The most common representative of live vaccines of the Massachusetts serotypes is the strain known as H120. This vaccine strain is known for the number of passages it has undergone in order to reach its typical level of attenuation. H120 vaccine is a mild vaccine, usually used for first vaccinations, it does not induce a long lasting immunity.
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.
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.
Read why vaccines can protect against different IB serotypes - Serotypes and Protectotypes.