Why Neglected Tropical Diseases Should Matter to Americans
Daisy Hernández was five years old when one of her favorite aunts was struck with a mysterious illness. Tía Dora had stayed behind in Colombia when Daisy's mother immigrated to Union City, New Jersey. A schoolteacher in her late 20s, she began suffering from fevers and abdominal pain, and her belly grew so big that people thought she was pregnant. Exploratory surgery revealed that her large intestine had swollen to ten times its normal size, and she was fitted with a colostomy bag. Doctors couldn't identify the underlying problem—but whatever it was, they said, it would likely kill her within a year or two.
Tía Dora's sisters in New Jersey—Hernández's mother and two other aunts—weren't about to let that happen. They pooled their savings and flew her to New York City, where a doctor at Columbia-Presbyterian Medical Center with a penchant for obscure ailments provided a diagnosis: Chagas disease. Transmitted by the bite of triatomine insects, commonly known as kissing bugs, Chagas is endemic in many parts of Latin America. It's caused by the parasite Trypanoma cruzi, which usually settles in the heart, where it feeds on muscle tissue. In some cases, however, it attacks the intestines or esophagus. Tía Dora belonged to that minority.
In 1980, U.S. immigration laws were more forgiving than they are today. Tía Dora was able to have surgery to remove a part of her colon, despite not being a citizen or having a green card. She eventually married a legal resident and began teaching Spanish at an elementary school. Over the next three decades, she earned a graduate degree, built a career, and was widowed. Meanwhile, Chagas continued its slow devastation. "Every couple of years, we were back in the hospital with her," Hernández recalls. "When I was in high school, she started feeling like she couldn't swallow anything. It was the parasite, destroying the muscles of her esophagus."
When Tía Dora died in 2010, at 59, her niece was among the family members at her bedside. By then, Hernández had become a journalist and fiction writer. Researching a short story about Chagas disease, she discovered that it affected an estimated 6 million people in South America, Central America, and Mexico—as well as 300,000 in the United States, most of whom were immigrants from those places. "I was shocked to learn it wasn't rare," she says. "That made me hungry to know more about this disease, and about the families grappling with it."
Hernández's curiosity led her to write The Kissing Bug, a lyrical hybrid of memoir and science reporting that was published in June. It also led her to another revelation: Chagas is not unique. It's among the many maladies that global health experts refer to as neglected tropical diseases—often-disabling illnesses that afflict 1.7 billion people worldwide, while getting notably less attention than the "big three" of HIV/AIDs, malaria, and tuberculosis. NTDs cause fewer deaths than those plagues, but they wreak untold suffering and economic loss.
Shortly before Hernández's book hit the shelves, the World Health Organization released its 2021-2030 roadmap for fighting NTDs. The plan sets targets for controlling, eliminating, or eradicating all the diseases on the WHO's list, through measures ranging from developing vaccines to improving healthcare infrastructure, sanitation, and access to clean water. Experts agree that for the campaign to succeed, leadership from wealthy nations—particularly the United States—is essential. But given the inward turn of many such countries in recent years (evidenced in movements ranging from America First to Brexit), and the continuing urgency of the COVID-19 crisis, public support is far from guaranteed.
As Hernández writes: "It is easier to forget a disease that cannot be seen." NTDs primarily affect residents of distant lands. They kill only 80,000 people a year, down from 204,000 in 1990. So why should Americans to bother to look?
Breaking the circle of poverty and disease
The World Health Organization counts 20 diseases as NTDs. Along with Chagas, they include dengue and chikungunya, which cause high fevers and agonizing pain; elephantiasis, which deforms victims' limbs and genitals; onchocerciasis, which causes blindness; schistosomiasis, which can damage the heart, lungs, brain, and genitourinary system; helminths such as roundworm and whipworm, which cause anemia, stunted growth, and cognitive disabilities; and a dozen more. Such ailments often co-occur in the same patient, exacerbating each other's effects and those of illnesses such as malaria.
NTDs may be spread by insects, animals, soil, or tainted water; they may be parasitic, bacterial, viral, or—in the case of snakebite envenoming—non-infectious. What they have in common is their longtime neglect by public health agencies and philanthropies. In part, this reflects their typically low mortality rates. But the biggest factor is undoubtedly their disempowered patient populations.
