Clinical trials for potential vaccines and antidotes can take decades to develop and so tracking their development can be a long process. If they are approved by the public health authorities, such as the US Food and Drug Administration (FDA), access to them is often limited to emergency situations and military or governmental personnel, making their availability to the general public either very costly or impossible. However, some developments in biological, chemical and radiological agent mitigation may be close to becoming more mainstream.

With these advances comes increasing opportunities to better protect against the effects CBRN agents can have when deployed  maliciously against the public. Here we take a look at some of the most interesting developments in the field and consider their impact on the threat of CBRN attacks in the future.

BIOLOGICAL AGENT DEFENCE

Although there is no “one size fits all” treatment against agents deployed in biological warfare, the recent developments in Ebola and Malaria vaccination mitigate the risks associated with two major potential biological weapons. 

Over 100,000 people have been vaccinated against the Ebola virus in the Democratic Republic of the Congo (DRC) since the outbreak began in August 2018. Although the rVSV-ZEBOV vaccine has, so far, been proven to be both safe and effective, it is not commercially licenced, which is why its use is currently restricted to the DRC in an emergency capacity. Whilst the vaccine is thought to provide
immunisation for up to twelve months, it is only effective against the Zaire strain of the Ebola virus. Attempts to weaponise Ebola would likely focus on strains for which a vaccination has yet to be found, but the success of rVSV-ZEBOV lays the foundations for further investment in this area.

Whilst there is no commercially available Malaria vaccine, children in Sub-Saharan Africa have been undergoing a clinical trial for the RTS,S vaccine since 2009. In April 2019 the positive results from the trial led to a vaccination pilot scheme for children in Malawi, Ghana and Kenya. Malaria prevention is thought to occur in 4 out of 10 cases, but 4 doses are needed for each child. However, up to 20 further vaccines are currently in advanced development stages, which have the potential to lead to increased immunity in the future.

With the creation of these vaccines, there are opportunities to improve mitigation against the effects of a biological attack. The existence of effective medical countermeasures may also have the additional advantage of discouraging potential attackers in the first instance due to the increased risk of failure. However, a lack of availability, public distrust in medical professionals and current concern over vaccination side effects are all hurdles that would have to be overcome by authorities during an outbreak.

CHEMICAL AGENT DEFENCE

Whilst there are no plans to replace physical protection from chemical agents, such as respirators and chemical suits, promising advances are being made in post-exposure treatment. At present, the effective treatment of chemical attacks relies principally on decontamination and symptom treatment, but a number of novel therapies are currently under development. Nerve agents, such as Sarin and VX gas, are among the most toxic substances known to man. Even brief exposure to these agents can cause death within minutes. Once a nerve agent enters the body it begins shutting down enzymes which control the nervous system. This means any potential antidote to nerve agent exposure has to work fast. Medics in Syria have used pralidoxime and atropine in the wake of chemical attacks, but these antidotes are not effective against all nerve agents and have proved unreliable in general.

Now, scientists have identified naturally occurring enzymes which can be modified in order to break down nerve agents. In a proof of concept study conducted by scientists in Germany and Israel, these enzymes have been proven to work in guinea pigs exposed to lethal doses of VX gas. This novel treatment is still in the developmental phases and has not been tested on humans. However, if
successfully developed for human treatment it could greatly increase our defence against the effects of chemical weapons and, therefore, decrease the likelihood they’ll be used.

RADIOLOGICAL AGENT DEFENCE

With the increasing threat of nuclear development by Iran and North Korea, radiation countermeasure research has ramped up internationally. The potency of radiation poisoning is well-known, causing death, cancer and birth defects as well as long-term contamination of the affected sites.

Ex-Rad is an experimental drug which reportedly works by protecting cells exposed to radiation from cell damage. It has been developed in a public-private partnership with the US Department of Defence and Onconova Therapeutics and is one of few pharmaceuticals that can be used for acute radiation treatment. Ex-Rad has successfully completed stage 1 clinical trials and findings so far indicate that the drug is safe and well tolerated by humans, having produced no evidence of systemic side effects. Acute radiation treatment is generally considered as having a poor prognosis, but rapid deployment of Ex-Rad, which can be taken orally or intravenously, following a radiological attack would significantly mitigate the long-term health effects on contaminated individuals. This postexposure deployment is a key benefit of Ex-Rad, having significant advantages over inoculation, in that it can be used when needed rather than pre-emptively at random.