Smallpox is an infectious disease caused by the Variola virus. The initial symptoms of the disease include fever and vomiting, followed by formation of a skin rash and mouth sores. After a few days, the rash turns into bumps that scab over, which eventually fall off leaving a scars. Overall mortality after contracting the disease is 30%, with higher rates among infants. Smallpox can be easily spread through the contact with contaminated objects. The World Health Organization certified smallpox eradicated in 1980, as the last known natural occurring infection was diagnosed in 1977
Smallpox infection has had a major impact on human history and is highly dangerous in non-immunized populations. In the 1970s, vaccination against smallpox was discontinued in the U.S. However, smallpox remains a material threat to national security, and governments recognize the potential for accidental or intentional infection. There is broad consensus across the global public health and biodefense communities that there is a need for a stockpile of smallpox vaccine to mitigate risks of future disease outbreaks. The U.S. Strategic National Stockpile maintains a stock of approximately 300 million doses of smallpox vaccine that needs to be constantly refreshed with new vaccine to replace expiring vaccine. Further, there is an ongoing vaccination program of U.S. military personnel in the Global Response Force.
Countries worldwide maintain stockpiles of smallpox vaccine that must be refreshed over time. The importance of smallpox vaccines is reflected in the U.S. 2016 21st Century Cures Act, which recognizes the need for improved forms of biodefense, called "material threat medical countermeasures (MCMs)". Section 3086 of the Cures Act adds section 565A of the FD&C Act for FDA to establish a new priority review voucher (PRV) program for material threat MCMs Being able to provide safe and effective smallpox-preventing vaccines remains important and necessary for addressing and protecting public health. Current vaccinia vaccines have safety concerns and are associated with cardiotoxicity, limiting their ability to protect first responders or the public in case of need.1 A safer vaccine may allow for safer vaccine stockpiles, limiting cardiotoxic reactions in case of the need for vaccination either as part of military service, or to protect the public in the event of re-introduction of variola.