Kat Kelley

2016 was a year that ushered in significant shifts in the global health landscape. We witnessed the waning of the Ebola epidemic and the waxing of the Zika outbreak; important leadership changes among the biggest institutional players in global health; and the development and introduction of new innovations that could turn the tide against leading infectious disease killers. As the year comes to an end, GHTC is reflecting on the top stories in global health innovation that made news in 2016. Here are seven of those top moments: 1. Scientists mobilize against Zika A vial of the National Institute of Allergy and Infectious Diseases (NIAID) Zika Virus Investigational DNA Vaccine (Photo: NIAID).Once considered an obscure virus responsible for a mild illness, Zika took the world by storm in 2016. As the virus gained a foothold in more than 60 countries, its association with devastating birth defects and neurological conditions was firmly established. Prior to Zika’s emergence in the Americas, only 25 research papers had been published on the virus. As the epidemic grew, scientists around the world joined the fight against Zika, often sharing their data and research in real time to speed progress. Thanks to the efforts of these researchers, over the past year our scientific understanding of Zika has grown exponentially, and we have advanced a robust pipeline of new tools to prevent, detect, and treat Zika. Today, there are more than 35 Zika vaccine candidates under development; 13 Zika diagnostics have been authorized for use by the US Food and Drug Administration; and researchers are screening novel compounds and evaluating existing drugs to advance treatments for the disease. 2. The world commits to the fight against antimicrobial resistance United Nations General Assembly (Photo: GHTC/Matthew Robinson). 2016 marked the year the world finally got serious about tackling antimicrobial resistance. On the heels of several major analyses examining the potentially devastating health and economic impact of antimicrobial resistance, the United Nations (UN) General Assembly convened global leaders for a high-level summit on antimicrobial resistance—the fourth time such a meeting has been held on a health-related topic during the UN’s 71-year history. At the close of the summit, UN member states unanimously endorsed and adopted a political declaration committing to developing action plans and policies; mobilizing resources; and supporting public awareness, surveillance, and R&D efforts to combat antimicrobial resistance. It is our hope that 2017 will mark the year political commitment translates to concrete action to advance the development of new antibiotics. 3. New strategies deployed to stymie mosquito-borne diseases Mosquito-borne diseases remain an age-old scourge, but 2016 saw the advancement of several novel strategies to combat these tiny foes. Efforts to combat mosquito-borne diseases with the transmission blocking–bacteria Wolbachia took an important leap forward this year. Past studies have shown that when the Wolbachia bacteria is introduced to Aedes aegypti mosquitos—which carry viruses like Zika and yellow fever—it prevents the viruses from replicating and blocks further transmission. Because the bacteria can be passed from one generation of mosquitoes to the next, the bacteria offers hope for eliminating a virus’s presence within a local mosquito population. After several years of conducting small-scale tests of this method, the Eliminate Dengue Program announced in 2016 it would begin conducting two large-scale trials in South America to determine whether this approach is effective in halting the spread of mosquito-borne diseases in large urban settings. This year the biotech company Oxitec also advanced efforts to test the use of genetically modified mosquitoes to reduce mosquito populations and disease transmission. The company has engineered mosquitoes that mate with A. aegypti mosquitoes, producing offspring that are unable to mature to adulthood. Early last year, Oxitec introduced the mosquitoes into the Brazilian city of Piracicaba, resulting in an 82 percent decrease in the population of A. aegypti mosquitoes in just nine months. Now, Oxitec has expanded the trial to a larger geographical area and is also initiating trials in the Florida Keys and the Cayman Islands. 4. World’s first kid-friendly TB medicine launches Children who receive tuberculosis (TB) medicines require a different dose than adults, yet until this year, there were no TB medicines designed specifically for children, so parents were forced to split or crush adult pills in an attempt to administer the right dose to their child. This year, that all changed with the launch of the world’s first kid-friendly TB medication. Developed by TB Alliance, the medicine is designed with the unique needs of children in mind: It is fruit-flavored, dissolvable in water, easy to administer, and appropriately-dosed. Already, more than 30 countries have adopted the new medicines, and enough orders have been placed to treat half of childhood TB cases worldwide. 