Issue 15 / 5 May 2014

WHEN Australian virologist Frank Fenner stood in front of the World Health Assembly to declare the world free of smallpox back in 1980, it marked the first time public health efforts had succeeded in eradicating a major infectious disease.

In fact, it’s still the only example of such global eradication, though the campaign to wipe out polio has come tantalisingly close in recent years.

With smallpox defeated, health authorities agreed remaining stocks of live variola virus would be destroyed once approved research had been completed.

This month, the World Health Assembly (WHA) will once again be considering whether that time has come, after deferring a decision when the subject was last considered 3 years ago.

Since eradication, the live virus has been kept in two secure laboratories, one in Russia and one in the US. Both countries opposed destruction of the virus in 2011.

With the disease banished, it might seem logical to think keeping stocks of the virus poses an unnecessary risk — what if it were to escape, or if terrorists were to take over the secure facilities?

But, as usual, it’s not that simple.

A group of infectious disease specialists, led by Dr Inger Damon from the US Centers for Disease Control and Prevention, argue in PLOS Pathogens the research agenda on the variola virus is far from complete.

Since 1980, all research on the live virus has required WHO approval and these authors argue the scope of that research has become overly narrow, restricted essentially to finalising work on diagnostic, preventive and treatment products to be used in the event of a reemergence of the disease.

“Fundamental research has been greatly limited over the past decade”, they write. “Thus, basic variola virus research projects that could potentially lead to other advances in public health efforts have become increasingly absent from the list of WHO-approved projects.”

Given the rapid advances in genomics and molecular technologies in recent decades, further research might deliver benefits undreamed of by the pioneers of smallpox eradication in the 1960s and ’70s.

But those technological advances may also pose risks.

One of the arguments the US and Russia made for keeping the virus in 2011 was that it might be needed to manufacture a vaccine in the event of a bioterrorist attack.

Developments in synthetic biology, combined with the easy availability of multiple variola virus genome sequences in the published literature, mean the deliberate reintroduction of the virus is a risk, as the PLOS Pathogens authors point out.

“While the likelihood of the emergence of, or creation of, either drug- or vaccine-resistant versions of smallpox is unknown, continued investigation to identify additional countermeasures, for example, through screening using functional genomics or proteomics approaches, can further enhance our state of preparedness”, they write.

The final destruction of the remaining stocks of the virus would be a powerful tribute to all those who worked to eradicate the disease, not least Dr Fenner, who chaired the global commission charged with confirming its eradication.

But the PLOS Pathogens authors believe we need a much bigger conversation about the virus’s research potential before that should be allowed to happen.

It will be interesting to see what the WHA decides to do this time.

 

Jane McCredie is a Sydney-based science and medicine writer.

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