Killed vs. Modified-Live Vaccines
For some antigens, veterinarians have to decide whether to use a killed vaccine or a modified-live vaccine. Each vaccine has its advantages, and each has its disadvantages. Most killed vaccines contain an adjuvant system, whose purpose is to stimulate an immune response. Without an adjuvant, the body is less likely to produce an effective response to the disease antigen. This discussion will cover the differences between killed and modified-live vaccines.
In order to make an informed decision regarding killed and modified-live vaccines, it is important to know the generally accepted characteristics of each type of vaccine advantage and disadvantage.
Killed Vaccine (inactivated)
No reversion to virulence
Safe in pregnant animals
Safe in immunocompromised animals
No shedding of the virus
Two doses often needed for initial response
MAY CONTAINS "TOXIC" ADDITIVES!!!
Less frequent transient adverse responses than killed vaccine
Parenteral or mucosal administration
Higher potential for vaccine-induced disease
Vaccinal virus shed
Viral replication implies:
Possible risk in pregnant animals
Possible risk in immunocompromised animals
Short shelf life when reconstituted
Easily inactivated by mishandling