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Immunity from smallpox vaccine persists for decades: a longitudinal study.
Dennis D Taub1, William B Ershler, Mark Janowski
1Laboratory of Immunology and Clinical Research Branch, National Institute on Aging-Intramural Research Program, National Institutes of Health, Baltimore, MD 21224-6825, USA.
The American Journal of Medicine
|November 26, 2008
Summary
Smallpox vaccination provides lifelong immunity, with antibody titers remaining high for up to 88 years. Prior vaccination or infection ensures sustained vaccinia-specific antibody responses, suggesting boosters are not essential.
Area of Science:
- Immunology
- Vaccinology
- Epidemiology
Background:
- Bioterrorism concerns necessitate evaluating current population immunity to smallpox.
- Understanding the longevity of vaccine-induced immunity is crucial for public health preparedness.
Purpose of the Study:
- To assess the magnitude and duration of antiviral antibody immunity following smallpox vaccination.
- To determine if age or multiple vaccinations impact long-term antibody titers.
Main Methods:
- Analysis of serum samples from 246 participants in the Baltimore Longitudinal Study of Aging.
- Quantification of vaccinia-specific IgG and neutralizing antibody titers in individuals vaccinated 13-88 years prior.
- Inclusion of subjects with documented smallpox infection and unvaccinated controls.
Main Results:
- Vaccinated individuals maintained high antivaccinia antibody titers indefinitely.
- No significant decrease in antibody titers was observed with age over an 88-year follow-up.
- Individuals with prior smallpox infection showed similar antibody levels to vaccinated subjects.
Conclusions:
- Smallpox vaccination confers long-lasting immunity, with antibody responses sustained over decades.
- Neither multiple vaccinations nor recent boosters appear necessary for maintaining immunity.
- Vaccine resources should prioritize unvaccinated individuals due to the enduring nature of existing immunity.
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