immunology vacc dairy cattle (Risco) Flashcards
Ideal vaccine
- prolonged immunity
- free adverse side effects
- inexpensive
- stable
- response distinguishable from natural infection
Designing vaccine program
- disgned per needs of herd
- risk assessment
- dz hx
- biosecurity, animal movement
- vaccination hx
- breeding management: bulls used?
- intended management scheme and management practices
- risk assessment
Disease occurs when
herd immunity drops below level of disease pressure
Declining immunity
- stress
- weather
- poor nutrition
- calving
- disease challenge
- booster lapse
Colostrum
- can be thought of as a vaccine
- Colostrum
- immunoglobulins
- functional maternal immune cells
- interferon
- other immune factors
- vaccination to improve colostral quality
- vaccines against enteric calf pathogens
- E. Coli, rotavirus, coronavirus
- look for specific data on vaccine you want to use
- vaccines against enteric calf pathogens
maternal antibody interference
- may be a problem with some vaccines (minimal)
- mostly for diseases for which humoral immunity is primary protective mechanism
DZ that stimulate primarily cell-mediated protection
- BRSV
- BHV-1
- Parainfluenza virus
- leptospira borgpetersennii
*not blocked by maternal antibody
DZ that stim humoral response (antibody)
- BVD
- Mannheimia haemolytica
- Pasteurella multocida
*blocked by maternal antibody
Neonatal corticosteroids
- birth to 5 days
- systemic immune resonse decreased dramatically during first few days of life
- worst at 3 days
- back to normal at 5 days
Second period of reduced systemic immune system responsiveness
- between 3-5 weeks
- poorly understood
- corrosponds to when maternal T cells are disappearing from calf
- in calves fed fresh colostrum
- especially well documented for vaccines against the 4 primary viral diseases
Factors influencing vaccine efficacy
Stress
- don’t vaccinate 1 week before or 1 week after stressful procedures
- castration
- dehorning
- weaning and movement
Factors influencing vaccine efficacy
Stage lactation
- periparturient immune suppression
- 3-4 weeks pre and post calving
- delayed and decreased inflammatory responses
- may also delay or impair responses to vaccines
How to assess vaccine efficacy
- look at label
Label claims
USDA allows….
- Prevention of infection: Lepto is only one
- Prevention of disease
- Aid in disease prevention
- Aid in disease control
- Other
- pathogen shedding reduction
Modified live (attenuated)
advantages
- strong and long-acting immunity
- effective intranasal and orally
- less risk hypersensitivity
- may stimulate interferon
- humoral and CMI
Modified live (attenuated)
Disadvantages
- mild systemic rxns occur
- risk reversion to virulence
- perpetuation of antigen in pop
- abortion (depending on virus)
- limited shelf life
Killed (inactivated) vaccines
Advantages
- unlikely to cause dz
- stable in storage
Killed (inactivated) vaccines
Disadvantages
- incomplete inactivation
- short-lived immunity
- only parenteral route
- hypersensitivity
- adjuvants => local reactions
booster importance
- follow label directions
- yearly booster recommended for MVL and killed
- killed vaccines require booster before protection complete
Responses to Killed vaccines
- 1st administration => primary response
- short lived
- weak response
- predominant antibody is IgM
- 2nd administration => anamnestic response
- stronger response
- longer lived
- predominant antibody is IgG
- more memory
Booster vaccination failure
- booster given too early
- anamnestic response doesn’t occur
- too much time elapse before booster
- booster acts as primary response
modified live response
- virus or bacteria grows in animal
- don’t need a booster
- stimulates primary and secondary response
purpose of adult herd vaccination program
- protect adult herd against high-prevalence or disastrous dz
- promote reproductive efficiency
Purpose of replacement herd vaccination program
- protect the calf against specific pathgens that are prevelant or would be disastrous
- prepare calf for entry into adult herd
multiple antigens
- Endotoxin load
- adults: max 3 gram-negative antigens
- young stock: max 2 gram-negative antigens
Minimum US dairy herd vacc program
- major viral dzs
- BVD (types 1 and 2)
- BHV-1
- BRSV
- P13
- at least one MLV for replacements prior to first breeding
- establishes strong baseline immunity
- 5 primary leptospira serovars
- major clostridial diseases
- core endotoxin vaccines
- brucellosis
Leptospirosis
- Host adapted: repro failure and abortion
- L. borgpetersenii serovar Hardjo, type hardjo-bovis
- L. interrogans serovar Pomona
- Non host adapted: acute dz
- L. kirshneri serova Grippotyphosa
- L. interrogans serovar Icterohaemorrhagiae
- L. interrogans serovar Canicola
*something about endemic in rats
*booster q 6 months I think
*classic example for concept of boostering
always give a particular vaccine at….
- particular site
- helps ID cause of vaccine reactions
On-going vaccination monitoring questions
- Are we vaccinating at the right time?
- Are we vaccinating against the right diseases?
- Are we meeting our goals for dz control?
*Stay current
dairy vacc protocol
incoming heifers
- IBR/BVD/P13/BRSV killed
- Clostridium 7-way
- E. Coli J5 K99
- Pinkeye (optional)
Tritrichomonus fetus
- don’t use in bulls
- lives in fornix of prepuce of bulls (no good immune resp)
Brucella
- don’t vaccinate a bull
- because then they will be positive
vaccination trouble-shooting
- fridge working
- handling
- timing, site,
