Prevention, Preparation and Administration
  1. Vaccination :At the moment there are several  vaccines commercially available:• Monovalent vaccines:HVT:  Herpes Virus of Turkeys (MDV Group 3). Widely used in many countries. It has beengiven very good results in the past, but protection is now insufficient in many countries. HVT is marketed in cell-free (Lyophilized) and cell-associated (under liquid nitrogen) form .CVI 988:  This is the so called “Rispens” strain. It is an attenuated Group I MD virus, which means that originally it was a pathogenic chicken Herpes virus, weakened by attenuation. In the past there was a fear that this vaccine could turn into a pathogenic form again and therefore it was not allowed in some countries. Experience in the field during many years proved there was no risk whatsoever in using this vaccine. In some countries where Rispens is not allowed, a cloned strain called CR6 is used on a small scale. Rispens   vaccine is a cell-associated strain, so it has to be stored under liquid nitrogen.

  2. Hygiene

  3. Vaccine administration :The Eva administration can be done intramuscular, in the leg and /or sub cuthaan, in the neck. If  adouble vaccination has to be given, it is better to do one in the leg and one in the neck. The prepared vaccine must be used within 3 hours. In most countries the chickens receive 0.2 cc vaccine. If only one droplet is lost, app. 15% of the total vaccine is lost !Needles must be changed after every 1,000 chickens or earlier if indicated by e.g. bleedings