Influenza as a Bioterror Weapon

The Potential For Influenza as a Bioterror Threat
Or: What is This Terrorism Thing Anyway?
December 17, 2007
Revised From May 4, 2005

We are familiar with influenza as a naturally occurring disease that has caused countless deaths worldwide. There have been several epidemics worldwide over the past century, including an avian form that has decimated bird populations. Older estimates of casualties from the 1918 form, sometimes called the “Spanish Flu,” is said to either have killed 40-50 million people (in older reports), or 50 to 100 million people, possibly more than the entire course of The Black Death.

It is left to speculation to imagine the toll of the detonation of an atomic bomb on an American city. Of course, it depends on the bomb, and the city. Certainly, bombs today have exponentially more capacity for destruction than those dropped on Hiroshima and Nagasaki. But, would even one of those have the capacity to kill 40 million people—at least?

Today, the genomic structure of the 1918 form of Influenza has been published online at the GenBank database. (Actually, it was published back in 2005).

Suppose the Spanish Flu was not only recreated, but weaponized. Would we be able to avoid a toll like the one in 1918, of 50 million deaths? We could stockpile the vaccine. But, due to influenza’s short time between exposure and the onset of the virus, stockpiled vaccines would not necessarily help those exposed.

Because it is a disease that is not only contained to a laboratory but also is naturally occurring, it holds an additional capacity for bioterrorism because any outbreak of a weaponized form may be misattributed to the more common form. On the one hand, this thought is terrifying. But, on the other hand, it means that we might be able to respond to each with a similar apparatus.

Longini et al. used the pandemic of 1918 and the 1957 Asian influenza pandemic as a basis to analyze the health care system’s potential to withstand large scale pandemics. They recognize that a vaccine may not be fully capable of helping in the case of a pandemic, so they recommend stockpiling anti-virals. If the vaccine should become available, they believe that vaccinating 80% of those aged 18 and below would be 93% effective in containing pandemic influenza.

The steps necessary to prevent a pandemic are not purely based in vaccinations. Should a pandemic begin to emerge, vaccinations and anti-virals would be vital in curbing the spread of the disease. However, in preventing a pandemic, since subjects become symptomatic only 1-4 days after exposure, early detection of the disease is much more necessary than it would be in similar diseases such as smallpox. Further, a paper by Madjid found that influenza can be aerosolized, and the aerosolized form is more virulent than other forms.

The possibility of influenza being distributed in an aerosolized form suggests that instead of focusing purely on vaccination, we also could have detection systems in place. With the strain’s genomic structure becoming publicly available, the capacity for it to be released in an aerosolized form increases drastically. Even though influenza is a virus that has confronted American society for over a hundred years, longitudinal studies have learned more about the repercussions of the disease in recent years. Further, the capacity for vaccines to remain functional requires constant analysis on how the disease develops. Many further studies need to be done to combat the disease not only as a disease with the possibility for causing an epidemic, but also as a potential bioterror threat.

Even though influenza has been evident in society for a lengthy period of time, it is still a developing and changing disease. As we learn more about it—with the impending release of its genomic structure, and its evolution over time and adaptation to vaccines, influenza is as much a threat now as ever. With the new capacity of it becoming a bioterror agent, investing in combating it is doubly necessary not only to combat the naturally occurring disease, but also to prevent its use as a biological weapon.

Who would do such a thing, as weaponize influenza and then release it? Diseases, unlike bombs, can mutate in the course of their destruction. Perhaps the reason that we have not seen a weaponized pathogen like Influenza released successfully has been due to its capacity for mutation and coming back to annihilate the makers. Yet, the “pros” of bioterrorism to a successful assailant suggest that a strain like this one might still be developed. Unlike nuclear warfare, weaponized pathogens hold the capacity to kill an entire population yet leave their natural resources in-tact. Stockpile the antivirus to the disease in your own country, and then release it somewhere else. When the first reports of the disease spread, close your borders to that country and any country with reports of infection. The 1918 form was released in the hopes that it would help scientists combat modern forms of influenza, and the avian flu. Let us hope, and work to ensure, that that is all it is ever used for.