Virus Biology and How the COVID 19 Vaccine Works - An Interview with Jingyou Yu, Ph.D. [Part 2]

Read the article here:


The development of the Johnson and Johnson vaccine:    • Видео  
Vaccine hesitancy:    • Vaccine Hesitancy - An Interview with...  

An interview with Dr. Joseph Betancourt on Vaccine Distribution:    • Massachusetts General Hospital and th...  


COVID-19 Vaccine Information from Massachusetts General Hospital: https://www.massgeneral.org/news/coro...


Check out our website for more information, news articles, and upcoming events: sitn.hms.harvard.edu/seminar-series/



--------


Glossary



ACE2: A protein present on some human cells. The SARS-CoV-2 spike protein binds to ACE2.


Ad26: An adenovirus subtype used in the Johnson & Johnson COVID-19 vaccine. This vaccine uses the Ad26 virus to deliver DNA into human cells that are then used by the cells to create the SARS-CoV-2 spike protein. This triggers a non-infectious immune response. DNA delivered by the virus does not get integrated into a person’s DNA and degrades over time.


Adenovirus: A type of virus that can cause the common cold. The Johnson & Johnson COVID-19 vaccine repurposes this type of virus.


Antibody: A protein that recognizes and binds to an antigen. When antibodies bind to the spike protein of SARS-CoV-2, the spike protein can no longer be used by the virus to enter human cells. Prior exposures to antigens, such as through vaccinations, generate not just more antibodies, but also more specific antibodies. Antibodies can be found in a variety of places, including in the bloodstream, the gut, and the lungs. Antibodies are responsible for the humoral immune response.


Antigen: Any molecular structure that can be recognized by an antibody.



Chimeric virus: A virus that has been modified; for example, a virus that has been modified to not cause disease and to instruct human cells to produce the SARS-CoV-2 spike protein.


Host cell: A cell that is part of the human body. Host cells make up you and me. When the body is infected by a virus, host cells may become infected and host the virus.


Immunogen: Any molecule that triggers an immune response. This can be anything from the spike protein of SARS-CoV-2 to a molecule that forms part of a bacteria’s cell membrane.


Immunogenic: Describes the degree to which a vaccine can generate an immune response. Vaccines that are more immunogenic generate a stronger and longer-lasting immune response.


Nucleic acid: A class of molecules that include the molecules that make up DNA and mRNA. Human cells can use DNA as a template for making mRNA and, in turn, use mRNA as a template for making proteins. In the case of mRNA vaccines for COVID-19 (such as ones from Pfizer and Moderna), the mRNA delivered by the vaccine instructs human cells to make non-infectious spike proteins. The immune system can recognize these spike proteins and prepare beforehand for a potential real infection. mRNA also does not integrate into a person’s DNA and degrades over time.


Pathogen: Anything that causes disease, including certain viruses, bacteria, and fungi.


Receptor: Any protein on a cell’s surface that can interact with other molecules. In the case of COVID-19, SARS-CoV-2’s spike protein recognizes and binds to the ACE2 receptor on human cells, which allows the virus to enter human cells.


Replication incompetent: Describes a virus that has had certain genes removed such that it cannot replicate anymore and cannot cause disease in humans.


SARS-CoV-2: The virus that causes COVID-19.


Spike protein (also called S protein): A special protein on the surface of the SARS-CoV-2 virus that can recognize and bind to molecules on human cells. This binding interaction enables the virus to enter human cells and cause disease. Vaccines work, in part, by stimulating the production of antibodies that target the spike protein. Due to its resemblance with a crown, the spike protein gives the coronavirus its name.


T cell: A type of immune cell that constantly circulates in the bloodstream. Some T cells recognize viral antigens present on the surface of self-cells, which triggers the T cell to kill virus-infected self-cells. Together with B cells, which produce antibodies, they are the primary way by which the immune system responds more quickly to future infections with the same pathogen. T cells are responsible for the cellular immune response.