TEDMED: In your 2018 TEDMED Talk, you impart the importance of trying to stop pandemics before they start. You posit one way to begin to do this is to find patterns and test out new solutions for “everyday killer viruses” that can jump from animals to people, like rabies, but are not necessarily pandemics. What led you to choose to study rabies over another virus?
Daniel Streicker: In short, I followed the data and it led to rabies. Just consider the numbers— whereas many viruses jump into people or domestic animals only every few years or every few decades, rabies is transmitted from wild animals into new species every single day, probably hundreds of times over and governments around the world routinely carry out diagnostics on these cases. That means we get a high-resolution glimpse into the host jumping process: which hosts are involved, where it happens and when. The other thing that struck me about rabies was that we already knew so much about its basic biology. The decades of work done before me meant that I didn’t need to waste much time working out the fundamentals and could jump straight into what for me were the most exciting questions about anticipating and blocking transmission between species.
TM: Your research took you to the Peruvian Amazon to study rabies in vampire bats. You mention mudslides, power outages and stomach bugs among the challenges you encountered. What was the most difficult part of working in the field?
DS: I never worried too much about the uncontrollable things like getting sick or natural disasters. It was the things I thought I could control, but couldn’t and the things that seemed straightforward, but weren’t, that pushed me to the limit. In the first two years of the project in Peru, I tried to pack much more in than was humanly possible. Every time a key person arrived late, or our transportation didn’t show up, or bats were mysteriously difficult to catch, the realization that the day was lost stressed me out to no end. My solution was to work harder on less and less sleep. Looking back, I’m surprised the field team didn’t mutiny. After about 6 months, I remember walking down a street in Lima feeling like a sleep-deprived zombie, and suddenly realizing that no matter how much planning and wishful thinking I did, things would almost always go wrong in ways that I couldn’t predict. The only solution was to give myself a few extra weeks on both ends of every trip and go with the flow. That seems blindingly obvious now, but it took a lot of pain and frustration for me to get there.
TM: What impact has your research had on the communities you worked in that were facing a high prevalence of rabies transmittal?
DS: My longer term vision of preventing human and animal rabies by vaccinating bats is still a ways off, but I believe the road to getting there does provide tangible benefits. We have already made some progress with models that forecast rabies risk so this can potentially enable anticipatory vaccination before outbreaks begin, which would save lives. Beyond that, the nature of the work means we get exceptional access to remote communities in the Andes and Amazon that are typically underserved with respect to health access and education. This provides constant opportunities to talk to communities about the research we are doing and what actions they can take now to protect themselves and their animals (for example, using bed nets to prevent human bites or vaccinating livestock). I’d also like to think seeing us capture, handle and collect samples from mysterious animals like bats inspires some natural curiosity in younger generations and might even let them see science as a career possibility.
TM: You shared that you and your team have used genomics to forecast outbreaks and are working on an edible self-spreading vaccine that can “get rid of viruses at their source before they have a chance to jump to people”. What other creative or innovative tactics have you and your team employed in your efforts?
DS: One of my favorite things about science is that you occasionally get the chance to chase unconventional ideas. One of those was a recent project where a few colleagues and I became convinced that it might be possible to use machine learning to mine the genome sequences of viruses to predict what host they came from. This was a major challenge since when new viruses emerge, it’s almost always from a non-human animal, but it can take years or even decades of experiments and surveillance to find the culprit and while all that research is happening, the disease is free to emerge again. Although there’s still a lot of work to do in this area, we ended up developing algorithms published in Science that when provided, just a single viral genome can instantaneously predict which kinds of animals the virus came from. That effectively narrows the short list of animals for researchers to consider and in some cases could even guide how outbreaks are managed in real time to limit onward transmission.
TM: What do you see for the future of virus control/eradication?
DS: I think right now is an incredibly exciting time for disease control. We have technologies at our fingertips that just a few years ago were almost unimaginable. Transmissible vaccines are the example I discussed in my Talk, but other approaches like engineering pathogen resistance into hosts or using natural enemies or symbionts to control human pathogens like malaria or dengue within the mosquito vectors that transmit them are also taking off and show great promise. More and more the scientific question is not whether these tools work in the lab (we know they do), but how to apply them in the real world. That creates an interesting interdisciplinary challenge that will need to involve collaborations among the laboratory scientists developing the technologies, the field biologists who understand the natural systems, the epidemiologists who can project the outcomes on disease transmission, and the social scientists who can evaluate the economic costs and acceptability to the public. That last challenge is crucial since interventions in natural systems, particularly those involving genetic engineering of hosts or vaccines, are bound to be controversial. My view is that it’s vital to recognize in these situations that inaction costs lives. Rational, evidence-based assessment of the risks and benefits of these technologies will be increasingly important so we can actually realize the potential that new technologies have to transform human and animal health.