COVID-19 has provided a vivid reminder of the power of biological threats. But the threat doesn't come from natural sources alone. Weaponized contagious diseases — which were abandoned by the United States, but developed in large numbers by the Soviet Union, right up until its collapse — have the potential to spread globally and kill just as many as an all-out nuclear war.

For five years today’s guest — Andy Weber — was the US Assistant Secretary of Defense responsible for biological and other weapons of mass destruction. While people primarily associate the Pentagon with waging wars, including most within the Pentagon itself, Andy is quick to point out that you can't have national security if your population remains at grave risk from natural and lab-created diseases.

Andy's current mission is to spread the word that while bioweapons are terrifying, scientific advances also leave them on the verge of becoming an outdated technology.

He thinks there is an overwhelming case to increase our investment in two new technologies that could dramatically reduce the risk of bioweapons and end natural pandemics in the process.

First, advances in genetic sequencing technology allow direct, real-time analysis of DNA or RNA fragments collected from the environment. You sample widely, and if you start seeing DNA sequences that you don't recognise — that sets off an alarm.

Andy says that while desktop sequencers may be expensive enough that they're only in hospitals today, they're rapidly getting smaller, cheaper, and easier to use. In fact DNA sequencing has recently experienced the most dramatic cost decrease of any technology, declining by a factor of 10,000 since 2007. It's only a matter of time before they're cheap enough to put in every home.

The second major breakthrough comes from mRNA vaccines, which are today being used to end the COVID pandemic. The wonder of mRNA vaccines is that they can instruct our cells to make any random protein we choose — and trigger a protective immune response from the body.

By using the sequencing technology above, we can quickly get the genetic code that matches the surface proteins of any new pathogen, and switch that code into the mRNA vaccines we're already making. Making a new vaccine would become less like manufacturing a new iPhone and more like printing a new book — you use the same printing press and just change the words.

So long as we kept enough capacity to manufacture and deliver mRNA vaccines on hand, a whole country could in principle be vaccinated against a new disease in months.

In tandem these technologies could make advanced bioweapons a threat of the past. And in the process contagious disease could be brought under control like never before.

Andy has always been pretty open and honest, but his retirement last year has allowed him to stop worrying about being seen to speak for the Department of Defense, or for the president of the United States – and we were able to get his forthright views on a bunch of interesting other topics, such as:

• The chances that COVID-19 escaped from a research facility

• Whether a US president can really truly launch nuclear weapons unilaterally

• What he thinks should be the top priorities for the Biden administration

• The time he and colleagues found 600kg of unsecured, highly enriched uranium sitting around in a barely secured facility in Kazakhstan, and eventually transported it to the United States

• And much more.

Job opportunity: Executive Assistant to Will MacAskill

Audio mastering: Ben Cordell.

Transcriptions: Sofia Davis-Fogel.