Vaccines Flashcards
what was the first successful vaccine ?
cowpox virus was used to create the smallpox vaccine
what is active protection?
results when exposure to a disease organism or introduction of a killed or weakened form of the disease organism through vaccination where the protection is long lasting
what is passive protection?
when a person is given antibodies to a disease through antibody containing blood products rather than producing them
- protection is immediate, but short lived (few weeks)
explain how a more potent secondary immune response occurs
body is re-exposed to an antigen it has encountered before which causes a quicker response (3 days) and a higher level of response (more/better antibodies)
what is the time frame a primary antibody response takes and what antibody isotypes and affinities does it produce?
- 5-10 days
- usually IgM
- lower average affinity
what is the time frame a secondary antibody response takes and what antibody isotypes and affinities does it produce?
- 1-3 days
- increase in IgM and in some cases IgA or IgE
- higher average affinity
what are the 3 main ways vaccines are made?
- Attenuated (Weakened) Vaccines
- Inactivated (Killed) Vaccines
- Acellular (Subunit) Vaccines
explain how Acellular (Subunit) Vaccines are made and what is used
Use only specific components of the pathogen to trigger an immune response
- recombinant DNA
- conjugated polysaccaride
- peptide vaccine
- RNA vaccine
what is the vaccine RotaTeq
an attenuated live virus given by mouth for the rotavirus disease
what does rotavirus cause?
- leading cause of severe diarrhea in infants and young children
- can also cause fever, vomiting, and dehydration
what does Polio cause?
- muscle pain and paralysis of one or both legs or arms
- may also paralyze the muscles used to breathe and swallow. It can lead to death.
what are the two Polio vaccines and how are they administered?
- The IPV (inactivated poliovirus) vaccine, also called Salk’s vaccine, after Dr. Jonas
Salk is given 4 times as an injected shot and used in the U.S.A - Sabin vaccine is an attenuated poliovirus vaccine named after Dr. Albert Sabin. It is given orally and not used in the U.S.A.
what are the characteristics when the attenuated Polio vaccine (Sabin) is used?
- immune response is similar to a natural polio infection
- life long protection
- antibodies persist for 40 years
- contact immunity (indirect exposure can vaccinate others)
- easier to distribute due to being given orally
what is Hepatitis B?
disease of liver scarring and liver cancer caused by the hepatitis virus that spreads through contact with an infected person’s blood or by having sex with an infected person
what is the vaccine for Hepatitis B and how is it created?
- Recombivax HB: a non-infectious (protein) subunit viral vaccine
- a portion of the hepatitis B virus gene, coding for HBsAg, is cloned into yeast, and the vaccine is produced from cultures of this recombinant yeast strain
what is Pneumococcal pneumonia?
disease caused by Streptococci, begins with high fever, cough, and stabbing chest pains, bacteremia, meningitis, and death
what is the vaccine for Pneumococcal pneumonia?
Pneumococcal Conjugated Vaccines (PPV23) is a 23-valent polysaccharide
vaccine that, in some states, is mandated for children in daycare
how do conjugated vaccines work?
covalently attach weakly immunogenic antigens (carbohydrate) to a strongly immunogenic antigen (protein - carrier)
what is a 23-valent polysaccharide
vaccine?
23 polysaccharides of the bacterial capsule are attached to a carrier protein so a stronger antibody response can be elicited
what is meningococcal disease?
highly contagious, severe infection by the bacteria neisseria meningitides causing a blood stream infection called meningitis
what are the two meningococcal vaccines?
- meningococcal polysaccharide vaccine (MPSV4): recommended for high risk infants and children 2-10
- meningococcal conjugate vaccine (MCV4): recommended for all 11-12 yr olds, first year college student and military recruits
what is the DTaP vaccine used for ?
- combined protection for diphtheria, tetanus and pertussis
what is Diphtheria?
a disease that attacks the throat and heart where the bacteria produce a toxin that can lead to heart failure and death
what is tetanus?
also called “lockjaw” where the bacteria produce a toxin that can lead to severe
muscle spasms and death
what is pertussis?
also called “whooping cough” causes severe coughing that makes it hard to
breathe, eat and drink and can lead to pneumonia, convulsions, brain damage and death.
what does the aP part of the DTaP vaccine mean?
- “acellular pertussis”
- The acellular form is considered safer and contains far fewer antigens than the older inactivated whole cell, wP preparation, DTwP)
what is the MMR vaccine?
combined vaccine that protects against three viral infections, measles, mumps, and rubella
what does measles cause?
causes fever, rash, cough, runny nose, and watery eyes. It can also cause ear infections, pneumonia, brain swelling, and death.
what does mumps cause?
- causes fever, headache, and painful swelling of one or both of the major saliva glands.
- It can lead to meningitis and swelling of the testicles of boys or men, leading to infertility.
what does rubella cause?
- also called German measles
- It causes a slight fever, a rash, swelling of the glands in the neck, brain swelling, or bleeding.
- Infected in utero, it can cause miscarriage, blindness, deaf, or learning impairment.
what did S. Bernard hypothesize?
a link between exposure to thimerosal containing vaccines and neurodevelopmental disorders is biologically plausible, specifically in the MMR vaccines
what is Thimerosal?
was one of the most widely used preservatives in multi-dose vaccines to prevent microbial growth.
was S. Bernard’s hypothesis rejected?
yes
what are the side effects of vaccines?
- severe side effects are rare
- rare neurological side effects include seizures and Guillain-Barre syndrome
live vaccines should not be given to?
infants with known or suspected weakened immune systems
what are the different types of Covid-19 vaccines?
- non-replicating RNA or mRNA
- non-replicating DNA in vira vector
- protein subunit
- inactivated whole virus
what are the advantages and disadvantages of RNA vaccines?
- advantages: mRNA is a non-infectious, non-integrating platform, degraded by normal cellular processes; in vivo half-life can be regulated by making RNA more stable
- disadvantages: mRNA instability, high innate immunogenicity, inefficient in vivo delivery
what are the two types of RNA vaccines?
- non-replicating mRNA
- self amplifying mRNA
how are mRNA–LNP (Lipid Nanoparticle) delivered?
intramuscularly or intradermally.
what happens after the mRNA–LNP (Lipid Nanoparticle) are delivered into the body?
- double-stranded RNA (dsRNA) contaminants can form and, with the lipid nanoparticle (LNP) carrier, act as (PAMPs), which activate Toll-like receptors (TLRs) and trigger innate immune responses, including type I interferon (IFN) production.
in what cell types are mRNA vaccines translated into proteins?
all cell types, including professional antigen-presenting cells (APCs) like Dendritic Cells and Langerhans Cells
what happens once the mRNA vaccines are translated into proteins in APCs?
- T follicular helper (TFH) cells are activated in the germinal centers of lymph nodes
- TFH cells interact with B cells through the CD40-CD40L co-stimulatory receptor, and promote B cell survival, proliferation, differentiation, isotype switching and affinity maturation
what happens once the TFH cells with proteins produced from mRNA vaccines are presented by MHC I molecules?
strong CD8+ T cell responses are induced which are essential for killing infected cells and long-term immunity.
what is herd immunity (community immunity)?
When a critical portion of a community is immunized against a contagious disease, most community members are protected against that disease, even those who are not vaccinated get some protection
what does the threshold depend on to achieve herd immunity?
basic reproduction rate
- For instance, measles is highly infectious; the herd-immunity threshold is 92– 94% of the population. The threshold would be lower for a virus that is less infectious
what is the only vaccine against a disease not passed from one person to another?
tetanus
