Protection from Smallpox: Beyond Immune Biomarkers

Abstract

Since the eradication of smallpox, immunological studies of smallpox vaccine (vaccinia virus) have provided great gains in understanding immunology as well as depecting smallpox vaccine-derived immune responses. Despite this wealth of knowledge, two confounding problems remain. First, that surviving smallpox provides an individual with lifelong protective immunity, whereas vaccination may not, and second, that specific molecular correlates of protection against smallpox remain vague. Historical literature on smallpox and contemporary studies of other human infections with orthopoxviruses, such as monkeypox, indicate that vaccination may lower disease risks, but it does not provide complete protection against infection in all individuals. Factors impacting protective immunity include longevity of immunologic memory post-vaccination, challenge dose and differences in the challenge viruses, as well as route of exposure. This article discusses historical information regarding smallpox attack rates during outbreaks and contemporary views on aspects of vaccines and naturally occurring orthopoxvirus outbreaks as related to vaccine-derived immunity.

Keywords:

• immune induction
• lifelong immunity
• monkeypox
• protective immunity
• smallpox
• vaccine

Acknowledgements

The authors would like to thank Dr Inger K Damon for her review of this manuscript.

Financial & competing interests disclosure

The views presented in this artcle are those of the authors and do not necessarily represent the views of the CDC. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.