"These diseases occur in the setting of poverty, and they cause poverty, because of their chronic and debilitating effects," observes Peter Hotez, dean of the National School of Tropical Medicine at Baylor University and co-director of the Texas Children's Hospital for Vaccine Development. And historically, the everyday miseries of impoverished people have seldom been a priority for those who set the global health agenda.
That began to change about 20 years ago, when Hotez and others developed the conceptual framework for NTDs and early proposals for combating them. The WHO released its first roadmap in 2012, targeting 17 NTDs for control, elimination, or eradication by 2020. (Rabies, snakebite, and dengue were added later.) Since then, the number of people at risk for NTDs has fallen by 600 million, and 42 countries have eliminated at least one such disease. Cases of dracunculiasis—known as Guinea worm disease, for the parasite that creates painful blisters in a patient's skin—have dropped from the millions to just 27 in 2020.
Yet the battle is not over, and the COVID-19 pandemic has disrupted prevention and treatment programs around the globe.
A new direction — and longstanding obstacles
The WHO's new roadmap sets even more ambitious goals for 2030. Among them: reducing by 90 percent the number of people requiring treatment for NTDs; eliminating at least one NTD in another 100 countries; and fully eradicating dracunculiasis and yaws, a disfiguring skin infection.
The plan also places an increased focus on "country ownership," relying on nations with high incidence of NTDs to design their own plans based on local expertise. "I was so excited to see that," says Kristina Talbert-Slagle, director of the Yale College Global Health Studies program. "No one is a better expert on how to address these situations than the people who deal with it day by day."
Another fresh approach is what the roadmap calls "cross-cutting" targets. "One of the really cool things about the plan is how much it emphasizes coordination among different sectors of the health system," says Claire Standley, a faculty member at Georgetown University's Center for Global Health Science and Security. "For example, it explicitly takes into account the zoonotic nature of many neglected tropical diseases—the fact that we have to think about animal health as well as human health when we tackle NTDs."
Whether this grand vision can be realized, however, will depend largely on funding—and that, in turn, is a question of political will in the countries most able to provide it. On the upside, the U.S. has ended its Trump-era feud with the WHO. "One thing that's been really encouraging," says Standley, "has been the strong commitment toward global cooperation from the current administration." Even under the previous president, the U.S. remained the single largest contributor to the global health kitty, spending over $100 million annually on NTDs—six times the figure in 2006, when such financing started.
On the downside, America's outlay has remained flat for several years, and the Biden administration has so far not moved to increase it. A "back-of-the-envelope calculation," says Hotez, suggests that the current level of aid could buy medications for the most common NTDs for about 200 million people a year. But the number of people who need treatment, he notes, is at least 750 million.
Up to now, the United Kingdom—long the world's second-most generous health aid donor—has taken up a large portion of the slack. But the UK last month announced deep cuts in its portfolio, eliminating 102 previously supported countries and leaving only 34. "That really concerns me," Hotez says.
The struggle for funds, he notes, is always harder for projects involving NTDs than for those aimed at higher-profile diseases. His lab, which he co-directs with microbiologist Maria Elena Bottazzi, started developing a COVID-19 vaccine soon after the pandemic struck, for example, and is now in Phase 3 trials. The team has been working on vaccines for Chagas, hookworm, and schistosomiasis for much longer, but trials for those potential game-changers lag behind. "We struggle to get the level of resources needed to move quickly," Hotez explains.
Two million reasons to care
One way to prompt a government to open its pocketbook is for voters to clamor for action. A longtime challenge with NTDs, however, has been getting people outside the hardest-hit countries to pay attention.
The reasons to care, global health experts argue, go beyond compassion. "When we have high NTD burden," says Talbert-Slagle, "it can prevent economic growth, prevent innovation, lead to more political instability." That, in turn, can lead to wars and mass migration, affecting economic and political events far beyond an affected country's borders.
Like Hernández's aunt Dora, many people driven out of NTD-wracked regions wind up living elsewhere. And that points to another reason to care about these diseases: Some of your neighbors might have them. In the U.S., up to 14 million people suffer from neglected parasitic infections—including 70,000 with Chagas in California alone.
