Immunity conferred by smallpox vaccineBMJ 2002; 324 doi: https://doi.org/10.1136/bmj.324.7346.1157/a (Published 11 May 2002) Cite this as: BMJ 2002;324:1157
How long does immunity last?
- Adam Jacobs (email@example.com), director
- Dianthus Medical Limited, London SW19 3TZ
- Division of Tropical Medicine, Liverpool School of Tropical Medicine, Liverpool L3 5QA
- Public Health Laboratory, Derriford Hospital, Plymouth PL6 8DH
- Worcestershire Acute Hospitals NHS Trust, Kidderminster Hospital, Kidderminster DY11 6RJ
- Bristol Public Health Laboratory, Bristol Royal Infirmary, Bristol BS2 8HW
EDITOR—I am disappointed that Beeching et al do not provide a reference for their statement that immunity conferred by smallpox vaccination fades after 10-20 years, or earlier in some people.1 After watching a recent BBC programme about smallpox2 I was curious to know whether the smallpox vaccination I had had in childhood would still protect me.
It has been remarkably difficult to find out. Information on the website of the Centers for Disease Control and Prevention says, “Most estimates suggest immunity from the vaccination lasts 3 to 5 years.”3 On the other hand, the World Health Organization's website says, “Anyone who has been vaccinated against smallpox … will have some level of protection. The vaccination may not still be fully effective, but it is …