Can smallpox come back?

Naturally occurring smallpox has been eradicated, but the virus is stored in two secure laboratories. There is concern about potential bioterrorism, which is why vaccine stockpiles are maintained.

Is the smallpox vaccine still given?

Routine smallpox vaccination ended in the 1970s after eradication. The vaccine is now given only to certain military personnel, laboratory workers, and healthcare responders who might be exposed.

How deadly was smallpox?

Smallpox had a fatality rate of about 30% for variola major. It killed an estimated 300-500 million people in the 20th century alone before eradication.

InfectiousICD-10: B03Eradicated worldwide since 1980; no natural cases since 1977

Smallpox

Also known as: Variola, Variola major, Variola minor

Smallpox was a highly contagious and deadly viral disease caused by the variola virus, characterized by a distinctive progressive skin rash. It was declared eradicated by the World Health Organization in 1980 following a global vaccination campaign. Smallpox remains a concern as a potential bioterrorism agent, and stockpiles of the vaccine are maintained for emergency use.

Symptoms

High fever of 101-104°F (38.3-40°C)

Severe body aches and headache

Flat red spots that progress to raised bumps and then fluid-filled blisters

Rash appearing first on the face and then spreading to arms and legs

Lesions appearing in the mouth and throat

All lesions progressing at the same rate

Scabbing and scarring as lesions heal

Causes

Infection with the variola virus
Spread through respiratory droplets from face-to-face contact
Contact with contaminated bedding or clothing

Risk Factors

Lack of vaccination
Close contact with an infected individual
Exposure to the variola virus in a laboratory setting
Bioterrorism exposure scenario

Diagnosis

Clinical recognition of the characteristic rash pattern
PCR testing of vesicular fluid
Electron microscopy of lesion samples
Viral culture performed in high-containment laboratories

Treatment

Supportive care including fluids and fever management
Antiviral medications such as tecovirimat approved for smallpox
Vaccination within 3-4 days of exposure may prevent or lessen disease
Isolation to prevent spread to others

Prevention

Routine vaccination eradicated the disease globally
Smallpox vaccine stockpiles maintained for emergency use
Biosecurity measures to prevent release of the virus

When to See a Doctor

Any suspected exposure to smallpox as a medical and public health emergency
Development of a rash with progressive blisters after potential exposure
Fever and rash in the context of a known outbreak

Frequently Asked Questions

Related Conditions

Chickenpox

Infectious

Measles

Infectious

Shingles

Infectious

Have questions about Smallpox?

Ask Mother Nature AI for personalized, evidence-based guidance.

Ask about Smallpox

Medical Disclaimer: This content is for educational and informational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.

Content reviewed against peer-reviewed medical literature and clinical guidelines. Read our editorial standards.