5. Unique HIV prevention option for women reaches important development milestone Image captionMonthly vaginal dapivirine ring helps protect women against HIV (Photo: International Partnership for Microbicides). Women may soon have a powerful new tool at their disposal to prevent HIV infection. Earlier this year, the International Partnership for Microbicides (IPM) announced the results of two large phase 3 clinical trials demonstrating that a monthly vaginal ring containing the antiretroviral drug dapivirine can help protect women from HIV. While initial results indicated that the dapivirine ring reduced HIV risk by approximately 30 percent, further analysis revealed that the ring reduced infection rates by 75 percent in women who used the ring consistently. Now, IPM is seeking regulatory approval for the dapivirine ring and is conducting open-label studies, enabling trial participants to continue using the ring as IPM collects additional data. The dapivirine ring is the only long-acting, female-initiated HIV prevention tool to have proven successful in phase 3 clinical trials. Young women in sub-Saharan Africa are more than twice as likely to be infected with HIV than their male counterparts, and thus female-centered prevention tools are needed stem the epidemic. 6. Roll out begins of world’s first malaria vaccine candidate After decades of development and testing, the world’s first malaria vaccine candidate will soon be introduced in several communities in sub-Saharan Africa. The vaccine—RTS,S—was developed by PATH and GlaxoSmithKline and received a positive opinion from the European Medicines Agency last year following completion of phase 3 clinical trials. In November, the World Health Organization (WHO) announced it would pilot and evaluate the vaccine in real-life settings, thanks to funding from The Global Fund; UNITAID; and Gavi, the Vaccine Alliance. Pending results of these pilot tests, WHO will determine whether to deploy the vaccine on a wider scale. 7. New global health technologies advance through the pipeline PATH launches an easy-to-use, rapid diagnostic for onchocerciasis (Photo: PATH/Dunia Faulx) Over the past year, several other promising new health innovations have moved through the development pipeline and one step closer to reaching the hands of patients: Two important health tools—a novel, affordable oral cholera vaccine developed by the International Vaccine Institute, and the Woman’s Condom developed by PATH and partners—received WHO prequalification this year, paving the way for their procurement by UN agencies and other international procurement organizations. Two new rapid diagnostic tests for the neglected tropical diseases onchocerciasis (river blindness) and lymphatic filariasis were launched this year. Developed by PATH, these tests provide results in just 30 minutes and can be stored at a wide range of temperatures. Development has begun for an affordable therapy for hepatitis C. In 2013, the world’s first cures for hepatitis C hit the US market, however, treatment remains out of reach for many patients due to the high price tag. This year, the Drugs for Neglected Diseases initiative announced it would begin testing an alternative therapy in phase 2 and 3 clinical trials, with a guarantee from the manufacturer that, if successful, the entire regimen will be sold for no more than US$294.  As 2016 draws to a close and 2017 begins, it is time for the global health community to redouble our efforts to make sure this vital progress in global health innovation continues to ensure that people around the world will have access to lifesaving and life-improving health technologies.

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. Earlier this year, the World Health Organization released a list of the eight pathogens most likely to cause the next pandemic. All eight are caused by viruses, and all eight are zoonotic—originating in animals. To experts, this came as no surprise: viruses are able to rapidly evolve to infect different species or become more virulent, and nearly three-fourths of new and emerging diseases are zoonotic. Now, researchers are proposing the Global Virome Project, an initiative to characterize every virus in the world (well, 99 percent of them). Tracking down the estimated 1.3 million viruses in the world would cost nearly US$3.4 billion, however, proponents of the project argue that it would unearth insights into viruses en masse and ensure a basic scientific understanding of potential pandemic threats. New research suggests that nearly half of women infected with Zika during pregnancy will have adverse pregnancy outcomes, including miscarriages and birth defects. The study, which enrolled 125 women in Rio de Janeiro, Brazil, is the first to quantify the frequency of these complications among pregnant women who test positive for the virus. Overall, 46 percent of women experienced significant adverse outcomes, however, the true impact may be even higher. The study only followed infants for the first three months of life, but emerging research indicates that neurological and physical defects may develop throughout the first year of life. Further, the study reveals that risk is greatest for women who are infected during the first trimester (55 percent), though adverse outcomes remain common among women infected during the second (51 percent) and third (29 percent) trimester. Antibiotics and immune cells can only target bacteria when they are growing and dividing. Consequently, bacteria often become inactive to evade detection. Many bacteria rely on a toxin antitoxin system to achieve this. A pernicious environmental factor will prompt the bacteria to produce a toxin that puts themselves to sleep, and the abatement of that factor triggers the release of an antitoxin to wake the bacteria back up. Now, an international team of researchers has discovered that the toxin antitoxin system for E. coli, and potentially other bacteria, relies on oxygen to wake up the bacteria. When E. coli cells are dormant, both the antitoxin and oxygen must be present to destroy the original toxin. These findings suggest that oxygen could be the key to developing antibiotics that can wake up and consequently attack dormant bacteria.