When Hernández was researching The Kissing Bug, she worried that such statistics would provide ammunition to racists and xenophobes who claim that immigrants "bring disease" or exploit overburdened healthcare systems. (This may help explain some of the stigma around NTDs, which led Tía Dora to hide her condition from most people outside her family.) But as the book makes clear, these infections know no borders; they flourish wherever large numbers of people lack access to resources that most residents of rich countries take for granted.
Indeed, far from gaming U.S. healthcare systems, millions of low-income immigrants can't access them—or must wait until they're sick enough to go to an emergency room. Since Congress changed the rules in 1996, green card holders have to wait five years before they can enroll in Medicaid. Undocumented immigrants can never qualify.
Closing the great divide
Hernández uses a phrase borrowed from global health crusader Paul Farmer to describe this access gap: "the great epi divide." On one side, she explains, "people will die from cancer, from diabetes, from chronic illnesses later in life. On the other side of the epidemiological divide, people are dying because they can't get to the doctor, or they can't get medication. They don't have a hospital anywhere near them. When I read Dr. Farmer's work, I realized how much that applied to neglected diseases as well."
When it comes to Chagas disease, she says, the epi divide is embodied in the lack of a federal mandate for prenatal or newborn screening. Each year, according to the Centers for Disease Control and Prevention, up to 300 babies in the U.S. are born with Chagas, which can be passed from the mother in utero. The disease can be cured with medication if treated in infancy. (It can also be cured in adults in the acute stage, but is seldom detected in time.) Yet the CDC does not require screening for Chagas—even though newborns are tested for 15 diseases that are less common. According to one study, it would be 10 times cheaper to screen and treat babies and their mothers than to cover the costs related to the illness in later years. Few states make the effort.
The gap that enables NTDs to persist, Hernández argues, is the same one that has led to COVID-19 death rates in Black and Latinx communities that are double those elsewhere in America. To close it, she suggests, caring is not enough.
"When I was working on my book," she says, "I thought about HIV in the '80s, when it had so much stigma that no one wanted to talk about it. Then activists stepped up and changed the conversation. I thought a lot about breast cancer, which was stigmatized for years, until people stepped forward and started speaking out. I thought about Lyme disease. And it wasn't only patients—it was also allies, right? The same thing needs to happen with neglected diseases around the world. Allies need to step up and make demands on policymakers. We need to make some noise."
Want to Motivate Vaccinations? Message Optimism, Not Doom
After COVID-19 was declared a worldwide pandemic by the World Health Organization on March 11, 2020, life as we knew it altered dramatically and millions went into lockdown. Since then, most of the world has had to contend with masks, distancing, ventilation and cycles of lockdowns as surges flare up. Deaths from COVID-19 infection, along with economic and mental health effects from the shutdowns, have been devastating. The need for an ultimate solution -- safe and effective vaccines -- has been paramount.
On November 9, 2020 (just 8 months after the pandemic announcement), the press release for the first effective COVID-19 vaccine from Pfizer/BioNTech was issued, followed by positive announcements regarding the safety and efficacy of five other vaccines from Moderna, University of Oxford/AztraZeneca, Novavax, Johnson and Johnson and Sputnik V. The Moderna and Pfizer vaccines have earned emergency use authorization through the FDA in the United States and are being distributed. We -- after many long months -- are seeing control of the devastating COVID-19 pandemic glimmering into sight.
To be clear, these vaccine candidates for COVID-19, both authorized and not yet authorized, are highly effective and safe. In fact, across all trials and sites, all six vaccines were 100% effective in preventing hospitalizations and death from COVID-19.
All Vaccines' Phase 3 Clinical Data
Complete protection against hospitalization and death from COVID-19 exhibited by all vaccines with phase 3 clinical trial data.
This astounding level of protection from SARS-CoV-2 from all vaccine candidates across multiple regions is likely due to robust T cell response from vaccination and will "defang" the virus from the concerns that led to COVID-19 restrictions initially: the ability of the virus to cause severe illness. This is a time of hope and optimism. After the devastating third surge of COVID-19 infections and deaths over the winter, we finally have an opportunity to stem the crisis – if only people readily accept the vaccines.
Amidst these incredible scientific advancements, however, public health officials and politicians have been pushing downright discouraging messaging. The ubiquitous talk of ongoing masks and distancing restrictions without any clear end in sight threatens to dampen uptake of the vaccines. It's imperative that we break down each concern and see if we can revitalize our public health messaging accordingly.
