Topic: Medical Diagnostic Imaging Tests


  • Creates 2D images

  • Uses radiation to product images

  • See bones and detect cancer & pneumonia

CT-scan : Computed Tomography Scan

  • Creates 3D images

  • Powerful than X-Ray

  • Primarily diagnosis of organs and soft tissue

  • Takes 360-degree image

MRI – Magnetic Resonance Imaging

  • Creates 3D image

  • Primarily used for spine, brain, neck, muscles, abdomen and breast

  • Creates cross section images

  • Uses radio waves and powerful magnet (People with metal implants, pacemakers or other implanted devices shouldn’t have an MRI)

Topic: Diseases

  • Bacterial – Tuberculosis, Diphtheria, Cholera, Bacterial Meningitis, Tetanus, Lyme disease, Gonorrhea, Botulism, Pertussis, Plague and Syphilis. 

  • Viral – Chickenpox, Flu (influenza), Herpes, Human immunodeficiency virus (HIV/AIDS), Human papillomavirus (HPV), Mumps, Measles, Rubella, Viral hepatitis, Dengue, Smallpox, Polio, Rabies, Trachoma, Nipah, Hantaviruses, Chikungunya, Human Enterovirus-71, SARS Coronavirus, Buffalopox, Crimean - Congo Virus, Ebola and Japanese Encephalitis 

  • Parasitic – Malaria , Filariasis

  • Fungal – Athlete’s foot, Ringworms, Candidiasis, Yeast infection

Topic: Vaccine and how do they work

Vaccines are used  to provide immunity against a disease causing pathogen (bacteria, virus, fungi or parasite).


How body naturally fights?

  • Each pathogen is made up of several subparts (called antigens), usually unique to that specific pathogen and the disease it causes. 

  • Body’s immune system  produces antibodies  in response to the pathogen’s antigen.

  • Each antibody in our system recognize one specific antigen and fights against it. We have thousands of different antibodies in our bodies.

  • Body’s immune system usually takes time to produce antibody against the specific antigen. 

  • Once the body produces antibodies in its primary response to an antigen, it also creates antibody-producing memory cells, which remain alive even after the pathogen is defeated by the antibodies.

  • When exposes to same pathogen in future, the antibody response is much faster and more effective because of the memory cells immediate response. 




  • It is a biological preparation that provides active acquired immunity to a particular infectious disease.

  • It contains an agent that resembles a disease-causing pathogen. The agent can be weakened or inactive parts of a particular organism (antigen) that triggers an immune response within the body.  Newer vaccines contain the blueprint for producing antigens rather than the antigen. 

  • When vaccine is introduced to body, the body will produce the antigen, this weakened version will not cause the disease in the person receiving the vaccine, but it will prompt their immune system to respond much as it would have on its first reaction to the actual pathogen.

  • Some vaccines require multiple doses, given weeks or months apart which allows for the production of long-lived antibodies and development of memory cells.

Herd Immunity - When a lot of people in a community are vaccinated the pathogen has a hard time circulating because most of the people it encounters are immune. This protects the people not vaccinated (vaccine allergic cases or HIV with weak immune system/cancer patients) to stay protected.


Random info:

  • Antigens are proteins, peptides (amino acid chains) and polysaccharides

  • The smallpox vaccine was invented in 1796 by English physician Edward Jenner  showcased the proper use of vaccination for first time.

  • An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects.

  • The science of vaccine development and production is termed vaccinology

  • Immunology is a branch of biology that covers the study of immune systems in all organisms. It charts, measures, and contextualizes the physiological functioning of the immune system in states of both health and diseases; malfunctions of the immune system in immunological disorders; and the physical, chemical, and physiological characteristics of the components of the immune system. 

Topic: Virus Mutation and Covid Delta Virus

Mutation - Mutations are changes in the genetic sequence, and they are a main cause of diversity among organisms.


Virus Mutation - Viruses manipulate host cells into building new viruses . As a virus replicates, its genes undergo random “copying errors” (i.e. genetic mutations). Over time, these genetic copying errors can, among other changes to the virus, lead to alterations in the virus' surface proteins or antigens.


Our immune system uses antigens to recognize and produce antibodies to fight the virus. When there is change in the antigen, there might or might not  be antibody for that particular antigen to fight the mutated virus. This puts body in a vulnerable stage.

Covid Delta Variant

  • lineage B.1.617.2

  • It was found in India

  • Major mutations - D614G (aspartic acid-to-glycine substitution) ; T478K (threonine-to-lysine substitution) ; L452R (leucine-to-arginine substitution) ; P681R (proline-to-arginine substitution)

  • hese mutations affect transmissibility of the virus and neutralization by antibodies.