Smallpox vs. Chickenpox – Comparison & Differences

Smallpox and Chickenpox are both viral infections that can cause fever and rash. The variola virus causes smallpox and is very infective and causes death. On the other hand, Chickenpox is caused by the varicella-zoster virus and is less effective than Smallpox.

Main Difference

The mortality rate of Smallpox is higher than that of Chickenpox. In addition, the incubation period of Smallpox is almost 12-14 days, whereas the incubation period of Chickenpox is 10-21 days. Let us discuss the main differences between Smallpox and Chickenpox in detail.

Introduction of Smallpox

Smallpox is a highly effective viral infection, and the variola virus causes it. It is spread all over the body and causes illness and fever. Millions of death are happened due to this disease throughout human history. In addition, it was eradicated in 1980 through a global vaccination campaign. It affects the whole body, eventually to hands and feet.

Moreover, the spot becomes fluid-filled blusters and becomes pustules. The rash fall of a few weeks and bump left a mark on our body. It is spread to other infected persons, and its vaccination is practical and prevents the patient from the disease.


  • Fever
  • Rash
  • Headache
  • Backache
  • Small red spots on the body


  • Isolation prevents the spread of disease
  • Vaccination
  • Quarantine

Introduction to Chickenpox

Chickenpox is called varicella, and it is an effective viral infection. The varicella-zoster virus causes it. When it points out, t the rash in the face, chest, and back gradually spreads all over the body. In addition, it affects all ages and is most common in children. In the case of Chickenpox, it starts to appear with itchy red bumps.

Moreover, these bumps change into fluid-filled blisters, which gradually crust over and heal without scarring. The spots can last for many days to a week or more. The infected person is highly contagious during this time.


  • Headache
  • Fatigue
  • High fever
  • Rash


  • Isolation
  • Vaccination
  • Supportive care

Key differences between Smallpox and Chickenpox

  1. The variola virus causes smallpox, whereas the varicella-zoster virus causes Chickenpox.
  2. Smallpox is a more dangerous and deadly disease as compared to Chickenpox.
  3. The mortality rate is Smallpox is higher than Chickenpox.
  4. The incubation period of Smallpox is almost 12-14 days. On the other hand, the incubation period of Chickenpox is 10-21 days.
  5. Smallpox caused high fever, whereas Chickenpox caused a mild uproar.
  6. Smallpox leaves permanent scarring on the body, whereas Chickenpox does not leave permanent scars.
  7. Respiratory droplets transmit Smallpox. On the other hand, Chickenpox is spread through the air and affects the person.

Comparison Table

Features Smallpox Chickenpox
Incubation period 12-14 days 10-21 days
Morality rate Higher Less
Fever High fever Mild fever
Scarring Permanent scarring Not permanent scaring


They are cWe can conclude that Small Pox and Chicken Pox are different diseases. These diseases show deviations in their spreading, causative agents, and treatment techniques.

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