Q&A with Councilor Eva Harris on battle against Zika

Posted 15 April 2016

"It’s really very impressive what’s going on. We’re seeing multidisciplinary scientific collaborations and interagency collaborations. Scientists in different silos are coming together around this problem, motivated by the public health urgency and the need for answers in a short time span." - Eva Harris, PhD

Eva Harris, PhD, is Professor, Division of Infectious Diseases and Vaccinology, School of Public Health and Director, Center for Global Public Health, University of California, Berkeley. Her international work focuses on laboratory-based and epidemiological studies of dengue, chikungunya, and influenza in endemic Latin American countries, particularly in Nicaragua. Dr. Harris received a MacArthur “Genius” Award for her pioneering work developing programs and working to build scientific capacity in developing countries. She is the founder and president of the Sustainable Sciences Institute.

It appears as though there are major collaboration efforts taking place with Zika. What can you tell us about it?
It’s really very impressive what’s going on. We’re seeing multidisciplinary scientific collaborations and interagency collaborations. Scientists in different silos are coming together around this problem, motivated by the public health urgency and the need for answers in a short time span. There are so many questions about Zika, and researchers are coming together in the virology, immunology, neurobiology, developmental biology and entomology fields, and adapting different animal models. 
We’re also seeing journals turn manuscripts around quickly, being very flexible and even asking for one- to two-day reviews, which I’ve never seen before. NIH is getting funding out the door really quickly using  grant supplements and a new rapid-review R21 mechanism. In regard to agencies, for example, I’m involved in a multi-site pregnancy study in a number of Latin American countries sponsored by NIAID together with NICHD (National Institute of Child Health and Development). The study is taking place at ongoing field sites, and bringing in further collaboration with CDC and other international health bodies. I’m also involved in a consortium of Zika pregnancy studies that brings together the WHO, PAHO, CDC, European Union, NIH, and Institut Pasteur to harmonize protocols. If we want to deal with Zika quickly, we have to harmonize protocols, instead of having one study here and another there. It’s remarkable how people are pulling together globally.
What are the current challenges and what are the long-term challenges of fighting Zika?
The challenges are enormous. First, the diagnostic challenge. In terms of the molecular diagnosis of dengue, chikungunya and Zika, we’re doing OK as there are several triplex assays available. The real problems are the serological assays – looking for antibodies – for diagnosis, screening and surveillance. With Zika, after the first four days of illness you need serology for diagnosis; but there is enormous cross-reactivity with dengue and other flaviviruses, especially with secondary responses – and almost all adults in Latin America have had previous dengue infections.
Second, there is an ongoing crisis in congenital birth defects. We know now that Zika virus poses a risk, but we don’t know how much of a risk. We don’t know what to tell women what their risks are, even when they have a symptomatic Zika infection. We really don’t know what the risk is with an asymptomatic infection. This is further compounded by the fact that we can say, “You should monitor more frequently with ultrasound,” but a lot of the abnormalities by ultrasound are discernable only very late in pregnancy.
It’s also difficult to control the mosquito vectors for Zika virus. We have a number of strategies, but they have failed over the decades to control dengue, and they are failing to control Zika. Apparently, Zika vius has the potential to be transmitted by up to 25 different species of mosquito – and that is very frightening. A number of vector control approaches are needed and quickly. The timeline is so intense; we have a completely susceptible population, up to 50 percent of whom could be infected in a single season. That’s a huge infection potential in a very short time. Community-based vector control is very important, but the populations are not being strongly encouraged to derive their own solutions for keeping their households free of clean, standing water. Instead, the only approach they’re hearing about is fumigation. There is no one silver bullet. Integrating different vector control strategies to confront Zika is very important.
Can you talk about some of the ethical challenges that we are facing with Zika?
One major challenge is not having answers, especially in the situation with women who are pregnant or want to become pregnant – what do you tell them? You can tell them they’re positive for Zika, but we don’t know precisely what that means in terms of risk. We want to be transparent and tell them the situation, but we don’t want to worry them unnecessarily. Stress itself is a known risk factor during pregnancy. It’s a messy situation right now because we don’t have a lot of options. Additionally, all of the Latin American countries affected by the Zika pandemic are Catholic and have little access to contraception and little to no access to abortions. Abortion is illegal in many of the countries. So there are enormous social issues and these are big, big problems.
Why is ASTMH the professional home for experts who do this type of work?
ASTMH is where the massive bulk of flavivirologists live, as well as entomologists and epidemiologists. Infectious diseases in tropical areas is what ASTMH does – especially in terms of studying diseases in-country, understanding local issues, and translating from the bench to the field. With Zika, it’s also an incredible opportunity right now to bring in people from other areas who are in other “silos” – placental biologists, neurodevelopment scientists, social scientists, etc. They don’t usually attend the Annual Meeting, but with all the Zika research happening right now, it’s a great chance to invite them to come and participate.