Vaccines

Introduction Veterinary biologics are products designed to prevent, treat, and even diagnose animal disease. They generally work by stimulating the body’s immune system to produce antibodies for fighting off infection.

Active Immunity Obtained when the individuals own immune system responds to an infectious disease Can be stimulated by either the disease itself or a vaccine

Passive Immunity Is obtained by receiving antibodies made by another individual’s immune system Most common example occurs when a lamb/kid consumes colostrum Over time, the maternal antibodies wear out, and the newborn must actively mount its own immune response It is essential to vaccinate at a young age

Vaccine Is a mixture of killed or modified microorganisms or their parts, administered to help prevent sickness from infectious diseases

Adjuvant A necessary component of inactivated vaccines They are additives to the vaccine suspension that help the body’s immune system recognize the dead virus particles and mount an effective immune response against them Aluminum salts are usually seen in commercial veterinary vaccines

Viral Vaccines 1.) Modified live virus vaccines 2.) Killed (inactivated) virus vaccines

Modified live virus vaccines (MLV vaccines) Composed of living viruses that have been altered to avoid causing the disease being vaccinated against These vaccines will still stimulate an immune response by the body Attenuation of these viruses is usually accomplished through repeated culturing of the virus in a tissue to which it is not adapted

Modified live virus vaccines (MLV vaccines) They don’t require the used of adjuvants Are less likely to produce vaccination reactions Stimulate a good immune response with fewer doses than a killed virus vaccine Some MLV vaccines have been known to cause the disease they are trying to prevent This happens when the attenuation process is not complete

Killed (inactivated) Virus Vaccines Composed of whole or parts of the killed virus which the body mounts an immune response Are more stable for storage Less likely to cause the disease being vaccinated against However, more likely to produce vaccination reactions due to the high level of virus particles and adjuvants that are used

Modified Live Vaccines Advantages Disadvantages One does required Faster immune response Stronger and more durable response Fewer post vaccination Reactions Not recommended for pregnant animals or animals in contact with pregnant animals Possible viral shedding to other animals Improper handling may inactivate the vaccine

Killed Virus Vaccines Recommended for pregnant animals Advantages Disadvantages Recommended for pregnant animals Stable in storage Multiple doses required Weaker immune response Shorter duration immune response Adjuvants may cause reactions Hypersensitivity reactions more common

Bacterial Vaccines Are killed whole bacteria or their parts Are among the most notorious for producing vaccination reactions Similar to the Killed Virus Vaccines they are unlikely to cause disease through retained virulence (ability to cause disease) More stable for storage

Toxoids An inactivated toxin (poison) Administered to stimulate the body’s immune response against the poison itself, rather than against the organism that produces it Most common is the tetanus toxoid Due to the delay in producing a response and because of their longer lasting effect, they are used in prevention rather than treatment

Antitoxin Is a purified serum from another individual, containing antibodies against a toxin Do not produce an immune response are not technically vaccines Provide immediate protection against a toxin and are given for treatment of existing disease, rather than for long-lasting prevention

Antitoxin Antitoxins that are used in veterinary medicine include Tetanus antitoxin Clostridium perfingens (foodborne illness) antitoxin Are a form of passive immunity

Antiserum Purified serum from another individual that contains antibodies against different organisms (bacteria or viruses)

Good practices Instruments used Administering the injections Vaccinating Good practices Instruments used Administering the injections

Vaccinating Vaccination of animals is not a complicated procedure. Requirements for vaccination include a good hypodermic syringe, a sharp needle, and fresh vaccine. Sterile techniques and some method of restraining the animal are also essential.

Vaccinating Syringes and needles need to be clean and sterile. Chemical disinfectants can inactivate modified live virus vaccines; therefore, livestock owners and veterinarians should avoid such chemical agents. Manufacturer’s directions should always be followed when administering a vaccine.

Vaccinating Vaccines can be administered in various locations on the animal’s body which include: Intradermal- the material is injected into the skin. Subcutaneous- the material is injected just under the skin. Intramuscular- the material is injected into large muscles, especially in the neck area. Intravenous- the material is injected into a vein for fast action

Vaccinating Most dosages of liquid materials for immunizations are measured in cubic centimeters, commonly referred to as “cc.” One cc is equivalent to one milliliter (ml). The temperature of materials injected and the syringes and needles used should be near, but not higher than, body temperature. Some injections, such as for serums, may be administered at body temperature or at a colder temperature.

Instruments Used There are various types of instruments that could be used to administer materials. The instrument used depends on the type of injection.

Syringes Syringes are the most common instrument used to inject liquid products into the body (other than orally or rectally). Several different types of syringes are available Sizes of syringes range from those that hold a few cc to those that hold several cc. Syringes are either metal, plastic, or glass. The most popular syringe is the plastic disposable type.

Needles Hypodermic needles are either disposable or reusable. A reusable needle is cleaned and sterilized before the next use.

Needles The gauge and length of the needle determine its size. The smaller the gauge number, the larger is the needle’s size. The length of a hypodermic needle is specified in inches.

Bevel refers to the angle of the needle opening.

Administering the Injections Producers commonly administer injections of various products as a convenient and accurate means of treating sick animals or administering vaccines, serums, and bacterins.

Intradermal Known as ID is made with a 20- to 16-gauge needle into the skin (and between two layers of skin). Evidence of an intradermal injection is a raised blister consisting of the injected material. The hair at the injection site is shaved before administering an intradermal injection.

Subcutaneous Known as Sub-Q are administered just under the skin may be made in areas over which the skin fits loosely, such as the neck or armpit. has a slow, but sustained absorption rate. The loose skin at the injection site is cleansed, then gathered and “tented.”

Subcutaneous The tented skin is where the needle is inserted and the syringe contents discharged. Following the injection, the area may be massaged to distribute the material.

Intramuscular Known as IM are made deeply into a large muscle (in front of the shoulder; neck). Cleanse the injection site and insert the needle into the muscle injection zone.

Intramuscular To ensure the needle injected into a muscle and not a vein, pull the syringe’s plunger just enough to verify that no blood flows into the syringe. Absorption of an IM injection is quick because of good blood supply at the injection site.

Intravenous Known as IV is made into a vein, where absorption is very quick. The jugular vein is a common site for intravenous injections.

Intravenous Jugular vein’s position is in a groove located from the back point of the jawbone at an angle to the point of the shoulder on either side of the neck. Applying pressure to this area with the thumb temporarily restricts the blood flow, and thus enlarges the vein to visible size.

Intravenous Clean the injection site with alcohol and insert the needle through the skin (at about a 30-degree angle) into the vein. After insertion of the needle, withdraw the plunger enough to apply suction to inspect for blood flow before allowing the medication to enter the bloodstream.

Intravenous The administration of IV medication is at a slow rate.