Pharm: Vaccines Flashcards
Define immunity
- The ability of the human body to tolerate the presence of material indigenous to the body and to eliminate foreign material
- is specific to a single organism or group of closely related organisms
Define the immune response
- The development of defense against an antigen.
- Usually involves the production of protein molecules (antibodies or immunoglobulins) by B lymphocytes and the production of specific cells including T-lymphocytes whose purpose is to facilitate the elimination of foreign substances
Define Antigen
Antigens are foreign substances that can be either live (virus or bacteria) or inactivated that are capable of producing an immune response.
Define antibody
Antibodies are proteins produced by B lymphocytes to help eliminate an antigen.
Define passive immunity
- The transfer of antibody produced by one human or another animal to another. Provides immunity against some organisms but this protection is temporary.
- MC form is the antibodies an infant receives via the placenta from its mother in utero.
What is the duration of passive immunity?
Temporary, the antibodies degrade during a period of weeks to months
Define monoclonal antibodies
- Produced from a single clone of B cells, contain antibody to only one antigen or closely related group of antigens
- Many applications: diagnosis of certain types of cancer, tx of cancer, prevention of transplant rejection, treatment of autoimmune diseases, infectious disease treatment.
- Also used to treat RSV (Synagis)
- Do not interfere with the response to a live vaccine
Define active immunity
- Stimulation of the immune system to produce antigen-specific humoral and cellular immunity.
- From infection with disease-causing form of organisms or vaccination
What is the duration of active immunity effectiveness?
lasts many years, often a lifetime
Define immunologic memory
- The persistence of protection for many years after the infection is known
- Memory B cells continue to circulate in the blood (and reside in bone marrow) for many years
- Upon re-exposure, the memory B cells replicate and produce antibody very rapidly to reestablish protection
What do vaccinations produce?
- active immunity
- immunologic memory
List the two types of vaccines
- live attenuated
- inactivated
Live attenuated vaccines
- Produced by modifying a disease-producing (“wild”) virus or bacterium in a laboratory.
- Resulting vaccine organisms retains the ability to replicate and produce immunity but usually does not cause illness
Inactivated vaccines
- Composed of either whole viruses or bacteria or fractions of either
- Fractional: protein based or polysaccharide-based
- Protein based: toxoids and subunit or subviron products
- Polysaccharide: pure cell wall polysaccharide from bacteria
Identify the characteristics of live attenuated vaccines
- Must replicate in the vaccinated person, grows enough to stimulate an immune response.
- More sensitive – need to protect the vial (heat, light, etc.)
- If it does cause any symptoms, it is a much milder version than the natural disease, considered an adverse reaction
- Immune response is virtually identical to that produced by a natural infection
- Usually only need one dose
- May cause uncontrolled replication (severe or fatal) if administered to immunocompromised person.
- Can theoretically revert to original pathogenic form (has only happened with live, oral polio vaccine)
What vaccines are live attenuated vaccines
- Viral: MMR, vaccinia, varicella, zoster, yellow fever, rotavirus, influenza (intranasal)
- Bacterial: Oral typhoid
Identify the characteristics of inactivated vaccines
- Produced by growing the bacterium or virus in culture media, then inactivating it with heat and/or chemicals
- Not alive and cannot replicate
- Cannot cause disease from infection, even in immunodeficient person
- Less affected by circulating antibodies than live agents, can be given when antibody is present
- Require multiple doses
- First dose does not always provide protection but “primes” the immune system. The second or third dose → protective immunity.
What vaccines are inactivated whole cell vaccines
- Polio
- Hep A
- Rabies
Describe the purpose of a booster dose
Needed for inactivated vaccines bc the immune response is mostly humoral so little or no cellular immunity occurs. The additional dose boosts antibody titers
Define a fractional vaccine
- Inactivated vaccine
- The organism is further treated to purify only those compounds to be included in the vaccine
What are the fractional vaccines in the US
- Hep B
- influenza
- acellular pertussis
- HPV
- anthrax
- toxoids (diphtheria and tetanus)
Define a polysaccharide vaccine
Unique type of inactivated subunit vaccine composed of long chains of sugar molecules that make up the surface capsule of certain bacteria.