Tulika Singh: “Borders are not going to stop diseases. Ultimately, we are part of the same planet.”

January 29, 2026

by Alexander Rony

Tulika Singh is a postdoctoral scientist in UC Berkeley’s Harris Research Program, which is run by Professor Eva Harris. Singh was motivated to help others by her family’s history rising out of poverty in India. She studies mosquito-transmitted viruses like Zika and dengue that disproportionately harm poor people in tropical regions.

Singh spoke with UC Berkeley writer Alexander Rony about the life-saving work done by her lab and the current threats that could undo decades of research.

Three people bend over to look into a pan of water

TULIKA SINGH (RIGHT) CONDUCTS COMMUNITY OUTREACH IN NICARAGUA

PHOTO: CLAUDIA SANCHEZ SAN MARTIN

What is your lab’s mission?

Tulika Singh: The Harris Research Program has a mix of expertise in immunology, virology, epidemiology, and clinical research. Our goal is to connect science to public health and build capacity with a focus on dengue virus infections. Dengue virus is mosquito transmitted. It puts half the world at risk of infection. Of course, dengue is a climate-driven disease. Climate change is already making diseases worse. Dengue virus is going farther north and south and up to higher elevations.

Globally, dengue viruses cause 100 million infections and 50 million symptomatic cases annually. In 2024, we had the biggest outbreak of dengue in the U.S. There were more than 10,000 cases. The lab’s mission has been to focus on neglected tropical diseases to combat global health inequities through research and solutions like vaccines, therapies, and community-engaged interventions.

In 2004, Eva and her Nicaraguan colleagues established a cohort of 4,000 children in Nicaragua who get sampled every year, and we can now observe distinct sequences of natural infections. Once we understand what protects some children, we can better target our vaccine designs.

What attracted you to working at UC Berkeley for your postdoc?

I was born in India and immigrated to the U.S. My family had to come out of poverty — my grandfather had to work in a textile mill and on the streets of Bombay selling vegetables — and I can see traveling back and forth between India and the U.S. that infectious diseases disproportionately impact poor people. Even during COVID, essential workers were still out and about and had to do their work. So the problem of infectious diseases feels like a personal struggle for me. I thought, “what can I do to make a difference?”

I was excited to work at UC Berkeley because of its rich history of leadership that has advanced public health. Eva's personal mission aligns with mine because it's about connecting science to society. It's not science in a silo. UC Berkeley has been a leader in reaching out to communities, engaging participants, and empowering people with their own health knowledge. UC Berkeley has also been a leader in providing more social good through their innovations.

Have you conducted any fieldwork as part of your work at UC Berkeley?

Yes, I've been to Nicaragua twice. Eva has developed a big team through decades of investment. There are physicians, clinicians, epidemiologists, database managers, lab-based technicians, and field teams. It was amazing to see that type of capacity to detect and diagnose disease, collect clinical data, and analyze epidemics live.

The reason we have to do this in Nicaragua and not in the U.S. is because dengue is endemic in Nicaragua. If we were to sample for dengue cases in the U.S., we would have to sample millions of people, but in Nicaragua, we can get by with sampling 4,000 people because it's that frequent there.

What precautions do you need to take when dealing with dengue in the lab and the field?

In our lab, when we work with viruses, we wear two layers of gloves, a lab coat, and we’re behind the screen of the biosafety cabinet. We only open these samples inside a biosafety cabinet. Anything that touches the virus or a human sample gets deactivated in 10% bleach, and all the materials that touch viruses are enclosed, double bagged, and autoclaved before being tossed. We do all of that to keep people safe.

A woman points to a circular, spotted image on a computer screen

TULIKA SINGH ANALYZES FLUORESCENT MARKERS TO TRACK VIRUSES

PHOTO: FAHD NAUFAL

There’s no effective vaccine for dengue in the U.S., so you protect yourself from mosquito bites and you wear full sleeves even on a hot day and night.

Have you had any disruptions to your funding?

This has been a really bad time for science since January 2025. For most of last year, every week, we got new guidance, new rules. Our NIH [National Institutes of Health] grants were essentially frozen for months because of our research collaborations with Nicaraguan and international colleagues. They did not even give us the next fiscal year of money on time for grants they had already approved. This has been really detrimental. They added a lot of restrictions on foreign collaborations and on using research funding outside the U.S. We were in great uncertainty about when our grants would come back online, and we lost millions in funding for our Nicaraguan studies. That's really troubling.

Eva was contacting the NIH constantly to try to get these grants moving again, but for a long time they were barely responsive.