The first concern: we currently do not know if the vaccines block asymptomatic infection as well as symptomatic disease, since none of the phase 3 vaccine trials were set up to answer this question. However, there is biological plausibility that the antibodies and T-cell responses blocking symptomatic disease will also block asymptomatic infection in the nasal passages. IgG immunoglobulins (generated and measured by the vaccine trials) enter the nasal mucosa and systemic vaccinations generate IgA antibodies at mucosal surfaces. Monoclonal antibodies given to outpatients with COVID-19 hasten viral clearance from the airways.
Although it is prudent for those who are vaccinated to wear masks around the unvaccinated in case a slight risk of transmission remains, two fully vaccinated people can comfortably abandon masking around each other.
Moreover, data from the AztraZeneca trial (including in the phase 3 trial final results manuscript), where weekly self-swabbing was done by participants, and data from the Moderna trial, where a nasal swab was performed prior to the second dose, both showed risk reductions in asymptomatic infection with even a single dose. Finally, real-world data from a large Pfizer-based vaccine campaign in Israel shows a 50% reduction in infections (asymptomatic or symptomatic) after just the first dose.
Therefore, the likelihood of these vaccines blocking asymptomatic carriage, as well as symptomatic disease, is high. Although it is prudent for those who are vaccinated to wear masks around the unvaccinated in case a slight risk of transmission remains, two fully vaccinated people can comfortably abandon masking around each other. Moreover, as the percentage of vaccinated people increases, it will be increasingly untenable to impose restrictions on this group. Once herd immunity is reached, these restrictions can and should be abandoned altogether.
The second concern translating to "doom and gloom" messaging lately is around the identification of troubling new variants due to enhanced surveillance via viral sequencing. Four major variants circulating at this point (with others described in the past) are the B.1.1.7 variant ("UK variant"), B.1.351 ("South Africa variant), P.1. ("Brazil variant"), and the L452R variant identified in California. Although the UK variant is likely to be more transmissible, as is the South Africa variant, we have no reason to believe that masks, distancing and ventilation are ineffective against these variants.
Moreover, neutralizing antibody titers with the Pfizer and Moderna vaccines do not seem to be significantly reduced against the variants. Finally, although the Novavax 2-dose and Johnson and Johnson (J&J) 1-dose vaccines had lower rates of efficacy against moderate COVID-19 disease in South Africa, their efficacy against severe disease was impressively high. In fact J&J's vaccine still prevented 100% of hospitalizations and death from COVID-19. When combining both hospitalizations/deaths and severe symptoms managed at home, the J&J 1-dose vaccine was 85% protective across all three sites of the trial: the U.S., Latin America (including Brazil), and South Africa.
In South Africa, nearly all cases of COVID-19 (95%) were due to infection with the B.1.351 SARS-CoV-2 variant. Finally, since herd immunity does not rely on maximal immune responses among all individuals in a society, the Moderna/Pfizer/J&J vaccines are all likely to achieve that goal against variants. And thankfully, all of these vaccines can be easily modified to boost specifically against a new variant if needed (indeed, Moderna and Pfizer are already working on boosters against the prominent variants).
The third concern of some public health officials is that people will abandon all restrictions once vaccinated unless overly cautious messages are drilled into them. Indeed, the false idea that if you "give people an inch, they will take a mile" has been misinforming our messaging about mitigation since the beginning of the pandemic. For example, the very phrase "stay at home" with all of its non-applicability for essential workers and single individuals is stigmatizing and unrealistic for many. Instead, the message should have focused on how people can additively reduce their risks under different circumstances.
The public will be more inclined to trust health officials if those officials communicate with nuanced messages backed up by evidence, rather than with broad brushstrokes that shame. Therefore, we should be saying that "vaccinated people can be together with other vaccinated individuals without restrictions but must protect the unvaccinated with masks and distancing." And we can say "unvaccinated individuals should adhere to all current restrictions until vaccinated" without fear of misunderstandings. Indeed, this kind of layered advice has been communicated to people living with HIV and those without HIV for a long time (if you have HIV but partner does not, take these precautions; if both have HIV, you can do this, etc.).
