example, when the disease is mild and sporadic, it is suggested that the following order of vaccination be
adopted: live Hitchner-B1 by conjunctival or spray administration at 1 day of age; live Hitchner-B1 or LaSota
at 18–21 days of age in the drinking water; live LaSota in the drinking water at 10 weeks of age, and an
inactivated oil emulsion vaccine at point of lay. For the second example, when the disease is severe and
more widespread, the same protocol as above is adopted up to 21 days of age, and this is followed by
revaccination at 35–42 days of age with live LaSota in the drinking water or as an aerosol; this revaccination
is repeated at 10 weeks of age with an inactivated vaccine (or a mesogenic live vaccine) and again repeated
at point of lay (Allan et al., 1978). The first protocol is generally applicable to countries were virulent NDV in
not endemic and is intended to minimise productivity losses by using a milder vaccine during the initial
vaccination. Considering possible constraints of ND vaccination, particularly applying to live vaccines, proper
immunisation should be validated by serological testing of vaccinated flocks. Regardless of which test
system would be applied, i.e. ELISA or HI, humoral immune response should be demonstrated at the flock
level.
example, when the disease is mild and sporadic, it is suggested that the following order of vaccination beadopted: live Hitchner-B1 by conjunctival or spray administration at 1 day of age; live Hitchner-B1 or LaSotaat 18–21 days of age in the drinking water; live LaSota in the drinking water at 10 weeks of age, and aninactivated oil emulsion vaccine at point of lay. For the second example, when the disease is severe andmore widespread, the same protocol as above is adopted up to 21 days of age, and this is followed byrevaccination at 35–42 days of age with live LaSota in the drinking water or as an aerosol; this revaccinationis repeated at 10 weeks of age with an inactivated vaccine (or a mesogenic live vaccine) and again repeatedat point of lay (Allan et al., 1978). The first protocol is generally applicable to countries were virulent NDV innot endemic and is intended to minimise productivity losses by using a milder vaccine during the initialvaccination. Considering possible constraints of ND vaccination, particularly applying to live vaccines, properimmunisation should be validated by serological testing of vaccinated flocks. Regardless of which testsystem would be applied, i.e. ELISA or HI, humoral immune response should be demonstrated at the flocklevel.
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