Medical Interventions Q2 Quiz 1

Live attenuated

• Made from living viruses or bacteria that are weakened. Most likely will get a fever from this one

  • MMRr, mumps, measles, rabies

Inactivated

• Killed or inactivated version of virus. Inactivated by heat or chemicals

  • Immune response is weaker, and it requires boosters

  • Polio vaccine, Hep A

  • Smaller amount of antibodies is made

Toxoid

• A toxin from the bacteria or virus is added into the vaccine to trigger an immune reaction instead of the actual virus/bacteria.

  • Tetanus, diptherin

Subunit and Conjugate

• Specific purified piece of pathogen (protein, sugar, inactive toxins)

  • Fewer side effects

  • Hep B, HPV, Pneumococcal, HIB (Influenza type B. Weaker version)

Viral Vector

• AstraZeneca used this method. Employs a harmless viral vector to shuttle the genetic instructions into the host cell

  • Ebola

MRNA Vaccine

• MRNA Vaccine → Instructs the cell to produce viral protein directly. Later destroyed by body

  • COVID, moderna, pfizer.

Naked DNA Vaccine

• HIV is a genetic vaccine that delivers a small, circular piece of DNA (a plasmid) directly into the body's cells, usually through injection into muscle. This plasmid contains a gene that encodes a protein specific to a particular pathogen, which the body's cells then read and produce. This triggers an immune response against that protein without the use of an infectious virus or carrier molecule

Similar Pathogen Vaccine

• A pathogen similar to the target pathogen is collected and turned into a vaccine. 

  • Smallpox from cowpox

Genetic Engineering

•  Direct manipulation of genes for practical purposes

Ligase Enzymes

• Joins two molecules by forming a new chemical bond. Glues DNA together. Phosphodiester bond between 5’ phosphate and 3’ hydroxyl ends. Seals gaps between sticky ends. 

Recombinant DNA

• Recombinant DNA (rDNA) technology is a biotechnology process that creates DNA molecules by combining genetic material from different sources.  Insert a gene of interest into an organism's genome which can be used to produce desired characteristics

Restriction enzymes

They are enzymes that cut specific bases (recognition/target site) and creates sticky ends that allow DNA fragments to be easily inserted into another piece of DNA.

Effective vaccines

Long shelf life, one dose is enough, low level of side effects or toxicity, stimulate immune cells (T and B). Easy to administer, long term effects, protects from wild and natural pathogen. 

Plasmid

Small, circular DNA that replicates independently of the main chromosome. Had accessory genes. Can be ring shaped I guess.

Routes of administration

Injection and oral for some specific vaccines

Intramuscular

Most common form of vaccination injection. Injected into the muscle because the muscle gives a better immune response, rapid absorption, and a rich blood supply. High concentration of APCs (antigen-presenting cells). 

Subcutaneous injection

Added through the fatty layer of skin

Intradermal

Into the dermis, under the epidermis, slow absorption. Bubble may form where it was given (allergic reaction tests)

Oral vaccine

Polio, rotovirus, cholera

Steps of Viral Vaccine Production With a Bacterial Plasmid

1. Restriction enzymes recognize specific DNA sequences to cut. Some restriction enzymes cut jagged sticky ends, for recombinant DNA, and some make clean cuts called blunt ends. They take a specific gene of interest

2. Input gene of interest into a plasmid so that it creates a protein of interest. Do this by cutting plasmid circle with same restriction enzyme and inserting gene

3. DNA ligase joins the gene and the plasmid together 

4. Plasmid is inserted into a cell as a vector and the cell starts producing the protein from the gene 

Self Ligation

Plasmid ligates back onto itself without the gene segment (glues back to normal)

Inversion

When the gene is ligrated in backwards