Vaccination

VACCINATION
  • There are three types of vaccines used for ND:
  • Live lentogenic vaccines are usually derived from field viruses that have been shown to have low pathogenicity for poultry but produce an adequate immune response. Typical vaccine strains are HB1, La Sota, F, V4 or Ulster 2C viruses. These vaccines are given to young chicks through eyes are nostrils. They are very safe and only La Sota will produce mild post-vaccinal reaction in certain flocks. This type immunization is also called as priming. 
  • Mesogenic strains are used only in areas where ND is epidemic and in village chickens. Normally mesogenic vaccines, such as Komarov and Mukteswar are used as secondary vaccines after a primary vaccination with a lentogenic vaccine.
  • Inactivated vaccines are produced by growing a ND virus in eggs, and then treating the infective allantoic fluid with an inactivating agent, such as formalin or betapropiolactone. An adjuvant, such as mineral oil, is usually then added to make the inactivated virus more immunogenic. Inactivated vaccines are usually applied after an initial priming vaccination with a live vaccine.
  • Thermostable live vaccines: Some asymptomatic enteric viruses have greater heat resistance than more conventional lentogenic viruses. This property has been enhanced by selection and cloning in the laboratory to produce heat tolerant vaccines. These have a distinct advantage in the village situation because it is possible to transport the vaccine without a cold chain.
  • Recombinant vaccine: APMV-1 has two surface glycoproteins, fusion [F] and haemagglutinin/neuraminidase [HN]. The genes coding for either of these can be inserted into a different virus like herpes virus of turkeys to produce a vaccine, which gave good protection against virulent NDV.
  • Marker vaccine: Recently an immunodominat epitope of NP gene has been identified and replaced with mouse herpes virus gene. The resultant vaccine helps to differentiates between vaccinated and infected birds.

Vaccine application methods

  • Mass administration through water or aerosol spray
  • Feed based techniques
  • As eye and/or nasal drops     
  • As injection
Last modified: Tuesday, 28 September 2010, 10:17 AM