Animal Health Lecture 5

Ultimate goal as animal health workers

disease prevention rather then waiting for it to happen and attempting to treat it

most effecitve way of disease prevention and control

Vaccination

Are vaccination and immunization synonyms?

No!

Immunization

the process by which an individuals immune system becomes fortified against a disease causing agent (pathogen) by various methods

Vaccination

A specific method of immunization

Involves the administration of a vaccine which is a biological preparation containing weakend, killed or inactivated forms of a pathogen or its components

Vaciation vs immunizaition

Immunization is the broader process of developing immunity against diseases, and vaccination is one of the methods used to acheive this goal

Important note about vaccinations

not all vaccinations of animals produce immunity

primary outcome of vaccination

is to stimulate the immune system to produce an immune response against the specific pathogen contained in the vaccine

Factors that account for the lack of an immune response to a vaccine (vaccination failure)

1. Health of the animal

2. Handling of the vaccine

3. Administration of the vaccine

Healthy vs sick animal and vaccinations

• A helathy animal under good management conditions (under minimal stress0 will respond positvely to vaccination with a robust immune response, producing memory cells (T and B cells) against future invasions by this specific pathogen

• A sick animal will produce a weak response to vaccination as all the bodys energy and resources are directed to deal with the stress/disease, rather then responding to the vaccine

Handling of a vaccine

• vaccines must be properly handed (storage and transported condtions) to avoid degrading the vaccine

  • Must be stored and transported at the recommended temperature and protected from light

What happens if a vaccine is handled poorly

will reduce/stop its ability to stimualte a proper immunte response in the animal

Administration of vaccine

Incorrect vaccine administration such as the wrong route or dosage can lead to vaccine failure

Most vaccines are injectable —> wrong injection location can result in a weak response and/or tissue damage

• why proper training of personnel is important to vaccination success

Importance of vaccination

important part of preventing and controlling many diseases

• successful vaccination programs increase the number of immune animals in the herd/flock and thus decreases the likelihood of a disease being able to start/spread

Limitations to vaccination

It is relative and can be compormised under a number of circumstances:

1. massive exposure to the infectious agent

2. exposure to a highly virulent strain of the infectious agent

3. animal is subjected to a disease or a stress factor (poor enoivment, managemnt, or nutrition)

Innate immunity (Natrual)

1. present from birth

2. provides immediate but general protection

3. includes physical and chemical barriers

4. include cellular immunity such as Neutrophils + Macrophages

Adaptive immunity (acquired)

1. develops over time based on body response to pathogens

2. highly specific

3. developed by disease exposure or vaccination

4. Involves T and B lymphocytes (memory cells)

Active acquired immunity

1. Acquired actively in response to an antigen (pathogen or vaccine)

2. Involves active immune response and memory cells

3. It develops over time & highly specific

4. Long term protection

Example of Active acquired immunity

Tetanus vaccine provides 1 year of protection

Passive acquired immunity

1. Acquired passively by receiving pre-formed antibodies or immune cells from another individual or an external source

2. It does not involve the receipents immune system produing an immune resposne or memory cells

3. Immediate & highly specific

4. Short term protection

Passive acquired immunity example

Antitetanic serum gives protection for 21 days

What is colostral immunity

the passive acquired immunity gained by mammals from colostrum

How can a neonate benefit from colostral antibodies

they must consume colostrum within 24-72 hours after birth

Problems with neonate not consuming colostrum

A neonate who didnt consume colostrum will be more prone to disease

A neonate wont consume colostrum due to a: weak mother, difficult birth, difficult nursing

A strestted neonate wont be able to absorb antibodies from colostrum

Failure in the development of passive immunity by colostrum will result in

1. Scours (Neonatal diarrhea is very dangrous)

2. Pneumonia (Neonates immunte system is not yet developed)

3. Neonatal mortality

What to do if a neonate fails to obtain colostrum

get ir from another mother of the same speciies living i nthe same envoirment

• some farms have what is called a colostrum bank

How to know if neonate got colostrum

there aer commercial tests avaible to test immunoglobulin (antibodies) levels in the neonate