ABOVE: Eva Harris (far right) oversees the collection of blood samples from a participant of the Nicaraguan cohort study in 2005. COURTESY OF ALEJANDRO BELLI

When Eva Harris arrived in Nicaragua for the first time in March 1988, the poverty-stricken country was in the middle of the decade-long Contra War between its socialist government and US-backed right-wing rebel groups. Harris had traveled to Central America through a volunteer organization and was financing her own trip with money saved from working odd jobs during a gap year she took after graduating from Harvard University the previous spring. Coinciding with her arrival in Managua, the Nicaraguan government was devaluing the country’s currency—and the funds that were supposed to cover Harris’s months-long trip were suddenly stretched thin. “It was really a petrifying moment in my life,” she says.   

After wandering the streets of the country’s capital city searching for a place...


Through the volunteer organization, Harris was stationed at a manufacturing plant that was producing blood plasma to provide transfusions for Nicaraguan soldiers fighting on the front lines. The factory was having a problem with bacterial endotoxins in the plasma, and the kits that workers there used to detect the toxins were defective. Harris was tasked with finding a way to make the test kits work. One of the problems, she realized, was the quality of water used to carry out the test. Using ampules of sterile water, alcohol, cotton swabs, and tongs, Harris put together a makeshift apparatus that solved the problem. 

Her accommodations also improved when Irene Vallecillo, the chemical engineer who directed the plasma factory, invited Harris to stay with her instead. Harris ended up frequenting Vallecillo’s home for more than two decades as she continued to take regular trips to Nicaragua. “She’s become like my family,” Harris says. 

Since that first visit to Central America, Harris has returned multiple times a year to build scientific infrastructure and to conduct crucial studies on arthropod-borne pathogens such as mosquito-transmitted dengue, which is endemic to several Latin American countries. “She’s made a huge contribution to understanding the development of immunity to dengue,” says Aubree Gordon, an epidemiologist at the University of Michigan and one of Harris’s former students and longtime collaborators. Harris has “really helped with the buildup of laboratory capacity in Nicaragua and in other countries. I think that’s just amazing work.” 

Notable positions & awards

  • Professor, Division of Infectious Diseases, School of Public Health, UC Berkeley (2008–present)
  • Director, Center for Global Public Health, School of Public Health, UC Berkeley (2007–present)
  • President, Sustainable Sciences Institute, San Francisco, California (1998–present)
  • Global Citizen Award, United Nations Association, East Bay Chapter, 2012 
  • Pew Scholar, Pew Scholars Program in the Biomedical Sciences (2001–2005)
  • MacArthur Fellowship, MacArthur Foundation (1997–2002)

Visions of a better world

Harris was born in New York City in 1965 to a pair of academics. Her mother, Naomi Sager, was a computational linguist at New York University. Her father, Zellig Harris, was an influential mathematician and linguist at the University of Pennsylvania whose ideas shaped those of his most famous trainee, the linguist Noam Chomsky.

Although she spent most of her childhood and adolescent years in New York City, Harris spent summers in France with her parents. “I really grew up very French,” she says. “I practically spoke French before English.” In Paris, Harris’s parents were part of a social circle that would meet over meals to talk about politics and the state of the world. The group was diverse, Harris recalls, and included people in both white- and blue-collar jobs. “That was a very big part of my life—those people and the views of the society that I listened to, which were socialist and very much about a better future,” Harris says. “Hearing those animated discussions imbued me with a vision of the world that could be better than what’s out there now.”

Greatest Hits

  • Found that the dengue virus protein NS1 plays a key role in making blood vessels more permeable in patients with severe dengue fever.
  • Demonstrated that people who had been infected with one type of dengue were more likely to have severe reactions to an infection with another type, depending on their antibody levels, a phenomenon known as antibody-dependent enhancement.
  • Tracked the epidemiology of dengue outbreaks in Nicaragua through long-term assessments at hospitals and health centers and in the community.

Once she became a teenager, Harris started to travel across Europe on her own. While enjoying the rich history and beauty that the continent had to offer, she developed a desire to give back. “I always felt that society was very lopsided. That there was this huge gap between the haves and the have-nots,” Harris says. “[My family] wasn’t rich, but we had a place in New York, I could travel, and I wasn’t going hungry. I wanted everyone to have the same opportunities.”

