MLV vs Killed vaccines

[Jeanne - Simme Valley]

Here is a quote out of the program I attended few weeks ago from W. Mark Hilton, DVM, Beef Cattle, Purdue Univ.
"Which vaccines to use, non-infectious (killed) or MLV?"
"The following basic principles must be applied in decisions on the use of killed vs. modified-live viral vaccines:
(1) noninfectious vaccines (killed) generally require multiple doses (2 - 6 weeks apart) to immunize and one dose has no benefit at all, i.e. vaccinating pregnant cows once yearly with killed vaccine does nothing;
(2) the immunity generated by noninfectious vaccines is short-lived, requiring boosters every few months to 1 year apart for maintenance;
(3) noninfectious vaccines do not stimulate local immunity at all and either do not stimulate or poorly stimulate cellular immunity;
(4) noninfectious vaccines are very effective in stimulating humoral immunity and are more effective than MLV in stimulating a secondary immune response, because of the increased amount of antigen in the noninfectious vaccine;
(5) MLV provide cellular and humoral immunity that persists for years to life and are the first choice for successful immunization of young animals;
(6) MLV can cause abortion in unprotected pregnant animals or desease in immunologically compromised animals. Newer labeling has allowed use of MLV in pregnant cows IF they had the same vaccine less than 12 months previously. Never assume a cow has been vaccinated previously.
(7) MLV can have a negative effect on the corpus leutem of a cow that is about to be bred, so you need to vaccinate at least 30 days prior to breeding.

In most instances the use of a MLV is the most cost-effective choice to use. To use these vaccines timing must be correct. For example, non-immune heifers can experience inflammation to their ovarian tissue and cause a reduced pregnancy rate if vaccinated too closely to the time of breeding. We recommend vaccinating heifers 30-60 days prebreeding with MLV IBR-BVD vaccine.

There are many vaccines available for use in cattle and every herd should have a program in place with their herd health veterinarian."

 

[randiliana]

This article from the University of Florida is very much worth reading. Talks about how different vaccines work, both in mature animals, and in animals that still have maternal antibodies. Very interesting and informative.

http://edis.ifas.ufl.edu/VM063

 

[milkmaid]

Good article Jeanne, thanks for posting.

 

[rockridgecattle]

TNMBP, if you has problems with cows vaccinated with ML, it is a good chance they were PI calves that made it to the breding stage in life. They would continue to shed the virus, giving birth to PI calves, creating a nasty cycle.
Any animals developing sickness that require alot of a fair bit of treatment after ML vaccinations should be tested for things like BVD.

 

[Jeanne - Simme Valley]

The old MLV used to have a certain % of cattle get sick, but I think that is a rare thing now.
I've used it for many years, and never had anything get sick and needed treating.
But, that's why we live in USA - we have options & choices.