathogens/ diseases. Recombinant vaccine either not repeated or with long intervals depending upon the health /titer of the bird against specvific vaccine used. This vaccine can be administrated at hatchery by skilled staff or at farm to get better protection.While if not recombinant vaccine used then vaccine used at farm and administration of vaccine not reliable, while at hatchery or in ovo it is being done by automated machines by skilled staff and produce better results. C: - Disadvantages. as it has not long usage record so disadvantage should be highlighted after use of recombinant vaccine for some time. D: - By advancement in molecular techniques recombinant vaacine making trend will increase. E: - It does not disturb maternal antibodies. As in IBD single IBD dose given through injection at day 1 will not interfere with maternal antibodies and will give protection for long time with single dose administration, which avoids stress of vaccination at least against for revaccinations. This will help in better performance. Regards, Syed maqsood Haider Jaffery
In addition to the live vector vaccines based on different viruses (mainly on HVT), inactivated vaccines for poultry has also hugh advantages in its safety and efficacy. ABIC biological laboratories (Phibro animal health care corporation) develop and produces several recombinant vaccine against infectious bursal disease and against egg drop syndrom disease. These vaccines are very efficient and more targeted to produce neutralizing antibodies against the specific pathogen. As I know Dow agroscience developed recently subunit vaccine against NDV based on HN protein, I wonder if somebody have idea for its efficacy? Best regards, Dr. Avi Zrachya ABIC biological laboratories Ltd.
Dear Dr. Jaydip, Many thanks for your kind response, In the following you could find all vaccine types related on two opposite parameters: Safety vs. Efficacy. EFFICACY --- nucleic acid vaccines - subunit - virus like particles - inactivated virus - non-replicating viral vectors - replicating vectors - jennerian - live attenuated virus --- SAFETY It is obvious that replicating vaccines will enhance the immune system better than non-replicating vaccines. That is due to the activation of the two arms of the immune system. On the other hand, subunit vaccines is more safe to use and from our experience it is also very efficient! For example: IBDV encode two proteins which creat its envelop and coating the viral genome - VP2 and VP3. It was shown that VP2 only is important for inducing neutralizing antibodies against the virus. For this all the recombinant vaccines against gumboro involve this protein either for live vector vaccines or subunit vaccines. For vaccination workplan against IBDV for broilers you could contact our veterinars Dr. Beny perelman (email@example.com) or Dr. Udi Ashash (firstname.lastname@example.org). Hope that this information helps, BR, Avi.