Understanding North Korea's Biological Weapons Potential

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There have been several stories recently published regarding the biological weapons capabilities possessed by the totalitarian regime of North Korea. Thus far, most of the media attention has been to situate this development, for good reason, in a general national security and defense context. However, biological weapons are a difference in kind when it comes to the tools of warfare and merit special attention because of their unique characteristics. Some of these characteristics include potential for contagiousness, induction of societal panic, and the need for special public health and medical preparedness.

To those in the field, it is no surprise that North Korea possesses biological weapons. Though they are a signatory of the Biological Weapons Convention (BWC), it matters little as the former Soviet Union operated an extensive biowarfare program despite being a party to the convention -- and they have demonstrated their prowess with deploying chemical agents such as VX in order to kill. 

The latest news surrounds the fact that a North Korean defector has antibodies to anthrax in his bloodstream. These antibodies are likely the result of prior vaccination which is somewhat routine for many militaries, including our own. It has also been reported that South Korea has purchased a small stockpile of anthrax vaccine (though this purchase seems to be linked to fears over the 2015 accidental shipment of live anthrax spores to Osan Air Base). 

Concern is focused on a "pesticide" factory (Pyongyang Bio-technical Institute) that may be a clandestine dual-use facility capable of producing large amounts of biological weapons that are rumored to be capable of being mounted on missiles (in the case of anthrax). Smallpox -- a disease vanquished from the planet to which many are susceptible due to suspension of the vaccination program -- has also been mentioned as a potential possession of North Korea. 

In the coming weeks, it will be important for those in the reach of North Korea to fortify and prepare hospitals and healthcare providers to recognize, diagnose, and treat conditions such as anthrax and smallpox. Such infectious disease emergency preparations were recently tested with South Korea's experience with MERS and hopefully improvements that will impact biodefense capacities were made. The US has made major gains in preparedness since the 2001 anthrax attacks but any biological attack -- particularly in today's political and societal context -- would be severely disruptive and stress the nations hospitals (especially given the current influenza season) as well as the biomedical enterprise that will be tasked with development vaccines and treatments.

It can be assumed that South Korean and American troops in the region are vaccinated against anthrax and smallpox.  Effective vaccines, both stockpiled in large numbers in the US, exist for both these agents and anthrax can be treated with several different antibiotics as well as with antibody-based treatments. 

A biological attack would unleash global pandemonium and the natural human response will be to panic, flee, and possibly shun the victims in fear of contagion (despite the fact that anthrax -- the most likely candidate weapon -- is not contagious). This is, in many ways, the opposite response to many other disasters. The use of smallpox would cross a line that, to many, is more serious than the use of a nuclear weapon and I suspect (and hope) would be met with a fierce response.

Biological weapons are not a fanciful threat and preparing for them is an important component of national security -- a core function of government. Whether or not North Korea possesses or will use such weapons, it is nevertheless important that the general public, politicians, and healthcare providers are apprised of the very real and dangerous threat they pose. 

Untangling the Fate of the Dengue Vaccine

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It can't be emphasized enough the dengue fever is a deadly viral infection that exacts a considerable burden on the world. Any tool to diminish this impact would be welcomed by the world. This mosquito-borne virus has a unique aspect about its pathophysiology that makes it especially intriguing and difficult to develop a vaccine against. There are 4 types or strains of dengue virus (maybe five) that circulate and it has been shown that antibody-based immunity to one strain enhances the severity of subsequent infections with the other strains. This phenomenon is known as antibody-dependent enhancement and is what accounts for severe dengue. 

Because of this capacity of dengue, it is essential that any vaccine not induce antibodies that lead to enhancement of infection. The only dengue vaccine on the market to seemingly clear this hurdle was Sanofi Pasteur's Dengvaxia which has been licensed in several countries (but not the US). This vaccine, based on a yellow fever vaccine platform, is protective against 4 strains of dengue.

Dengvaxia has been in the news because of new longer term data showing that in those with no prior immunity to dengue, the vaccine increases the chances that infection will lead to severe disease. Perhaps vaccine induced antibodies -- in the absence of any naturally formed antibodies -- are enhancing. Interestingly, in the clinical trials of this vaccine an increased rate of hospitalization and severe dengue was noted in children less than 9 years of age which restricted its use to those above 9.  I wonder if this is because those younger than 9 are more likely to have escaped natural dengue infection and be liable to develop severe dengue due to vaccine-induced antibodies. Of course, some people may reach 9 years of age and escape natural infection and have a similar risk as those below age 9.

It may be that restriction of the vaccine to those with laboratory confirmed dengue -- irrespective of age -- will be the best way to salvage this vaccine as a tool to prevent severe dengue. However, adding a lab test will considerably increase the costs and logistical difficulty of deployment. This finding also makes it very difficult to market the vaccine to travelers, most of whom will not have any natural dengue antibodies.

While this negative finding is clearly a setback for Sanofi, the dengue vaccine field, and for the countries using the vaccine it should be seen as a validation for the rigor of post-licensure vaccine safety testing in which this signal was uncovered and openly publicized. This finding should not be misinterpreted as some way to bolster the veracity of the anti-vaccine movement (which I am sure is inevitable) and be used to smear other vaccines to which this finding is wholly inapplicable.