On September 8, a Congressional exercise explored the implications of anthrax and smallpox attacks on the Korean Peninsula and the potential impact these attacks would have on Americans at home and abroad. This Congressional exercise allowed policymakers to learn and assess the types of decisions that would need to take place in the event of an outbreak.
At the beginning of July 2014, scientists discovered several vials of smallpox in an unused storage room in a Food and Drug Administration (FDA) laboratory located at the National Institutes of Health (NIH) in Bethesda, MD. The vials of smallpox were dated from the 1950s, and upon discovery were immediately secured. While testing determined that two of the six vials had viable smallpox virus, there was no evidence of any identified exposure risk to the lab workers or the public. Despite this recent discovery, the last officially acknowledged stocks of smallpox are held by the United States at the Centers for Disease Control and Prevention (CDC) and by Russia at the State Research Centre of Virology and Biotechnology.
Additionally, in May 2014, the World Health Organization (WHO) once again postponed a decision on the destruction of smallpox stocks held by the United States and Russia, and decided to set up a third WHO smallpox advisory committee in an attempt to determine consensus. The WHO’s advisory committee determined that the live smallpox virus was no longer needed to develop diagnostics and vaccines. However, the most compelling reason for long term retention of live smallpox stocks is their role in the identification and development of antiviral agents for use in anticipation of a large smallpox outbreak.
In light of these recent events, Dr. Craig Vanderwagen, a Senior Partner at Martin, Blanck, and Associates and Director at East West Protection, stated the “Use of smallpox virus as a weapon is a low probability event, however its use would have potentially devastating consequences in deaths and in social and economic impact.”
Smallpox, a Biological Weapon
Smallpox (variola virus) is unique in that it is only a human pathogen. It has no animal reservoirs and persists outside the human body for only a short period. Smallpox is a highly contagious viral disease, with about half of those exposed developing infection. Smallpox has a fatality rate of 30 percent or higher among unvaccinated individuals and in the absence of any specific therapy.
Smallpox, a category A (high priority) biological weapon, presents a serious threat to civilian populations due to its easy transmissibility, high morbidity and mortality. Smallpox is attractive as a bioterrorism agent because it has a long incubation period that allows infected individuals to travel before showing illness, it can be spread as an aerosol, and it has a high degree of contagiousness person-to-person. An aerosol release of smallpox would disseminate widely, given the considerable stability of smallpox in aerosol form and the likelihood that the infectious dose needed is very small. Additionally, advanced molecular techniques have created a possibility for the artificial creation of smallpox.
If an outbreak of smallpox were to occur, multiple factors could contribute to a more rapid spread of smallpox than previously: (1) virtually non-existent smallpox immunity in the absence of the naturally occurring disease and the discontinuation of routine vaccination; (2) possible delayed recognition of smallpox by health care personnel; (3) increased population mobility and crowding; (4) potential use of a more virulent, weaponized virus with decreased incubation periods.
Smallpox Preparedness and Response
In 1966, the WHO launched a global vaccination campaign against smallpox. The last naturally occurring case in the world was in Somalia in 1977, and smallpox was officially declared eradicated in 1980. To this day it is the only human disease to be eradicated. In 1971, after it was largely eliminated from the world, health care professionals halted routine vaccination among the general public because it was no longer necessary for prevention. Because of this, much of the population has no pre-existing immunity.
For use in the event of an outbreak, the Strategic National Stockpile (SNS) maintains sufficient doses of the smallpox vaccine ACAM2000 to vaccinate the entire U.S. population. In addition, in November 2013, Bavarian Nordic completed a delivery of 20 million doses of IMVAMUNE smallpox vaccine to the SNS. Because of the severe side effect profile of ACAM2000 for at-risk individuals, IMVAMUNE is being stockpiled for emergency use in individuals with compromised immune systems or with atopic dermatitis, including pregnant women and children with these conditions. September is National Preparedness Month, and Dr. Vanderwagen stated, “Preparedness and response planning must meet the needs of the whole population, including our most vulnerable people.” Antivirals also might be needed to treat individuals with active smallpox infection. One such product, Arestyvyr, has been contracted for two million doses for the SNS, where it is in the process of being stockpiled. Federal guidance on using the medical countermeasures contained in the SNS will be necessary to inform state and local planners. At NACCHO’s Preparedness Summit in April 2014, a federal panel announced the impending release of clinical utilization guidance for smallpox vaccines; such guidance has not yet been published as of press time.
Public health and health care professionals should be well equipped with all information necessary for appropriate and effective smallpox management in the face of such an outbreak. State and local planners should have a post-event smallpox plan already in place. Essential components of the public health response to a smallpox outbreak include: identifying, isolating, and treating cases; identifying, tracing, and monitoring contacts; vaccination (ring vaccination and mass vaccination); adverse event monitoring; quarantine considerations; and communications. Local health departments should continue to explore effective ways to educate the public and disseminate information regarding smallpox preparedness. Dr. Yehuda Danon, an Israeli physician and a panelist at a session on smallpox preparedness at the 2014 Preparedness Summit, said, “Our national exercise in Israel demonstrated that quarantine alone is not likely to be effective. So many elements need to be planned for—first responder protection, medical countermeasures, clinical guidelines, biosurveillance—they are all important.”
Have these recent events prompted your health department to re-examine smallpox preparedness planning and response efforts? What sorts of additional resources, tools, or training would assist your smallpox preparedness efforts? How are you incorporating vulnerable populations in your preparedness planning? Let us know in the comments section!
- Hanson JC. 2012. Smallpox: New Perspectives Regarding risk Assessment and Management. J Bioterr Biodef. S4:002. doi:10.4172/2157-2526.S4-002. http://omicsonline.org/2157-2526/2157-2526-S4-002.php?aid=8948
- Sato H. 2011. Countermeasures and Vaccination Against Terrorism using Smallpox: Pre-event and Post-Event Smallpox Vaccination and its Contraindications. Environ Health Prev Med. 16(5). http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3156838/
- FDA. 2013. ACAM2000 (Smallpox Vaccine) Questions and Answers. http://www.fda.gov/BiologicsBloodVaccines/Vaccines/QuestionsaboutVaccines/ucm078041.htm
- Bavarian Nordic. 2013. Bavarian Nordic Complete Delivery of 20 Million Doses of IMVAMUNE Smallpox Vaccine to the US Strategic National Stockpile. Press Release. http://www.bavarian-nordic.com/investor/news.aspx?news=3051
- Buonsenso D, Gargiullo L, Cataldi L, Ranno O, and Valentini P. 2011. Smallpox and Bioterrorism: History and Evaluation of Current State and Medical Knowledge. J Clinic Res Bioeth. S3:001. doi:10.4172/2155-9627.S3-001. http://omicsonline.org/2155-9627/2155-9627-S3-001.php?%2520aid=2575