Preventative Medicine - Immunizations Part 1

What is the primary function of the immune system?

It is the body's defense against infection.

What triggers the cells in the immune system to act?

An antigen or allergen.

What is the action of the immune system when triggered by an antigen or allergen?

To destroy the foreign substance and clear it from the body.

What are the two main types of immunity mentioned?

Humoral and cellular immunity.

What constitutes the body's first line of defense?

Skin, mucous membranes, cilia, stomach acid, and urine flow.

What cells are part of the second line of defense?

DC cell, Macrophage, Monocyte, Neutrophil, Basophil, Eosinophil, Mast cell, NK cell, γδ T cell, and NKT cells.

What cells are part of the third line of defense?

CD4+ T cell, CD8+ T cell, and B cell.

What are the key organs and structures of the immune system shown in the diagram?

Thymus, spleen, lymph nodes, bone marrow, and lymph vessels.

What do B cells mature into and what do they secrete?

They mature into plasma cells and secrete antibodies, which are immunoglobulins (IgM (acute), IgA (membranes), IgE (allergies), IgD, IgG (chronic)).

What is the function of Cytotoxic T cells (CD8+)?

They attach to antigens on the cell surface and directly kill the antigen.

What do Cytotoxic T cells (CD8+) secrete?

Cytokines, such as interferons and interleukins.

What is the role of Helper T cells (CD4+)?

They assist B cells and T cells.

What is the function of Suppressor T cells (Tregs)?

They inhibit B and T cells.

What role does the Complement System play in immunity?

It helps antibodies kill antigens.

What is the function of Dendritic Cells?

They are antigen-presenting cells.

What process activates a B cell?

Antigens binding to the B cell.

What does an activated B cell mature into?

A plasma cell.

What do plasma cells produce?

Immunoglobulins (antibodies).

What are the five types of immunoglobulins (antibodies) shown?

IgG, IgE, IgD, IgM, and IgA.

What is the function of macrophages?

They are white blood cells (WBCs) that engulf germs and degraded cells.

What type of cell produces antibodies?

B-lymphocytes.

What is the function of antibodies?

They bind to antigens to form antigen-antibody complexes and mark cells for destruction.

What is the role of T-lymphocytes?

They are defensive white blood cells that attack cells that have already been infected.

What happens when B cells bind to an antigen?

It signals other cells to help the immune response.

How long does it take for the body to mount an initial immune response the first time it encounters an antigen?

Several days.

What is created during the initial immune response to an antigen?

Memory cells and antibodies.

What is the advantage of having memory cells and antibodies?

They allow the immune system to mount a fast response the next time that specific antigen is encountered.

How do vaccines develop immunity?

By imitating an infection.

Does a vaccine cause the illness it is designed to prevent?

No, but it does invoke the immune system to produce T-lymphocytes and/or antibodies.

What is responsible for the minor symptoms like malaise and low-grade fever after vaccination?

The immune system's response to the vaccine.

How long does it typically take for the body to produce T-lymphocytes and B-lymphocytes (antibodies) after vaccination?

A few weeks.

Is it possible to get a disease even after being recently vaccinated for it?

Yes, if a patient is exposed to the illness shortly after vaccination before the body has had time to produce an immune response.

What is active immunity?

A type of immunity where the body develops its own antibodies through B-cell proliferation and T-cell sensitization.

What are the characteristics of the immune response in active immunity?

It is a durable response.

Is active immunity permanent?

It is less likely to wane over time but may still require boosters.

How do the majority of vaccines work?

By inducing active immunity.

What is passive immunity?

A type of immunity where antibodies made by another organism are transferred or given to another person.

What is an example of natural passive immunity?

Maternal antibodies passed through the placenta and breast milk to a baby.

Are memory cells created in passive immunity?

No.

What is the duration of the immune response in passive immunity?

It is a temporary immune response.

Under what circumstances is a globulin product administered for passive immunity?

For a specific exposure, typically to immunocompromised patients who cannot mount an effective immune response.

When can passive immunity be given to a non-immunocompromised person?

When they are exposed to a serious illness for which an immunoglobulin is available.

What are some examples of illnesses where immunoglobulin can be given for passive immunity?

Rabies, hepatitis B, tetanus, and varicella (for those not previously vaccinated).

What is an antitoxin?

A heterologous hyperimmune serum produced in animals, usually horses, containing antibodies against only one antigen.

What diseases are treated with antitoxins?

Botulism and diphtheria.

What other product utilizes antitoxins?

Anti-venoms.

What is a potential complication of using antitoxins derived from horses?

Serum sickness, which is an immune reaction to the horse protein.

What are monoclonal antibodies?

Antibodies produced from a single clone of B cells, containing antibody to only one antigen or a closely related group of antigens.

What infectious agents can be prevented using monoclonal antibodies?

Respiratory syncytial virus (RSV) infection, Anthrax, and Ebola.

What are some other uses for monoclonal antibodies besides preventing infectious agents?

Diagnosis and therapy of certain cancers, autoimmune diseases, asthma, allergies, eczema, lowering cholesterol, Crohn's disease, migraine prevention, and prevention of transplant rejection.

What specific cancers are treated with monoclonal antibodies?

Breast, colorectal, lung, bladder, multiple myeloma, leukemia, lymphoma, and melanoma.