That desire for equity motivated Harris to become politically active. Starting in high school, she joined protests in Washington, D.C., calling for nuclear disarmament and the end of US military activities in foreign countries such as Nicaragua, she says. “I was very upset about US intervention in Central America.”

At the same time, Harris was drawn to science. In one of her high school biology classes, Harris caught her first glimpse of the cell and was blown away by the complex world held within the tiny unit. “I saw the cell in the body as the most beautiful metaphor for human society, because in a cell, all the elements work together for the good of the greater whole,” Harris says. “That was very inspiring to me. I had this vision of, well let’s just learn from ourselves, how to get along.”

In 1983, Harris went off to Harvard University to study biochemical sciences. She spent the summers in labs in the US and Europe dabbling in a range of projects, from dissecting leeches for neurophysiology studies to examining mitochondria in yeast.

Bringing science to Latin America

After completing her undergraduate studies at Harvard, Harris was accepted to several PhD programs. But instead of immediately enrolling in graduate school, she decided to take a year off to work and travel. Nicaragua was her final stop, and of all the places she’d gone, it was the country she knew she’d return to. After she began her doctorate in the lab of Jeremy Thorner, a cell and molecular biologist at the University of California (UC), Berkeley, in the fall of 1988, Harris returned to Nicaragua every summer to bring laboratory equipment and to teach workshops on molecular biology techniques such as the polymerase chain reaction (PCR) to scientists and clinicians there. 

I saw the cell in the body as the most beautiful metaphor for human society, because in a cell, all the elements work together for the good of the greater whole.

—Eva Harris, University of California, Berkeley

Before leaving on those trips, Harris would scour the halls of UC Berkeley’s science buildings for discarded equipment such as gel boxes, vortex mixers, pipette tips, and glassware. Along with a group of like-minded friends, she cleaned and repaired the items before taking them to Nicaragua. “People thought I was a little too lenient, letting her take off so many chunks of time throughout her graduate career,” Thorner says. “But she was so passionate about it. And she was so efficient during the time she was in the lab that I was happy to support her.” 

Once her doctoral dissertation was complete in 1993, Harris accepted a postdoctoral fellowship at Stanford University. Instead of going straight back to the lab, however, Harris took a year off from research to focus on her effort on scientific capacity–building projects. One year turned out not to be enough. Harris ended up transferring her postdoc to UC San Francisco (UCSF), where her advisor, Nina Agabian, a professor of global health science, allowed her to continue her work in Latin America.

In addition to working in Nicaragua, Harris and other volunteers helped introduce molecular science expertise, technology, and resources to Ecuador, Bolivia, Cuba, and other countries. With Josefina Coloma, a researcher now at UC Berkeley’s School of Public Health, Harris led the Applied Molecular Biology/Appropriate Technology Transfer Program at UCSF. The initiative aimed to provide researchers in developing countries with resources to help them set up their own epidemiological and biomedical studies to combat infectious diseases. 

In one workshop, for example, Harris performed manual cycling—a cheap alternative to laboratory PCR—on samples of the disease-causing parasite Leishmania. When the bands of Leishmania DNA showed up on the gel, people were “elbowing their way to take a look,” Harris recalls. None of the attendees had ever worked with DNA before, so this method “just blew everyone’s mind,” Harris says, adding that many of the people who attended those courses are now the heads of science and health programs in several Latin American countries.  

Harris’s work earned her a MacArthur Foundation Fellowship in 1997, when she was an assistant adjunct professor at UCSF—a position she had been offered after completing her postdoc. The award provided funding to establish the Sustainable Sciences Institute (SSI), an organization designed to build research and public health resources in developing countries. As the years passed, however, Harris realized that she missed the lab. While racking her brain for ways to bridge her love of basic science with her passion for putting research into a social context, she realized that studying an infectious disease would be the best way forward. Not only were pathogens fascinating biologically, they would also provide the opportunity to deal with a much “broader picture,” Harris says, “because infectious diseases were deeply connected to various aspects of society, including socioeconomic status and politics.”

