Speaker: Dr. Ethan Blocher-Smith
The talk will include characteristics, actions, mechanisms, and effects of viruses.
Our speaker is a DO with IU Health Primary Care - Fishers South.
Sponsored by Alan Schmidt
Program: Virology 101/102
Speaker: Ethan Blocher-Smith, DO, family practice, IU Health - Fishers
Introduced By: Alan Schmidt
Attendance: NESC: 85; Zoom: 32
Guest(s): Geoff McLuen (?), Nanditz Pushpala
Scribe: Alan Schmidt
Editor: Carl Warner
Talk’s Zoom recording found at: https://www.scientechclubvideos.org/zoom/12012025.mp4
Our speaker, Dr. Ethan Blocher-Smith, has a BS from Huntington College, a MS in biochemistry from IUPUI, and a Doctor of Osteopathy from Marian University. He has passion for chemistry and medicine and is presently a primary care physician at IU Health in Fishers. His talk described the characteristics, actions, mechanisms, and effects of viruses.
What is a Virus?
Viruses have an outer shell (capsid) that contains genetic information (DNA or RNA) that fuses with cells, but are not alive. They lack their own manufacturing mechanisms and rely on hijacking host cells. Binding proteins (like spike proteins) on the capsid allow viruses to enter host cells.
How Does a Virus Work?
A virus must enter a healthy host by binding to specific cell surface proteins. The virus then uses the host cell to replicate. Upon replicating, it exits the host cell to spread further.
Why Are There So Many Different Viruses?
Viruses are classified by the Baltimore system (e.g., herpes, HPV, poxvirus, parvovirus, rotavirus, polio, common cold, influenza, rabies, HIV, hepatitis). High diversity is due to different genetic materials and replication strategies.
Influenza as a Case Study
There are four main branches for influenza: A, B, C, D. Influenza A and B use hemagglutinin (HA) and neuraminidase (NA) to bind cells. Flu A has 18 HA and 11 NA variants (e.g., H5N3). Flu B maintains stable HA/NA genes by lineage. Viral recombination leads to new strains. Viral transmission involves wild birds, ducks, mink, pigs, poultry, horses, dogs, and cat hosts.
How Do We Stop Viruses?
Antiviral drugs like oseltamivir, amantadine for influenza; entry blockers, NRTI/NNRTI, integrase blockers, protease inhibitors, capsid inhibitors for HIV are used to inhibit viral entry and/or replication.
Vaccinations are crucial for prevention. Vaccines can be derived from inactivated or live attenuated viruses. Subunit vaccines contain a portion of the virus; the portion of the organism selected is the part needed to produce a protective immune response. A viral vector vaccine is a vaccine that uses a viral vector to deliver genetic material (DNA) that can be transcribed by the recipient's host cells as mRNA coding for a desired protein, or antigen, to elicit an immune response. Toxoids are altered forms of toxins; in this case think weakened with immunogenicity maintained causing an immune response but not the disease from the associated bacterium. Remember, a hot virus from the rainforest lives within a 24-hour plane flight from every city on earth. Editor’s Note: This paragraph has been fleshed-out with online information.
The Future of Virology
Gene Editing via Viral Vectors
Viruses are increasingly used as delivery vehicles for gene therapy, allowing precise editing or replacement of faulty genes in human cells.
FDA-Approved Cellular and Gene Therapy Products
The presentation listed numerous therapies approved by the FDA, reflecting rapid growth in gene and cell therapy. Examples include CAR-T cell therapies (e.g., KYMRIAH, YESCARTA), gene therapies for hemophilia (e.g., HEMGENIX), and treatments for spinal muscular atrophy (e.g., ZOLGENSMA).
Global Health
Worldwide approved gene therapies based on viral vectors.
Ethan Blocher-Smith