What specific autoimmune diseases are treated with monoclonal antibodies?

Rheumatoid arthritis (RA), multiple sclerosis (MS), psoriasis, and systemic lupus erythematosus (SLE).

What are the different types of vaccines?

Live, attenuated; Inactivated (killed); Subunit (toxoid); Conjugated; DNA/mRNA; Recombinant DNA technology (RDT).

For what types of infections are live, attenuated vaccines mostly used?

Mostly for viral but some bacterial infections.

What does "avirulent" mean in the context of live, attenuated vaccines?

The organism is modified so that it cannot cause disease in the host.

How does a whole-cell live, attenuated vaccine stimulate the immune system?

It stimulates a normal immune response, both cellular and humoral.

What is the major advantage of live, attenuated vaccines in terms of immunity?

They create the longest immune response, providing the best immunity, often lifelong with 1-2 doses.

What is a potential risk of live, attenuated vaccines?

They have the potential to mutate and become virulent, although this is rare (only documented with oral polio).

Who is at risk of illness from a live, attenuated vaccine?

Immunocompromised persons.

How can the antigen from a live, attenuated vaccine be spread?

It can be excreted in feces.

What is a potential contamination risk during the manufacturing of live, attenuated vaccines?

Other viruses can contaminate the cell culture.

What are some disadvantages of live, attenuated vaccines?

Severe reactions are possible, the vaccine is fragile requiring careful handling and storage, and the development stage is very long.

What are some examples of live, attenuated vaccines?

- Measles, mumps, rubella (MMR)

- Varicella (Chicken-pox)

- Yellow fever

- Rotavirus

- Intranasal influenza.

What are the main contraindications for live, attenuated vaccines?

Immunocompromised patients and pregnancy.

What is the guideline for administering immunoglobulin and live, attenuated vaccines?

They must be separated.

If immunoglobulin is given first, how long should one wait before giving a live, attenuated vaccine?

At least 3 months.

If a live, attenuated vaccine is given first, how long must one wait before giving immunoglobulin?

At least 2 weeks.

What is the rule for administering more than one live, attenuated injected vaccine at the same time?

They can be given together OR you must wait at least 4 weeks between them.

How are inactivated vaccines made?

The bacteria or virus is killed with radiation, heat, or chemicals.

Can inactivated vaccines cause disease?

No, they cannot cause disease, even in immunocompromised patients.

What type of immune response do inactivated vaccines primarily produce?

A humoral response.

What is a key requirement for the dosing of inactivated vaccines?

They always require multiple doses.

What can happen to the antibodies from an inactivated vaccine over time?

They can diminish.

What are some examples of inactivated vaccines?

- Polio

- rabies

- hepatitis A

- influenza.

What part of the pathogen is used to make subunit vaccines?

A part of the virus, bacteria, or toxin.

What do subunit vaccines contain?

Only the essential antigens.

What is a major advantage of subunit vaccines regarding side effects?

Side effects are very minimal.

What is often required after an initial subunit vaccination?

A booster vaccine.

What are some examples of subunit vaccines?

- pertussis (whooping cough)

- hepatitis B

- human papillomavirus

- herpes zoster.

What is an advantage of subunit vaccines in terms of production?

They are easy to manufacture.

How are subunit vaccines made?

Proteins are isolated, purified, and added to an adjuvant.

What is an adjuvant?

An immune stimulant required to boost the immune response.

What can the adjuvant in a subunit vaccine cause?

Side effects like low-grade fever, malaise, and myalgias.

How do certain diseases cause illness through bacteria?

The bacteria produces a toxin.

What are the weakened toxins used in toxoid vaccines called?

Toxoids.

How do toxoid vaccines work?

The vaccine helps the immune system fight the toxin, not the bacteria itself.

What is a requirement for toxoid vaccines to maintain immunity?

They require a booster vaccine.

What are two examples of toxoid vaccines?

Diphtheria and tetanus.

What is the challenge that some bacteria present to the immune system?

Their antigens are covered with a sugar-like substance called polysaccharides, making it difficult for the immune system to recognize the antigen.

Under what other circumstances can conjugate vaccines be used?

When an antigen is not soluble or is very small.

How do conjugate vaccines work?

A specific antigen is combined with another molecule, usually a sugar or other peptide.

What is the effect of the conjugation process?

The immune system can recognize the antigen easier and form immunity.

What are some examples of conjugate vaccines?

- Pneumococcal

- Meningococcal

- Haemophilus influenzae type B (Hib) vaccines.

What is messenger RNA (mRNA)?

A type of RNA necessary for protein production that uses information in genes to create a blueprint for making proteins.

What happens to mRNA in a cell after a protein is made?

The cell quickly breaks it down.

How do mRNA vaccines work?

They introduce a piece of mRNA that corresponds to a viral protein, which the cell then uses to produce the foreign protein, triggering an immune response.

Where does the mRNA need to go inside the cell to work?

It needs to cross the cell wall and enter the cytoplasm.

What does the immune system produce in response to the foreign viral protein made by the cells?

Antibodies.

How do the antibodies produced from an mRNA vaccine protect the body?

They recognize individual viruses, attach to them, and mark them for destruction.

Do mRNA vaccines use a live virus?

No.