Skip Navigation
Explore our COVID-19 Resources and Updates
CHS blue logo square
 
 
Home > Our Work > All Publications > 2003

Publications

Our publications keep professionals working across the public, private, and academic sectors informed on the most important developments and issues in health security and biosecurity.

Find an article or report by keywords:

 
 
Find an article or report or see all by area, author, or year:

Title:

I was vaccinated against smallpox 40 years ago. Am I still protected?

Authors:
Gigi Kwik Gronvall
Date posted:
March 03, 2003
Publication type:
Article
Publication:

Scientific American Online 2003 Mar 3.

Publisher:
Nature America, Inc.
Availability:
Not available online
Introduction:

Edward Jenner, the English physician who first developed the smallpox vaccine in 1796, believed that vaccination caused a fundamental change in personal constitution and would lead to lifelong immunity to smallpox. Unfortunately, this proved to be incorrect. It is now clear that immunity wanes over time. Exactly how long the vaccine confers protection, however, is difficult to assess.

"Immunity to smallpox is believed to rest on the development of neutralizing antibodies, levels of which decline five to 10 years after vaccination. This has never been satisfactorily determined, though. And because smallpox has been eradicated in the wild, correlating antibody levels with susceptibility is not possible. Revisiting historical data is difficult because of incomplete information in a number of areas. These include how many times the subjects were vaccinated (revaccination produces longer-lasting immunity), whether the vaccinations were carried out successfully and whether or not subjects ever had a subclinical smallpox infection that would boost their immunity (this situation is particularly likely in endemic areas). The last natural smallpox infection occurred in 1977, so recent advances in immunology and medical testing cannot be brought to bear on this question.

 

 

Our Mission

To protect people’s health from epidemics and disasters and ensure that communities are resilient to major challenges.