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.
What are the pure polysaccharide vaccines in the US
- Pneumococcal disease
- meningococcal diseae
- salmonella Typhi
Describe the type of immune response to a pure polysaccharide vaccine
- Typically T-cell independent which means they stimulate B cells without the assistance of T-helper cells.
- Antibody induced has less functional activity than those induced by protein antigens bc the predominant is IgM not IgG
Why are pure polysaccharide vaccines not administered to children under 2 year of age
Not consistently immunogenic in children 2 yo, probably due to immature immune system
True/false: there is a booster response to polysaccharide antigens
false
Explain the importance of conjugation of polysaccharide vaccines
Vaccine problems (doesn’t work <2 yo, less functional activity than other vaccines) can be overcome via conjugation, the polysaccharide is chemically combined with a protein molecule
Describe the immune response to a conjugated polysaccharide vaccine
Changes the immune response from T-cell independent to T-cell dependent
What are the conjugated polysaccharide vaccines in the US
- Hib
- pneumococcal disease
- meningococcal disease
Define recombinant vaccines
Made via genetic engineering technology
Describe the process of recombinant DNA in the production of a vaccine
Insertion of a segment of the viral gene into the gene of a yeast cell or virus which then produces the vaccine material
What are the recombinant vaccines in the US?
- Viral: Hep B, HPV, influenza, live attenuated influenza (replicates effectively in the mucosa of the nasopharynx but not the lungs
- Bacterial: Salmonella Typhi
Explain the purpose of the Advisory Committee on Immunization Practices
- Develop written recommendations on the use of vaccines licensed by the FDA for use in the civilian population of the US. Recommendations stand as public health guidance for safe use of vaccines and related biological products
- Produce two schedules: childhood and adolescent immunization schedule and the adult immunization schedule
- Recommendations sent to CDC
How often does the ACIP issue recommendations?
at least once a year
Influenza vaccine
- types
- age group
- Inactivated, fractional subunit
- Live attenuated (intranasal)
- Recombinant
- All people ≥ 6 months
Influenza vaccine
- indications
- dosing schedule
Indications:
- Everyone
- People at risk for influenza complication (young children, >50 yo, chronic conditions) should be given priority
Dosing schedule:
- Annual, recommended to get before end of October: flu season is November through Feb, but can last into May
Tetanus, diphtheria, acellular pertussis (Tdap)
- type of vaccine
- age group
- Acellular pertussis: inactivated, fractional subunit
- Diphtheria and tetanus: toxoids, inactivated vaccine
Age group: Adults
Tetanus, diphtheria, acellular pertussis (Tdap)
- indications/dosing schedule
- If have not received Tdap (or unknown), regardless of if have had TD
- Healthcare personnel of all ages
- All preg women 27-36 weeks (regardless of interval since last TD or Tdap)
- TD booster q 10 years after primary series
- Tdap can be given regardless of interval since previous TD
Measles, Mumps, Rubella
- type of vaccine
- age group
- live attenuated
- adults with no evidence of MMR immunity
Measles, Mumps, Rubella
- Indications
- Dosing schedule
Indications:
- Students at post-high school educational institutions
- International travelers
- Healthcare professionals
- Women of childbearing age who are not pregnant
- People who care for or around immunocompromised people
- People living with HIV without evidence of severe immunosuppression
Dosing schedule: One time dose
Varicella
- type of vaccine
- age group
- Live attenuated
- Adolescents and adults ≥ 13 yo
Varicella
- Indications
- Healthcare professionals
- People who care for or around immunocompromised people
- Teachers
- Child care workers
- Residents/staff in nursing homes and residential settings
- College students
- Inmates/staff of correctional institutions
- Military personnel
- Women of childbearing age who are not pregnant, should not get pregnant for one month after administration
- Adolescents and adults living with children
- International travelers
Varicella
- Dosing schedule
- 2 doses 4-8 weeks apart
- If it has been >8 weeks since the first dose, second dose may be given without restarting the schedule
Herpes Zoster
- type of vaccine
- Age group
Type of vaccine:
- Zostavax: live attenuated
- Shingrix: recombinant vaccine with an adjuvant (preferred by ACIP)
Age group:
- Zostavax: ≥ 60 yo
- Shingrix: ≥ 50 yo
Herpes Zoster
- indications
- Can get Zostavax if have had shingles, will help prevent future occurrences
- Can get Shingrix if have previously had shingles and/or Zostavax
- Both can be given regardless of chickenpox history
Herpes Zoster
- dosing schedule
- Zostavax: single IM dose
- Shingrix: 2 IM doses 2-6 months apart
Human papillomavirus vaccination
- type of vaccine
- age group
Type of vaccine: non-infectious recombinant vaccine.
- Gardasil 4 is a quadravalent
- Gardasil 9 is nine-valent ☺
Age group:
- Females 13-26
- Males 13-21
- Males 13-26 IF gay, bisexual, MSM, transgender, immunocompromised
Human papillomavirus vaccination
- dosing schedule
3 doses: 0, 1-2, 6 months (start between ages 13-26)
Pneumococcal vaccination
- type of vaccine
- age group
Type of vaccine:
- Prevnar 13: inactivated vaccine
- Pneumovax 23: inactivated subunit, polysaccharide vaccine
Age group:
- All adults ≥ 65
- Prevnar 13: people 2-64 with certain med conditions
- Pneumoax 23: people 2-64 with certain med conditions and people 19-64 who smoke cigarettes
Pneumococcal vaccination
- Dosing schedule
- Prevnar 13 first, then pneumovax 23
- Given another dose of pneumovax 23 if first dose was given before age 65 and 5 years have passed since previous dose.
- Good practice to tie to annual flu vaccine!
Hepatitis A
- type of vaccine
- Age group
- inactivated whole viral vaccine
- no age specified
Hepatitis A
- Indications
- Dosing schedule
Indications:
- Live in community with high rate of hep A
- MSM
- Street drug use
- Work or travel to countries with high rates of hep A
- Long-term liver disease
- Received whole blood products to help blood clot
- Work with HAV-infected animals or work with HAV in a research setting
Dosing schedule:
- 2 doses, 6-18 months apart
Hepatitis B
- Type of vaccine
- age group
Type of vaccine:
- Engerix-B: inactivated vaccine, fractional subunit
- Recombivax HB: recombinant vaccine
Age group: All adults
Hepatitis B
- indications
- dosing schedule
- All adults
- 3 doses, 0, 1, 6 month schedule
Meningococcal vaccination
- type of vaccine
- indications
inactivated subunit, conjugated polysaccharide
Indications
- Adults at risk for meningococcal infections during an outbreak (college, military, health care professionals)
- Those with anatomic or functional asplenia or persistent complement component deficiency
Haemophilus influenza type B vaccination
- type of vaccine
- age group
- inactivated subunit, conjugated polysaccharide
- all adults
Haemophilus influenza type B vaccination
- indications
- dosing schedule
- Not routinely recommended for healthy adults
- Is recommended for high risk: asplenia, recipients of hematopoietic stem cell transplant (HSCT), alcoholic, street drug use
- usually one dose (3 doses for HSCT)
