Although Bovine Respiratory Disease (BRD) vaccination has been commonly associated with viral protection, Pasteurellas (M. haemolytica, H. somni or P. multocida) also play an important role as they are commensals in the upper respiratory tract of bovines.
 

Types of BRD lesions

When factors such as stress or viral infections occurs, the replication rate of these bacterial pathogens increases rapidly and they colonize the lung, producing severe lung lesions.

This includes in particular necrosis, thrombosis and substantial fibrin production, which in some cases can even result in the death of the calves. 
 

M. haemolytica: Effects and efficacy of vaccination

Mannheimia haemolytica produces the well-known “shipping fever”. Serotype 1 is the bacterium most frequently isolated from the lungs of cattle with BRD¹.

The leukotoxin is its most destructive virulence factor, producing the previously mentioned lung lesion¹.

The value of  M. haemolytica bacterin-based vaccines is questionable, and some studies show that they can even exacerbate the disease.

The most innovative vaccines include leukotoxoid, which are 50-70% effective in preventing pneumonia caused by M. haemolytica².
 

The importance of Histophilus somni

Since PCR diagnosis was developed, Histophilus somni is becoming increasingly and widely recognized as an important pathogen as well³.
This bacterium not only produces bacterial pneumonia but also septicaemia, resulting in: myocarditis, otitis, polysynovitis and thromboembolic meningoencephalitis⁴, most commonly named as "the sleeper syndrome".

The guidelines of the EU Commission for the reduction of antimicrobial use and improvement of the health status of farms currently require improvements in diagnosis and prevention.

HIPRA developed HIPRABOVIS® SOMNI/Lkt, the first and only vaccine in the EU that confers protection against the leukotoxin of Mannheimia haemolytica and against Histophilus somni.

This vaccine offers vet practitioners a different approach to BRD, by also providing protection against bacterial pathogens and reducing the use of antibiotics by up to 80%.⁵

Reducing the economic impact of the BRD is possible

The costs with the greatest impact on value are treatment costs and the loss of future production.

The BRD is one of the major health problems in cattle (especially during the growing period), and remains a significant cause of morbidity, mortality and considerable economic losses.

Different scientific articles have demonstrated that cattle with lung lesions have a lower average daily gain than those with healthy lungs.^6,7

HIPRABOVIS® SOMNI/Lkt showed a 50% reduction in pulmonary lesions and clinical signs compared to the control group (unvaccinated) following experimental infection with H. somni and M. haemolytica.^8,9

At ANEMBE, 2017, a poster was presented which showed a period of protection of 40 weeks.¹⁰

REFERENCES:

1. Griffin D: Bovine Pasteurellosis and other bacterial infections of the Respiratory Tract. Vet Clin N Am-Food A 26(1):57-71, 2010.

2. Rice JA: Mannheimia haemolytica and bovine respiratory disease. Anim Health Res 8(2):117-128, 2007.

3. Tegtmeier C et al: Comparison of bacterial cultivation, PCR, in situ hibridation and immuno histochemistry as tools for diagnosis of Haemophilus somnus pneumonia in cattle. Vet Microbiol 76:385-394, 2000.

4.Perez DS et al: Histophilus somni: pathogenicity in cattle. An update.An Vet 26: 5-21, 2010.

5. Foix A et al: Efficacy of a commercial vaccine containing Histophilus somni and Mannheimia haemolytica leukotoxoid

in young calves under field conditions. Poster presented at the World Buiatrics Congress (WBC), Dublin, Ireland, 2016. Abstract retrieved from: http://www.wbc2016.com/book-of-abstracts/

6. Gardner BA et al: Health of finishing steers: Effects on performance, carcass traits, and meat tenderness. J AnimSci 77:3168–3175, 1999.

7. Wittum TE et al: Relationships among treatment for respiratory tract disease, pulmonary lesions evident at slaughter,

and rate of weight gain in feedlot cattle. J Am Vet Med Assoc. 209(4):814-8, 1996.

8. Foix A et al: efficacy of HIPRABOVIS® SOMNI/Lkt in front of a challenge infection with Mannheimia haemolytica in young calves. Poster presented at the BCVA, Southport, UK, 2015.

9. Foix A et al: efficacy of HIPRABOVIS® SOMNI/Lkt in front of a challenge infection with Histophilus somni in young calves. Poster presented at the BCVA, Southport, UK, 2015.

10. Foix, A.; Roca-Canudas, M.; Relancio, B.; March, R. Duration of Immunity Conferred After Vaccination with HIPRABOVIS® SOMNI/LKT in Young Calves. Poster presented at ANEMBE, Spain, 2107.