From my understanding, most of our lab members are supported by NIH grants. This includes funding for graduate students, postdocs, technicians, and program managers in our lab at UC Berkeley. The salaries come from these NIH research grants, so we were in a hard position because jobs are at stake, and people didn’t know what's going to happen in the next few months. Currently, we are initiating collaborations for European funding to help fund the Pediatric Dengue Cohort Study in Nicaragua but we have a very long way to go to replace the lost NIH funding and we also still need to raise more funds for our lab here at UC Berkeley.

And if the research program in Nicaragua goes away, you don't have much to work with.

Exactly. Also, the research supplies that we use are funded by NIH, so all of my projects are NIH-funded.

A woman wearing gloves and a lab coat looks into a microscope

TULIKA SINGH LOOKS THROUGH A MICROSCOPE

PHOTO: FAHD NAUFAL

Zika and dengue are closely related. Does a discovery with one virus have a good chance of transferring to others?

Yes! Many types of flaviruses are human pathogens, not just dengue viruses and Zika. It's also West Nile virus, yellow fever, and Japanese encephalitis virus. These are already endemic globally, and West Nile virus is here in the U.S. The immune response from one of these viruses can alter your likelihood of being protected against the other one. They have this cross-reactive immunity that in some cases is good, in other cases is bad. We don't know exactly how that works yet, but we have made exciting advances in our understanding.

My Ph.D. was on Zika virus and the immune response in children and pregnant women. Currently, I'm applying those same tools to understand dengue virus immune responses and how Zika and dengue can interact with each other immunologically. Because of Eva's research program we know that one Zika exposure increases the risk for severe dengue disease in the next exposure. I'm trying to understand how the prior Zika infection differentially modulates dengue immunity. We are also studying chikungunya virus infections in our cohort.

Do you have a sense of how responsive Zika and dengue are to various platforms?

Currently, live-attenuated vaccine platforms that include multiple serotypes of dengue virus are being tested. Vaccinated individuals certainly respond to these vaccines by creating virus-reactive antibodies, but we don’t know yet if all these antibodies are going to be protective. The challenge is that dengue virus takes your first immune response and uses it to its advantage. One infection can make your second infection worse, when the antibodies from the first infection should have protected you. Dengue is subverting our immune response and making our next disease even worse in some cases. So it's really complicated to develop a vaccine for dengue. This has been an effort for over 30 years.

Now we are finally at the point of figuring out the exact antibody responses required for protection, but we're facing this huge loss of funding, and many scientists are leaving the academic pipeline. I'm really nervous about that, because you're losing decades of investment in training the next generation of scientists. Then who's going to solve the problems?

Large storage tanks arranged in a large room

LIQUID NITROGEN TANKS STORE CRYOPRESERVED CELLS IN NICARAGUA.

PHOTO: TULIKA SINGH

Are there any lines of virus disease research that you find particularly promising?

Our research to understand protective antibody responses against dengue is promising. We’re informing both the CDC and the WHO with our sequential infection data to show what types of infection histories are associated with risk versus protection.There are some vaccines that are coming through phase 3 trials or being licensed in some countries, and the CDC called up Eva to provide data from our cohort to help the FDA make decisions on dengue vaccines in the U.S.

How did COVID-19 change the nature of zoonotic disease research?

Coronavirus brought a lot more attention to infectious disease research. In some ways, it has been a plus because, for a moment, it increased funding and the willingness to collaborate and share information. The amount of public databases that went up in response to solving this crisis together was incredible.

But now we are seeing funding cuts and distrust in science, and it's breaking down the collaborations and information-sharing capacity that we had built in a time of need, not to mention the destruction of multiple databases and public health surveillance systems. It feels like an exaggerated panic-and-neglect cycle. What we needed was long-term, sustained commitments from the federal government. The government has pulled back instead of investing in infectious disease research.

The mRNA vaccine development took only two months to have the first in-human injection. It was the fastest solution vaccinologists have developed, but that would not have been possible without decades of basic research discoveries. That has to be recognized. The NIH is being shortsighted by cutting support for basic science research, which was the foundation for all of this knowledge.

What do you wish more leaders realized about infectious disease research?

I'm afraid that many of our policies are making us more isolationist. We can't continue to build therapies and vaccines and protect the public without global collaborations. Trust was so hard to build, and it's very easy to lose. After we built all this infrastructure, it's not right to take it all away at once. It's a huge risk, and it's not going to be possible to rebuild that without further decades of investment and relationship building.

Borders are not going to stop diseases. Ultimately, we are part of the same planet. We have to collaborate globally to solve these big problems.

Borders are not going to stop diseases. Ultimately, we are part of the same planet. We have to collaborate globally to solve these big problems.

Tulika Singh

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