The HIV virus is rapidly developing resistance to common antiretroviral drugs. In low- and middle-income countries (LMICs), 10 percent of patients starting antiretroviral therapy (ART) and 40 percent of patients restarting treatment are infected with drug-resistant strains. The leading contributor to drug resistance is failure to adhere to treatment—a problem that plagues nearly three-fourths of patients in LMICs. In low-resource settings, many patients only have access to older, more toxic drugs, and more than one third of clinics report stock outs of HIV medicines. If action is not taken to improve treatment for these patients, drug-resistant strains of HIV-1 could result in 300,000 new infections and 425,000 deaths over the next five years. Last week, the US Congress overwhelmingly approved the nearly 1000-page 21st Century Cures Act, a massive initiative that channels new funding into the US National Institutes of Health and alters the way the US Food and Drug Administration (FDA) regulates certain medicines and devices. While some advocates argue that it weakens the FDA’s regulatory review process, others have applauded the legislation for its potential impact on the development and approval of new antibiotics. One provision—the limited population approval pathway—would allow the FDA to approve antimicrobials and other drugs for serious or life-threatening infections based on smaller clinical trials, addressing the challenge of identifying an adequate number of clinical trial participants (i.e., patients who are infected with drug-resistant pathogens). Another component addresses the FDA’s approach to updating antimicrobial susceptibility interpretative criteria, which informs the development of diagnostics that help physicians prescribe the best antibiotics for a given infection. The provision enables the agency to rely on other organizations’ research and update its criteria accordingly, rather than reviewing the research in house—a time consuming and costly process. While the legislation will likely be signed into law by President Obama, it could take years to fully implement. Scientists have long known that the tuberculosis vaccine offers protection against a number of pathogens and even treats certain conditions (i.e., bladder cancer and asthma), and a recent study in Cell Reports may explain why. Studies in mice and humans revealed that the Bacillus Calmette-Guerin vaccine increased glycolysis—the process of breaking down glucose—in monocytes, a type of immune cell. The effect, which lasts long after vaccination, enhances monocytes’ immunological memory—their ability to remember pathogens they have previously encountered—improving their disease detection and response capabilities. These findings could help scientists devise new strategies for boosting the immune system or its response to certain diseases. The European Medicines Agency (EMA) released a statement last week indicating that patients treated with certain hepatitis C medicines may experience a resurgence of previously latent hepatitis B. The phenomenon applies to a new class of drugs known as direct-acting antivirals and includes Daklinza, Exviera, Harvoni, Olysio, Sovaldi, and Viekirax. While there have only been 30 reported cases, the EMA is recommending patients be tested for hepatitis B before starting treatment.

Scientists at University of California, San Francisco have identified several drugs that block the Zika virus from infecting brain cells. After determining the types of brain cells susceptible to Zika, the researchers screened more than 2,000 Food and Drug Administration–approved medicines for their ability to protect these cells from the virus. The project revealed that azithromycin, a commonly used antibiotic, could provide protection against Zika in laboratory-grown brain cells. Not only is azithromycin widely available, it is also safe for use in pregnant women, an important characteristic as Zika infection during pregnancy can impede fetal development and result in devastating birth defects. An existing drug for gastrointestinal disorders has shown promise in treating and potentially even curing HIV in monkeys. Existing treatment—antiretroviral therapy (ART)—suppresses HIV, making the virus nearly undetectable in the blood, however, adherence is critical as just a few weeks off of treatment can result in a resurgence of the virus. Due to the demands of adherence and the expensive and toxic nature of many of these medicines, only one third of patients in the United States manage to keep the virus at these undetectable levels. Now researchers may have found a “functional cure” for HIV. The drug—vedolizumab—is approved to treat ulcerative colitis and Crohn's disease in more than 50 countries. In preclinical trials, vedolizumab kept the virus at bay in monkeys for up to two years after cessation of treatment. The National Institutes of Health recently initiated human clinical trials in which people living with HIV and AIDS will receive infusions of vedolizumab every four weeks. After several months, patients will stop taking ART, and their HIV viral load will be closely monitored to determine if the same curative effect is seen in humans. An experimental vaccine against Middle East Respiratory Syndrome (MERS) has successfully combatted the virus in mouse models and offers new insights into the design of subunit vaccines. Vaccines prompt the immune system to develop antibodies that recognize and attack a specific pathogen. Different proteins on the surface of a virus can elicit the production of distinct antibodies that vary in their ability to mobilize a robust immune response. Rather than using the entire virus, subunit vaccines contain specific proteins found on the surface of the virus. Consequently, scientists are able to include only the proteins that elicit the strongest immune response. However, this approach exposes the immune system to certain parts of the virus (i.e., the underside of these surface proteins) that wouldn’t normally be visible, and this can distract the immune system, prompting it to produce ineffective antibodies. In developing a subunit vaccine against MERS, researchers at New York Blood Center overcame this challenge by masking the spot on the vaccine that was distracting the immune system. The slightly tweaked vaccine has proved to be much more effective in protecting mice from MERS. Not only does this finding offer promise for the MERS vaccine, but this technique could be used to increase the efficacy of other subunit vaccines.

