Vaccines used in Camels Ahmad Al-Majali, DVM, PhD Food and Agriculture Organization of the UN Riyadh, KSA

Camels-What is different? Little is known about this animal Complement system: – Camels appear to have demonstrable levels of classical pathway hemolytic activity throughout their lives – Like some other ruminants they have relatively high level of hemolytic complement activity (Males are higher than females) – Camels between 3 months and one year of age have higher levels of alternative complement pathway activity – Complement activity vs Trypanosoma evansi infection – Why the complement activity is low in camels infected with Trypanosoma.

Camels-What is different? Neutrophils – Vary with age: Young camels have larger numbers – Neutrophils:lymphocyte ratio is different from other ruminants: in other ruminants this is 1:2 in camels it is the opposite. – Neutrophils are of smaller size than other animals – Studies suggested that camels’ neutrophils are more active during infection than in other animals.

Camels-What is different? Eosinophils – Eosinophils in camels more polymorphic than any other animal species – Camel eosinophils also appear to be especially effective killers – When activated they reveal hyper-segmented nuclei (appear to be of high importance in killing parasites)

Camels-What is different? Camelid Antibodies – Three types of immunoglobulins in camels, and their associated subclasses, namely IgG1, IgG2, IgA and IgM. These antibodies were also reported to be antigenically distinct from those of other farm animals and man. – Heavy-chain antibodies (HCAbs) (lack of CH1 domain) – Camel HCAbs not only react with a wide range of antigens, but also interact with certain antigens differently than conventional antibodies

Most commonly used vaccines in Camels Most of the used vaccines are not especially designed for camels Cattle doses are usually applied and most vaccines used are never been tested for efficacy and safety in camels Most of the practices are based on experience rather than proved scientific research!!!!

Used vaccines and approaches Bacterial Diseases DiseaseType of vaccineApproach Clostridia spp. (enterotoxemia) Toxoid and bacterin (10 strains) -Initial injection at 2 months of age -Booster in a month -Repeated every 6 months -Benefit from passive vaccination Bacillus cearusPolyvalent enterobacteriacae vaccine PasteurellosisIn activated P. multocida and M. haemolytica BrucellosisS19 or Rev 1-Before puberty -Once per life time -Can be repeated in case of outbreak -Cattle dose is applied

Used vaccines and approaches Bacterial Diseases DiseaseType of vaccineApproach SalmonellosisBacterin (S. Typhimurium)-As in cattle ParatuberculosisBacterin (Mycobacterium Paratuberculosis-bovis) -As in cattle LeptospirosisCattle serovar-Vaccinate at 2 months age -Only when endemic -Repeat 4 times a year -When high number of shedders (dogs)

DiseaseType of vaccineApproach Camel pox-MLV (Jouf 78 strain) -Killed -Initial at 2 months of age -Booster at 12 months of age -Protect for life time except for the killed vaccine should be repeated annually Neonatal diarrhea (Rota and Corona virus) In activated bovine rota and corona virus -Initial injection at 2 months of age -Booster in a month -Repeated every 6 months -Benefit from passive vaccination Used vaccines and approaches Viral Diseases

DiseaseType of vaccineApproach Rift Valley Fever-MLV (Smithburn) -MLV Clone 13 -SR dose -Once per life time -At age 2 months West Nile Fever-Recombinant vaccines -Equine strain -Cross protection different strains -Prior to mosquito season -Horse dose -Adverse effect (injection site inflammation) BVD-Killed -MLV (S1 and S2) - As in cattle RabiesKilled rabies (cattle vaccine) -As in cattle start at age 2 months and repeat yearly Used vaccines and approaches Viral Diseases

Others DiseaseType of vaccineApproach Dermatophytone-Trichophyton -Microsporum -4 months of age -Boost after 2 weeks -Annually

Rev 1 in Camels Safety and Immunity Many studies on immunity but only few on safety Camels of Hajanah (police camels that guard borders) Used Rev 1 (full dose) conjunctival (2 SR dose) Monitor shedding (feces and milk), LN biopsy, Abs

Clearance in LNs

Shedding in Milk and Feces

Ab response

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