To find the perfect pathogen to study, Harris went around to contacts in the health departments of various Latin American countries to ask which infectious disease was their top concern. One of the answers that came up time and time again was dengue fever.

Dancing and dengue

Harris started setting up her own lab to establish a research program on dengue in the late 1990s while she worked on her postdoc at UCSF. “We would meet in coffee shops in San Francisco, because the lab space was not ready,” recalls Michael Diamond, one of Harris’s first postdocs, who is now a virologist and immunologist at the Washington University School of Medicine in St. Louis. “She was clearly excited by the science and had a lot of interesting ideas.” 

After her lab was ready, Harris and her team got to work deciphering the molecular biology of the dengue virus, examining the structure and function of the pathogen and the features that contributed to its pathogenicity. Through years of meticulous work, her group demonstrated the critical role the viral protein NS1 plays in causing permeability in the lining of the blood vessels, a key feature of the severe form of dengue fever. They are now working on further elucidating the mechanism of NS1-induced vascular leak.

She and her team also established a long-term study of children in Nicaragua, regularly collecting blood samples to monitor for dengue infections among families living in more than 4,000 households. The researchers aimed to better understand the spectrum of the disease, how it is transmitted, and the immune responses that patients mount. The results gave the researchers much-needed details about antibody-dependent enhancement (ADE), a phenomenon in which antibodies to a virus can lead to worse illness during a secondary infection. Dengue comes in four different types that carry unique surface molecules. Through their cohort study, Harris and her colleagues demonstrated that those who were infected with one type were more likely to have severe—and sometimes deadly—disease when infected with another. They have also found that ADE occurs in previously infected individuals who possess a specific range of antibody concentrations, a finding that has major implications for the development of vaccines.

Harris has really helped with the buildup of laboratory capacity in Nicaragua and in other countries. I think that’s just amazing work.

—Aubree Gordon, University of Michigan

The cohort study, which is still ongoing, has also helped reveal important insights into the human immune system’s response to the Zika virus, which hit the Americas in 2015, and has challenged long-standing scientific hypotheses about antibody dynamics in response to dengue infection. “Everyone has thought that antibodies [to dengue] wane and then you get to a danger point,” where infection with another serotype can make you develop severe illness, she explains. “When we looked at 15 years of data, we found that antibodies are very stable after a first infection.” A key factor that determines whether someone will get sick after the second infection appears to be the level of antibodies developed after the first infection. 

Building on the results of the cohort study, Harris has spearheaded several ongoing projects. One is examining the unique features of an individual’s immune system that lead to different levels of innate immunity, and how that varies with factors such as environment, pathogen exposure, and age. Another project involves looking more closely at the adaptive immune response to dengue to help inform vaccine development. Through the years, Harris’s research has spanned virology, immunology, diagnostics, and epidemiology. 

Much of this work has been conducted in Latin America, where she also has ongoing scientific capacity–building efforts. Her work in those countries is currently stalled, however, as a result of the COVID-19 pandemic. Earlier this year, she was sheltering at home in San Francisco with her husband, a professor of US history and foreign policy at the City College of San Francisco, and her 19-year-old son, who is currently back at home from college. Because of the pandemic, Harris has temporarily pivoted her research, launching studies into the pathogenesis of COVID-19 and a longitudinal assessment of asymptomatic and past infections in 5,000 residents in the East Bay.  

Balancing many projects has some downsides. When things get really busy, “I’ll go to two to three hours of sleep a night, and I’ll burn out horribly,” Harris says. Even so, Harris somehow finds time for her favorite pastime: dance. Her love of music and movement is clear even over Zoom. While talking via the video conferencing service in May, she spontaneously busted out dance moves while describing her love for a wide range of musical genres, including hip-hop, salsa, and merengue. Dancing is what usually keeps her going through tough times—but the pandemic has made it difficult to enjoy that passion. “It’s hard not to be able to do that now,” Harris says. However, she adds, the upside is that she gets to spend more time with her son. 

“She’s the ‘dancing scientist,’” says Coloma, now the executive director of SSI. “That’s how she gets her energy.”

Interested in reading more?

Magaizne Cover

Become a Member of

Receive full access to digital editions of The Scientist, as well as TS Digest, feature stories, more than 35 years of archives, and much more!
Already a member?