Our heady progress in vaccine development, along with the incredible efficacy results of all of them, is unprecedented. However, we are at risk of undermining such progress if people balk at the vaccine because they don't believe it will make enough of a difference. One of the most critical messages we can deliver right now is that these vaccines will eventually free us from the restrictions of this pandemic. Let's use tiered messaging and clear communication to boost vaccine optimism and uptake, and get us to the goal of close human contact once again.
Inside Scoop: How a DARPA Scientist Helped Usher in a Game-Changing Covid Treatment
Amy Jenkins was in her office at DARPA, a research and development agency within the Department of Defense, when she first heard about a respiratory illness plaguing the Chinese city of Wuhan. Because she's a program manager for DARPA's Biological Technologies Office, her colleagues started stopping by. "It's really unusual, isn't it?" they would say.
At the time, China had a few dozen cases of what we now call COVID-19. "We should maybe keep an eye on that," she thought.
Early in 2020, still just keeping watch, she was visiting researchers working on DARPA's Pandemic Prevention Platform (P3), a project to develop treatments for "any known or previously unknown infectious threat," within 60 days of its appearance. "We looked at each other and said, 'Should we be doing something?'" she says.
For projects like P3, groups of scientists—often at universities and private companies—compete for DARPA contracts, and program managers like Jenkins oversee the work. Those that won the P3 bid included scientists at AbCellera Biologics, Inc., AstraZeneca, Duke University, and Vanderbilt University.
At the time Jenkins was talking to the P3 performers, though, they didn't have evidence of community transmission. "We would have to cross that bar before we considered doing anything," she says.
The world soon leapt far over that bar. By the time Jenkins and her team decided P3 should be doing something—with their real work beginning in late February--it was too late to prevent this pandemic. But she could help P3 dig into the chemical foundations of COVID-19's malfeasance, and cut off its roots. That work represents, in fact, her roots.
In late February 2020, DARPA received a single blood sample from a recovered COVID-19 patient, in which P3 researchers could go fishing for antibodies. The day it arrived, Jenkins's stomach roiled. "We get one shot," she thought.
Fighting the Smallest Enemies
Jenkins, who's in her early 40s, first got into germs the way many 90s kids did: by reading The Hot Zone, a novel about a hemorrhagic fever gone rogue. It wasn't exactly the disintegrating organs that hooked her. It was the idea that "these very pathogens that we can't even see can make us so sick and bring us to our knees," she says. Reading about scientists facing down deadly disease, she wondered, "How do these things make you so sick?"
She chased that question in college, majoring in both biomolecular science and chemistry, and later became an antibody expert. Antibodies are proteins that hook to a pathogen to block it from attaching to your cells, or tag it for destruction by the rest of the immune system. Soon, she jumped on the "monoclonal antibodies" train—developing synthetic versions of these natural defenses, which doctors can give to people to help them battle an early-stage infection, and even to prevent an infection from taking root after an exposure.
Jenkins likens the antibody treatments to the old aphorism about fishing: Vaccines teach your body how to fish, but antibodies simply give your body the pesca-fare. While that, as the saying goes, won't feed you for a lifetime, it will last a few weeks or months. Monoclonal antibodies thus are a promising preventative option in the immediate short-term when a vaccine hasn't yet been given (or hasn't had time to produce an immune response), as well as an important treatment weapon in the current fight. After former president Donald Trump contracted COVID-19, he received a monoclonal antibody treatment from biotech company Regeneron.
As for Jenkins, she started working as a DARPA Biological Technologies Office contractor soon after completing her postdoc. But it was a suit job, not a labcoat job. And suit jobs, at first, left Jenkins conflicted, worried about being bored. She'd give it a year, she thought. But the year expired, and bored she was not. Around five years later, in June 2019, the agency hired her to manage several of the office's programs. A year into that gig, the world was months into a pandemic.
The Pandemic Pivot
At DARPA, Jenkins inherited five programs, including P3. P3 works by taking blood from recovered people, fishing out their antibodies, identifying the most effective ones, and then figuring out how to manufacture them fast. Back then, P3 existed to help with nebulous, future outbreaks: Pandemic X. Not this pandemic. "I did not have a crystal ball," she says, "but I will say that all of us in the infectious diseases and public-health realm knew that the next pandemic was coming."
