9 field experiences that proved beneficial effects of mastitis vaccination
As explained in previous entries, immunization against the pathogens that cause bovine mastitis can be a reality, if we include vaccination in our mastitis control programmes. In this entry, we’d like to share with you some field experiences that proved beneficial effects of vaccination against mastitis in dairy cows. Find here also a brief classification of the types of vaccines that can be found in the market.
BENEFICIAL EFFECTS OF INACTIVATED VACCINES AGAINST STAPHYLOCOCCUS
The first example comes from a study that used an inactivated vaccine of S. aureus (Nordaugh et al., 1994) and showed its positive effect on the appearance of clinical cases in the vaccinated group of cows as opposed to 6% of cases in the non-vaccinated group.
With regards to cases of subclinical mastitis caused by S. aureus, it was diagnosed in 8% of the vaccinated group and 14% of the unvaccinated group of cows.
In Israel, in a field trial (Leitner et al., 2003) a vaccine composed of fragments of S. aureus obtained by sonication was used.
It showed statistically significant beneficial effects with respect to milk production and SCC (Somatic Cell Count) in the group of vaccinated cows.
The important thing to note in a vaccine against S. aureus, is to vaccinate as early in the life of the cow as possible.
This immunization should be performed in pre-partum heifers, thereby avoiding potential infection that would compromise the productive life of the animal.
WHAT ABOUT COLIFORM MASTITIS Vaccines?
After performing a challenge with a virulent strain of E. coli in a group of cattle vaccinated with the E. coli J5 bacterin and a non-vaccinated group, (Hogan et al., 1995) it was showed that duration of intramammary infection, as well the intensity of the symptoms of mastitis in dairy cows were lower in the vaccinated group.
Also, in another field test (Deluyker et al., 2005) it was founded that, although vaccination against E. coli does not help in reducing the number of cases in the vaccinated group compared with the non- vaccinated, there were significant differences in the number of cases of systemic toxic bovine mastitis in favor of the vaccinated group.
In the case of S. aureus, various types of vaccines have been developed in the past with mixed results.
These vaccines could be divided into the two major groups:
1. Bacterin mastitis vaccines.
The first group, with bacterins, are vaccines prepared with all of the components of the bacterial cell and they may be dead or alive.
Therefore, mastitis tests in dairy cows were developed with this type of vaccine (Pankey, 1985 and Leitner, 2003).
2. Vaccines including elements of antigenic importance.
The second group, are those vaccines that include a component of the bacterium considered to be of antigenic importance.
These vaccines are developed from virulence factors such as expolysaccharide, or also called Slime Associated Antigenic Complex (Yosida et al. 1987, Calzolari et al. 1997 and Giraudo et al., 1997), among others.
Content originally created for “STARTVAC Library No. 1”.
Author: Marcelo Chaffer.
Atlantic Veterinary College | Prince Edward Island University | Canada.