Table of contents

1. Introduction to Microbiology3h 21m
2. Disproving Spontaneous Generation1h 18m
3. Chemical Principles of Microbiology3h 38m
4. Water1h 28m
5. Molecules of Microbiology2h 23m
6. Cell Membrane & Transport3h 28m
7. Prokaryotic Cell Structures & Functions5h 52m
8. Eukaryotic Cell Structures & Functions2h 18m
9. Microscopes2h 46m
10. Dynamics of Microbial Growth4h 36m
11. Controlling Microbial Growth4h 10m
12. Microbial Metabolism5h 16m
13. Photosynthesis2h 31m
14. DNA Replication2h 25m
15. Central Dogma & Gene Regulation7h 14m
16. Microbial Genetics4h 44m
17. Biotechnology3h 0m
18. Viruses, Viroids, & Prions4h 56m
19. Innate Immunity7h 15m
20. Adaptive Immunity7h 14m
21. Principles of Disease6h 57m

19. Innate Immunity

Physical Barriers in First-Line Defenses: Skin

Microbiology

19. Innate Immunity

Physical Barriers in First-Line Defenses: Skin

1:51 minutes

Problem 15.8aTortora - 14th Edition

Textbook Question

The earliest smallpox vaccines were infected tissue rubbed into the skin of a healthy
person. The recipient of such a vaccine usually developed a mild case of smallpox, recovered, and was immune thereafter. What is the most likely reason this vaccine did not kill more people?
a. Skin is the wrong portal of entry for smallpox.
b. The vaccine consisted of a mild form of the virus.
c. Smallpox is normally transmitted by skin-to-skin contact.
d. Smallpox is a virus.
e. The virus mutated.

Verified step by step guidance

Understand the historical context of smallpox vaccination, which involved variolation, a method where material from smallpox sores was introduced into the skin.

Consider the nature of the smallpox virus and how it typically infects individuals.

Evaluate the options given: a) Skin is the wrong portal of entry for smallpox, b) The vaccine consisted of a mild form of the virus, c) Smallpox is normally transmitted by skin-to-skin contact, d) Smallpox is a virus, e) The virus mutated.

Analyze why the method of introducing the virus through the skin might have resulted in a milder infection, leading to immunity without severe disease.

Conclude that the most likely reason the vaccine did not kill more people is related to the nature of the virus and the method of administration, focusing on the option that best explains the mildness of the infection.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Vaccination and Immune Response

Vaccination involves introducing a harmless form of a pathogen to stimulate the immune system. In the case of smallpox, the early vaccines used a mild form of the virus, which allowed the body to develop immunity without causing severe disease. This process helps the immune system recognize and combat the actual virus if encountered in the future.

Pathogen Characteristics

Understanding the characteristics of the smallpox virus is crucial. Smallpox is caused by the variola virus, which is highly infectious but can be effectively managed through vaccination. The mild form used in early vaccines did not cause severe illness, allowing for a safer immunization process.

Transmission Routes

The transmission of smallpox typically occurs through direct contact with infected individuals or contaminated objects. The fact that the vaccine was administered through the skin, rather than through respiratory routes, likely reduced the risk of widespread infection, as the virus was introduced in a controlled manner.