natural and active immunity

infection

artificial and active immunity

vaccine

natural and passive immunity

maternal antibodies

passive and artificial

antibody transfer

under what circumstances would you use passive immunization?

an individual with an immune deficiency

toxin/venom with an intermediate threat to life

individuals with immune-deficiencies

why wouldn't use you use passive immunization?

it doesn't activate the immune system; it's just a buffer

anti-isotypic antibodies could cause problems

if the need is prophylactic

vaccination

intentional exposure to an altered pathogen; also referred to as inoculation

immunization

the process of eliciting a state of protective immunity against a pathogen

vaccine valency

polyvalent vaccines are designed to confer protection against multiple strains of pathogen

contraindications

a specific state in which treatment, surgery, drug, vaccine shouldn't be used because it could be unsafe for a particular individual

herd immunity

when the majority of the population is immune to an infectious agent, the potential reservoirs for the pathogen are reduced. the chances of that pathogen coming contact with susceptible individual are greatly reduced

morbidity

state of illness

mortality

death

immunogenicity

the ability to provoke an immune response

efficacy

the therapeutic effectiveness of a vaccine

safety

the presence or absence of adverse events

adverse event

an unfavorable or unintended manifestation of disease that is associated with administration of the drug (vaccine)

variolation

an early method of inoculating a person against smallpox by intentionally exposing them to the virus, either by scratching pus from a smallpox sore into the skin or by blowing dried scabs into the nose

vaccination

injection of cowpox rather than smallpox

cross-reactivity

Louis Pasteur expanded the work to other infectious diseases

smallpox is the only disease to be completely eradicated, because:

it evolves slowly, antigens are conserved

the vaccine is a live virus that establishes infection at the site of injection; it mimics the innate and adaptive response

smallpox is human-specific; no reservoirs in other species

what are the three major goals of vaccination?

safety

efficacy

sustainability/achievability in target populations

in general, what correlates with immune protection?

basic research and rational design are important to advance vaccine development

vaccine development begins with basic research to discover immunogens

identification of specific immune targets or correlates of immune protection are crucial for full development

what is meant by rational vaccine design?

original strategies for vaccine production included: isolate, inactive, inject

rational design allows us to factor the genetic sequence and structure of the pathogen into the design of the vaccine

reverse vaccinology is the use of knowledge of a pathogen's physiology and how it exploits our immune system

live attenuated vaccine

the pathogen is alive, but is attenuated

grown under sub-optimal conditions; the pathogen survives and reproduces but can't cause harm

pathogenicity is lost, but immunogencitiy is retained

MMR, chickenpox, smallpox, rotavirus

what are the benefits of live attenuated vaccines?

the initial response is strong, large quantities of immunogen are made

they require relatively few booster immunizations

some are attenuated in certain species, but not in others

some can be produced by growing the pathogen in abnormal culture conditions

some can be genetically engineered

what are the drawbacks of live attenuated vaccines?

potential mutation back to virulent form

risk of some disease-related complications

requires cold-chain

recombinant DNA technology can now be used to make them safer

inactivated or killed vaccines

the whole pathogen is killed or inactived

the pathogen structure are preserved, but the pathogen cannot replicate or become virulent again

polio, hepatitis A, flu, rabies

what are the benefits of killed vaccines?

safer

more stable

they often don't require a cold-chain

what are the drawbacks of killed vaccines?

now as robust of a response

because they don't replicate, they require large quantities

because they're dead, they can't penetrate host cells, endogenous response is severely diminished

what is a toxoid vaccine?

the disease may be due to an exotoxin secretion and not due to the pathogen itself

toxoids are exotoxins that have been chemically altered such that lost their pathogenicity but retain their immunogenicity

examples include diphtheria and tetanus

what are the benefits toxoid vaccine?

neutralizing antibodies bind to the toxin and render it harmless

what are the drawbacks of toxoid immunity?

only works on those pathogens that secrete toxins

purified protein subunit vaccination

recombinant DNA technology can be used to make protein subunits

that protein can then be part of the vaccine formulation

these vaccines are often referred to as 'acellular'

examples include hepatitis B, pertussis

what are benefits purified protein subunit vaccination?

the recombinant DNA can be manipulated such that mutation can be introduced

what are the drawbacks of purified protein subunit vaccines?

the development process can alter the epitope such that immunogenicity or stability might be compromised - that might alter the type or number of neutralizing antibodies involved

like heat-killed vaccines, these cannot get into cells and therefore there is a limited cell-mediated response

purified carbohydrate subunit vaccines

made from purified polysaccharides of pathogens

examples include pneumococcus, meningococcus

what are the benefits of purified carbohydrate subunit vaccines?

easy to purify, because there are a lot of them

very few side effects

what are drawbacks of purified carbohydrate subunit vaccines?

carbohydrates do not generate T-dependent B cell responses often require a hapten conjugate

recombinant vector vaccines

genes for key antigens are inserted into attenuated virus

the virus acts a vector for the antigenic genes which are expressed by host expression machinery

examples include COVID19, HIV, RSV, Zika

what are the benefits of recombinant vector vaccines?

all the benefits of attenuated vaccines

fewer risks - not using the actual pathogen, little chance of reversion

the characteristics of the vector can be advantageous

what are the risks of recombinant vaccines?

immune responses against the vector

similar to attenuated viruses, particularly stability problems

vaccine excipient

an inactive molecule that serves as a support or aid to the drug but has no direct therapeutic impact

preservatives

adjuvants

stabilizers

cell culture materials

inactivating ingredients

antibiotics

what is an adjuvant?

molecules included to enhance the immune response to a vaccine, while limiting the amount of antigen administered

they can increase the inflammatory response

they can enhance antigen presentation

they can increase antigen stability

what are liposomes?

microscopic, spherical vesicles made of one or more phospholipid bilayers that can enclose an aqueous core

what is a booster vaccine?

booster vaccination is required to achieve protective immunity to many pathogens

what is VAERS?

vaccine adverse event reporting system

contact your healthcare provider

report an adverse event using the VAERS online form or the downloadable PDF

what are therapeutic vaccines?

treatment rather than prevention

chronic infection

allergy

chronic inflammation

coronavirus

type of virus

SARS-CoV-2

the specific virus

COVID19

the named disease cause by infection of the virus

how does coronavirus infect us?

an infected individual expels virus laden droplets which are then inhaled by a second

the inhaled virus finds its way to the upper respiratory tract where it utilizes a receptor known as angiotensin-converting enzymes 2 to enter host cellsS protein of virus attaches to ACE2

once inside it hijacks the cell's machinery

further infection results in movement down the respiratory tract

what is herd immunity

when enough people in an area have immunity to a disease that it no longer spreads easily. it usually takes a large number of people getting vaccinated against or infected with the germ to achieve herd immunity

how do mRNA vaccines work?

mRNA vaccines teach our cells how to make a protein that will trigger an immune response inside our bodies

like all vaccines, they benefit people who get vaccinated giving them protection against diseases without risking the potential serious consequences newly available to the public