Live vaccines

• Usually applied by mass vaccination (e.g., coarse spray or drinking water)
• Usually inexpensive
• Induce local as well as systemic immunity
• Cause some vaccination reaction that is observed for a few days after application

Live vaccine strains

Massachusetts strains

1. H120 and H52 vaccines

   The most common representatives of live vaccines of the Massachusetts serotypes are the strains known as H120 and H52. These vaccine strains are known for the number of passages they have undergone in order to reach their typical level of attenuation. Thus H120 is more attenuated than H52.

   • H120 vaccine - a mild vaccine, usually used for first vaccinations, does not induce a long lasting immunity.
   • H52 vaccine - is only used in previously vaccinated birds and provides a longer immunity. Its drawback is its residual pathogenicity in unprotected birds. Newer developments such as Nobilis IB Ma5 combine the advantages of the H120 strain without the drawbacks of the H52
2. Ma5 vaccine

   A mild vaccine that can be used as a single component. It can also be included in first vaccination in programs with IB 4/91 vaccines and inactivated vaccines for broad protection against different IBV serotypes.

Variant strains

1. IB 4/91 vaccine

   Contains a strain of the 4/91serotype for specific protection against that IBV type. Combined with Ma5 and IB multi vaccines, broad protection is provided.

2. IB 274 vaccine

   Contains a strain of the D207(D274) serotype for specific protection against that IBV type or related serotypes. Combined with Ma5 and IB multi vaccines, broad protection is provided.

Read why vaccines can protect against different IB serotypes - Serotypes and Protectotypes.