Prevention of smallpox includes:
- Smallpox vaccination
Currently, a smallpox vaccination is not part of a routine vaccination program because there have been no cases of smallpox since the worldwide vaccination program ended in 1977.
Smallpox vaccination provides high level immunity for 3 to 5 years and decreasing immunity thereafter. If a person is vaccinated again later, immunity lasts even longer.
Smallpox Vaccine Reactions
The vaccine is considered to be successful if it follows this natural progression:
- A red and itchy bump develops at the vaccine site in the first three or four days.
- In the first week, the bump becomes a large blister, fills with pus, and begins to drain.
- During the second week, the blister begins to dry up and a scab forms.
- The scab falls off in the third week, leaving a small scar.
Skin reactions after revaccination might be less pronounced with more rapid progression and healing than those after primary vaccinations. Revaccination is considered successful if a pustular lesion is present or an area of definite induration or congestion surrounding a central lesion (i.e., scab or ulcer) is visible upon examination 6 to 8 days after revaccination.
Continue to Smallpox Outlook
- Heymann DL. Smallpox containment updated: considerations for the 21st century. Int J Infect Dis. 2004 Oct;8 Suppl 2:S15-20. 
- Kerrod E, Geddes AM, Regan M, Leach S. Surveillance and control measures during smallpox outbreaks. Emerg Infect Dis. 2005 Feb;11(2):291-7. 
- Woods R, McCarthy T, Barry MA, Mahon B. Diagnosing smallpox: would you know it if you saw it? Biosecur Bioterror. 2004;2(3):157-63.