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Armed with a battery-operated minicomputer, a handheld DNA sequencer, and portable DNA-extraction machine, researchers gathered in a cassava field in Tanzania last August to chase down a major plant pest. Their plan was unprecedented: sequence the whole genome of the plant material to detect all potential viruses-and do so in a single day on a farm. "We called it tree lab, we were sitting under a tree," says Laura Boykin, a computational biologist at the University of Western Australia. Because plant samples are typically sent overseas to test for viruses, there's a big distance between the farm and the laboratory-thousands of miles if you're in eastern Africa. But within a few hours, a group of researchers, part of the Cassava Virus Action Project, determined what viruses infected the cassava crops on the farm and, more importantly, alerted farmers they would need to plant new crops that are resistant to the viruses they found. The researchers call themselves an "action group" because they're "taking the level of knowledge we get as scientists, down to the farmer," says Peter Sseruwagi, a research scientist at Mikocheni Agricultural Research Institute (MARI) in Tanzania. "We're able to show the farmer in a single day, what their crops are infected with." This is a big deal, especially in Africa, where cassava, a sweet potato-like starch, is intricately tied to lives and livelihoods for many of the people on the continent. The two main cassava diseases, cassava brown streak virus and cassava mosaic disease (CMD), are estimated to cause a loss of $2 billion to $3 billion annually (1). CMD alone can cause loss of up to 40% of a crop (2). The work of the cassava action project, however, doesn't only have an impact on African farmers. It can then pave the way to better crop science around the world. A group of farmers looks over a field of cassava in Mbinga, Tanzania, in 2016; unearthed cassava root is pictured (Inset). Researchers in the Cassava Virus Action Group have been able to increase yield by using portable DNA sequencers and extractors that facilitate the early detection of diseased plants. Image credit: Laura Boykin (photographer).

Just over 20 years ago, a Lyme disease vaccine called LYMErix was approved for sale in the United States. Researchers designed the vaccine to prevent the transmission of the tick-borne pathogen Borellia burgdorferi, which spurs a bacterial infection that can cause fever, headaches, and joint pain if left untreated. LYMErix was on the market for just four years. Concerns over adverse reactions and a lukewarm reception from public health agencies led the vaccine's manufacturer, SmithKline Beecham, to shelve the product in 2002. Since then, the need for a vaccine has grown. An estimated 300,000 people are diagnosed with Lyme disease in the United States annually, and reported cases of the disease have tripled since the 1990s. In some counties in the northeast United States, disease incidence has increased more than 300% over a 20-year period. "The people who live along the northeast corridor among the Mississippi River valley have suffered greatly because there is no Lyme vaccine," says Gregory Poland, a vaccine researcher at the Mayo Clinic in Rochester, MN. Now, a new round of Lyme disease vaccines is in development. European biotech company Valneva is in phase 2 clinical trials for a vaccine against six strains of Borrelia, which causes the disease in Europe and the United States. And researchers are working to develop a vaccine against Lyme disease based on a vaccine for dogs that was released in 2016. The pressure is on this time around to make the "perfect vaccine," says immunologist Richard Marconi at the Virginia Commonwealth University in Richmond, one of the researchers working on the dog vaccine-inspired approach. The black-legged or deer tick (Ixodes scapularis) is responsible for transmitting Lyme disease in the northeast, mid-Atlantic, and north-central United States. Image credit: Shutterstock/Steven Ellingson.

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