Smallpox was declared eradicated in 1980, with known seed stock retained in two high security Biosafety Level 4 laboratories in the United States and Russia. Experts agree the likelihood of theft from these laboratories is low, and that synthetic creation of smallpox is a theoretical possibility. Until 2017 it was believed that synthetic smallpox was technically too complex a task to be a serious threat. However, in 2017, Canadian scientists synthesised a closely related orthopoxvirus, horsepox, using mail order DNA and $100,000. Simultaneously, terrorist groups have declared intent to conduct biological attacks. In this context an exercise was held on August 16th 2018, with international and cross-sectoral stakeholders to review preparedness for a bioterrorism attack in the Asia-Pacific region and globally. The exercise was conducted by The National Health and Medical Research Council (NHMRC) Centre for Research Excellence, Integrated Systems for Epidemic Response, with contextual input from the Ministry of Health and Medical Services Fiji. The scenario involved a deliberate release in Fiji, followed by a larger release in a more populous Asian country. Mathematical modelling was used to underpin epidemic projections under different conditions. The exercise alternated between clinical, public health, emergency and societal responses, with participants making real-time decisions on cross-sectoral response across the region and the world. Key weak points which are influential in determining the final size and impact of the epidemic were identified (based on mathematical modelling of transmission in Fiji and globally). We identified potential gaps in preparedness for smallpox and factors which influence the severity of a smallpox epidemic. This included identifying which determinants of epidemic size are potentially within our control, and which are not. Influential factors within our control include: preventing an attack through intelligence, law enforcement and legislation; speed of diagnosis; speed and completeness of case finding and case isolation; speed and security of vaccination response, including stockpiling; speed and completeness of contact tracing; protecting critical infrastructure and business continuity; non-pharmaceutical interventions (social distancing, PPE, border control); protecting first responders; operational support and logistics; social mobilisation and risk communication. Based on discussion at the workshop between diverse stakeholders, recommendations were made to guide improved prevention, mitigation and rapid response, thus providing a holistic, cross-sectoral framework for prevention of a worst-case scenario smallpox pandemic.

Bioterrorism and pandemics pose great risk to the health and safety of our modern world. Pandemic scenario exercises commonly use diseases that are most likely to cause moderate harm in an epidemic scenario such as influenza. Despite the generalisable nature of most pandemic responses, exercises often fail to take account of the broader impacts of a pandemic scenario. In August 2018, The Exercise Mataika pandemic workshop was conducted by the NHMRC Centre for Research Excellence Integrated Systems for Epidemic Response at the University of New South Wales, Australia. By utilising a high risk, worst case scenario – the deliberate release of Smallpox in Fiji and a much larger Asian country – impacts not often considered in pandemic planning, such as the resiliency of the health system, absenteeism, social cohesion, and broader impacts on society were considered, and compared, across geographic and social groupings. This study aimed to collect and analyse participant perceptions and evaluation of Exercise Mataika. A mixed methods study collecting participants ratings of experience, value and utility aspects of the scenario coupled with a thematic analysis of qualitative responses was conducted. Quantitative ratings for the activity were overwhelmingly positive, with respondents highlighting that the activity was useful, different in format, identified issues not often explored in pandemic exercises, and was a valuable educational and networking opportunity. Qualitative analysis and combined mixed-methods analysis revealed more nuanced findings. While respondents remained positive about the exercise format, subgroups highlighted potential missed opportunities and areas within the scenario where greater focus could have been directed. Overall the findings highlighted the value of including a wide range of exercise attendees both across sectors and nationalities, and addressing a far broader set of considerations across multiple domains. These findings will guide future development of pandemic response exercises and education.

On August 16th, 2018, we held Exercise Mataika to test preparedness for a worst-case scenario of a smallpox attack which begins in the Pacific and is followed by a larger scale attack in a highly populous Asian country. The exercise was underpinned by mathematical modelling which aimed to determine the duration and magnitude of the epidemic under different scenarios, the critical threshold for epidemic control, and scenarios where the current stockpile of vaccine is adequate. We constructed a modified SEIR model for smallpox transmission. We found that time to commencing the response, rates of contact tracing and ring vaccination, and rates of case isolation are all influential factors on epidemic size and duration. Ideally, the response should commence in 20 days after the attack, corresponding to 8 days after the first symptoms appear, given an average incubation period of 12 days. Every day of delay worsens the epidemic. The WHO stockpile of vaccine of 34 million doses is adequate if rates of case isolation and ring vaccination are maintained above 60%. If rates of contact tracing, ring vaccination and case isolation fall below 53%, epidemic control is lost. In such a scenario, the epidemic persists for longer than 10 years and over a billion doses of vaccine are needed for epidemic control. There are modifiable factors which can prevent a catastrophic scenario following smallpox re-emergence. These include very rapid response time and high rates of isolation and ring vaccination. Training and capacity building, as well as pre-vaccinated teams, can also assist with rapid response. In low income countries, a smallpox epidemic could overwhelm the health system and far exceed human resource capacity, so low rates of case isolation and contact tracing is a realistic possibility. The consequences of poor epidemic control are catastrophic if rates of case isolation and ring vaccination fall below 53%, the threshold for epidemic control. Global cooperation is also critical, to ensure that vaccine and other resources are directed quickly to affected areas.