Researchers at Massachusetts Institute of Technology and Harvard Medical School have designed a star-shaped pill that releases medicines over the course of two weeks. The long-acting pill has six arms that can be folded into a capsule. Once the capsule reaches the stomach, its outer layer is dissolved, causing the six arms to pop out. Due to its size, the expanded pill is able to remain in the stomach until its arms detach and are digested one by one. The research team used the antimalarial ivermectin to test this delivery system in pigs. The medicine was continually released for two weeks—an impressive feat as oral medicines rarely last longer than a day. Long-acting medicines can significantly improve adherence to complicated treatment regimens. The researchers are now using the platform to develop drugs for neuropsychiatric disorders, HIV and AIDS, diabetes, and epilepsy. Someday soon, one drop of blood and a USB stick could be all that’s required to determine a patient’s HIV viral load. The system uses an electronic chip to detect the virus and transform it into an electronic signal, which is then picked up by the USB, enabling users to access their results off by computer. The device was used to evaluate nearly 1,000 blood samples and proved to be accurate 95 percent of the time, providing results in 21 minutes on average. Current techniques to assess viral load take three days. Patients in remote areas often have to wait much longer because their samples must be transported to laboratories. The HIV virus can develop resistance to antiretroviral treatment, resulting in increasing levels of the virus in the blood. Patients could use this tool to regularly monitor their viral load, ensuring early detection of resistance. During infection, bacteria deploy minute molecules—siderophores—to steal iron from human cells. Microbes need iron to reproduce and interfering with this process could debilitate bacteria, preventing infection. Scientists have sought to develop vaccines that train the immune system to respond to the presence of siderophores; however, the molecules are too small to prompt an adequate immune response. Now, two independent groups of researchers have demonstrated that attaching siderophores to large proteins boosts the immune response. One team used siderophores from the strain of E. coli that causes urinary tract infections, while the other used the strain of Salmonella that causes food poisoning. Both teams vaccinated mice and then exposed them to the bacteria several weeks later. While neither vaccine provided complete protection, infections were much less severe in vaccinated mice. Mice that were vaccinated against E. coli had one-tenth the bacterial load in their urine and kidneys and less inflammation in their kidneys and bladders. The Salmonella-based vaccine triggered the production of antibodies against the siderophores, resulting in a bacterial load 20,000-fold fewer in vaccinated mice.

Researchers at the US National Institutes of Health (NIH) have developed a test that can rapidly screen chemical compounds for their ability to treat drug-resistant infections. The team at NIH has already put the test to use, evaluating approved medicines, promising compounds, and drug combinations against common drug-resistant bacteria. After screening an estimated 4,000 drugs and compounds, the researchers identified 25 that effectively killed drug-resistant Klebsiella pneumoniae in the lab, including not only antibiotics, but also antifungals, antivirals, antiseptics, and even anticancer medicines. The test has also revealed three drug cocktails—each comprised of three different medicines—that can effectively treat ten common multidrug-resistant bacteria. These findings will enable clinicians to prescribe drug combinations with near certainty that they will treat a drug-resistant infection without waiting on lab results. While the tool is not yet commercialized, it can be mobilized to rapidly respond to emerging drug-resistant infections. A new study has revealed that during the 2014–2015 Ebola outbreak in West Africa, the virus evolved, enhancing its ability to infect humans. Previously, Ebola was thought by many scientists to be relatively static; however, researchers at the University of Massachusetts Medical School and University of Nottingham have independently identified a mutation in the Ebola genome—A82V—that appeared during the outbreak and could have made the virus two to four times more virulent. The mutation affects the cells on the surface of the virus that are responsible for infiltrating a host’s cells. For viral cells, shape matters, as it enables them to latch onto host cells like a key in a lock. The researchers suspect that A82V adjusts the shape of these surface proteins, allowing them to better fit into human cells. The mutation also enhances the virus’ ability to infect the cells of chimps and monkeys, while hampering its ability to infect bats, dogs, cats, rats, and mice. The team also discovered that patients with the new, mutated strain of Ebola were 27 percent more likely to die. Further research is needed to confirm this finding. Last week, the NIH and the Walter Reed Army Institute of Research (WRAIR) initiated clinical trials of an experimental Zika vaccine—the first of five phase 1 trials evaluating the vaccine. The vaccine platform was first used by WRAIR in developing a vaccine against Japanese encephalitis, a fellow flavivirus. The Zika Purified Inactivated Virus (ZPIV) contains complete, inactivated virus particles that will not cause disease but train the immune system to recognize and mount a robust response to the Zika virus. In preclinical trials, the vaccine candidate successfully induced an immune response and protected animals against the virus. The five phase 1 clinical trials will test the vaccine compared to placebos in different doses and schedules, as well as in different populations, including individuals previously exposed to flaviviruses (including Zika, yellow fever, dengue, Japanese encephalitis, and West Nile) and dengue, individuals who have received yellow fever or Japanese encephalitis vaccines, and those who have received the NIH’s experimental DNA-based Zika vaccine.