Maternal Antibody Interference in Newcastle Disease Vaccination
Did you check whether this affects the sub conjunctival or intra ocular means of vaccination with B1 hitchner or B1 lasota? I guess strongly that subconjuctival immune glands called haderian gland will prevent the antigen to get to the bloodstream for antisera attack. Could you please discuss this?
Dr. Charles Ibe, Dear Dr. Ibe, I am in agreement with you. The purpose of 0-3 day ND vaccination (I/O;I/N) is not to induce antibody-mediated humoral immunity. Instead, this method invokes the phenomena of viral interference and interferon-mediated innate resistance, a well know fact with regards to all myxo- and paramyxoviruses. This imparts local immunity preventing entry of field virus via the URT. Yes, MDAs do interfere with induction of demonstrable anti-NDV HI antibodies since there is no viraemia owing to the presence of maternal antibodies. A second week vaccination administered by oral route when MDAs have significantly declined, will be able to induce HI antibodies.
Lalit Belwal I totally agree with you. When it's a matter of maternal antibody our prime motive should be to negate these antibodies. But it should be in our mind that what we are going to negate can protect birds up to first fourteen days or not. If maternal antibodies can protect birds for at least fourteen days we should not negate. If maternal antibodies are not protective but at the same time can interfere normal vaccination schedule we must negate these with an economical shot.
Good work. day old live vaccine can be a reason for the failure of vaccine as it is neutralized by mab.
Many people are now a days attributing the failure to emergence of new strains of nd which may require revision in the thinking. n.d is known to be a single strain for a long time.
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Birds were not challenged, this type of research has no value. Birds can be protected very well without antibodies.
Serological evaluation is a way of estimating the protection levels in the flock. This is the guideline to judge the effectiveness of vaccines practiced everywhere.
Challenge is another tool. It requires a controlled facility to expose birds to live virus and count the mortality. Somebody with facility can take it up. it is a proven fact that birds with higher levels of antibodies live better when challenged with live virus.
Yes, birds with low levels of antibodies also live till they are exposed to disease. Once they are exposed, the group having low titers face more mortality.
HI titer evaluation as a response to vaccination at different points is a good lead for further research like exposure evaluation.
As a poultry grower, I will postpone my ist vaccine to 5th day from day one to avoid maternal antibody interference.
Dear
In high epidemic area, such as the middle east -especially gulf region-, we should vaccinate at day old in spite of high maternal abs level in chicks due to vaccination at day old will provide local immunity which important for protection against Nd challenge and prevent filed strain to attach with receptors
So you can review about using ND vector vaccine which did not interfere with maternal abs and may provide cell mediated and humoral immunity.
Thanks & regards.
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