Three days after a January 2020 meeting with P3 researchers, COVID-19 appeared in Seattle, then began whipping through communities. The time had come for P3 teams to swivel. "We had done this," she says. "We had practiced this before." But would their methods stand up to something unknown, racing through the global population? "The big anxiety was, 'Wow, this was real,'" says Jenkins.
While facing down that realness, Jenkins was also managing other projects. In one called PREPARE, groups develop "medical countermeasures" that modulate a person's genetic code to boost their bodies' responses to threats. Another project, NOW, envisions shipping-container-sized factories that can make thousands of vaccine doses in days. And then there's Prometheus—which means "forethought" in Greek, and is the name of the god who stole fire and gave it to humans. Wrapping up as COVID ramped up, Prometheus aimed to identify people who are contagious—with whatever—before they start coughing, and even if they never do.
All of DARPA's projects focus on developing early-stage technology, passing it off to other agencies or industry to put it into operation. The orientation toward a specific goal appealed to Jenkins, as a contrast to academia. "You go down a rabbit hole for years at a time sometimes, chasing some concept you found interesting in the lab," she says. That's good for the human pursuit of knowledge, and leads to later applications, but DARPA wants a practical prototype—stat.
"Dual-Use" Technologies
That desire, though, and the fact that DARPA is a defense agency, present philosophical complications. "Bioethics in the national-security context turns all the dials up to 10+," says Jonathan Moreno, a medical ethicist at the University of Pennsylvania.
While developing antibody treatments to stem a pandemic seems straightforwardly good, all biological research—especially that backed by military money—requires evaluating potential knock-on applications, even those that might come from outside the entity that did the developing. As Moreno put it, "Albert Einstein wasn't thinking about blowing up Hiroshima." Particularly sensitive are so-called "dual-use" technologies—those tools that could be used for both benign and nefarious purposes, or are of interest to both the civilian and military worlds.
Moreno takes Prometheus itself as an example of "dual-use" technology. "Think about somebody wearing a suicide vest. Instead of a suicide vest, make them extremely contagious with something. The flu plus Ebola," he says. "Send them someplace, a sensitive environment. We would like to be able to defend against that"—not just tell whether Uncle Fred is bringing asymptomatic COVID home for Christmas. Prometheus, Jenkins says, had safety in mind from the get-go, and required contenders to "develop a risk mitigation plan" and "detail their strategy for appropriate control of information."
To look at a different program, if you can modulate genes to help healing, you probably know something (or know someone else could infer something) about how to hinder healing. Those sorts of risks are why PREPARE researchers got their own "ethical, legal, and social implications" panel, which meets quarterly "to ensure that we are performing all research and publications in a safe and ethical manner," says Jenkins.
DARPA as a whole, Moreno says, is institutionally sensitive to bioethics. The agency has ethics panels, and funded a 2014 National Academies assessment of how to address the "ethical, legal, and societal issues" around technology that has military relevance. "In the cases of biotechnologies where some of that research brushes up against what could legitimately be considered dual-use, that in itself justifies our investment," says Jenkins. "DARPA deliberately focuses on safety and countermeasures against potentially dangerous technologies, and we structure our programs to be transparent, safe, and legal."
Going Fishing
In late February 2020, DARPA received a single blood sample from a recovered COVID-19 patient, in which P3 researchers could go fishing for antibodies. The day it arrived, Jenkins's stomach roiled. "We get one shot," she thought.
As scientists from the P3-funded AbCellera went through the processes they'd practiced, Jenkins managed their work, tracking progress and relaying results. Soon, the team had isolated a suitable protein: bamlanivimab. It attaches to and blocks off the infamous spike proteins on SARS-CoV-2—those sticky suction-cups in illustrations. Partnering with Eli Lilly in a manufacturing agreement, the biotech company brought it to clinical trials in May, just a few months after its work on the deadly pathogen began, after much of the planet became a hot zone.
On November 10—Jenkins's favorite day at the (home) office—the FDA provided Eli Lilly emergency use authorization for bamlanivimab. But she's only mutedly screaming (with joy) inside her heart. "This pandemic isn't 'one morning we're going to wake up and it's all over,'" she says. When it is over, she and her colleagues plan to celebrate their promethean work. "I'm hoping to be able to do it in person," she says. "Until then, I have not taken a breath."