Breakthroughs Blog: Zika

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. The World Health Organization (WHO) and UNICEF have reported nearly 1 in 10 children did not receive any immunizations in 2016. This includes immunizations for diphtheria-tetanus-pertussis (DTP). WHO and UNICEF reported that the global immunization rate for the full round of the DTP vaccine is only 86 percent, falling short of the 90 percent goal of global immunization. Furthermore, in 2016, eight countries had DTP immunization rates of less than 50 percent. Estimates by WHO and UNICEF suggest that 10 million more children in 64 countries need to be vaccinated every year in order to achieve the 90 percent goal. This highlights the need to bring vaccines to low-resource settings that have been chronically affected by low immunization rates. A new study published in Proceedings of the National Academy of Sciences highlights a new diagnostic tool that performed well in distinguishing Zika from other flaviviruses, including dengue. UC Berkeley and Humabs BioMed partnered to create a low-cost, easy-to-use diagnostic tool to specifically test for the Zika virus. Researchers found this tool was capable of distinguishing between Zika and other flaviviruses, as well as distinguishing current and past Zika infections in patients. The tool had 91.8 percent sensitivity—the ability to correctly identify those with the disease—and 95.9 percent specificity—the ability to correctly identify those without the disease. This tool could be used in Zika- and dengue-endemic areas, assisting in diagnostic processes and subsequent treatment, especially among populations adversely affected by Zika, like pregnant women. For the first time in history, more than half of all HIV-infected individuals are receiving treatment. In 2016, it was estimated that 19.5 million individuals were receiving HIV treatment, with a total of 36.7 million people infected with HIV. These estimates are both increases from the estimated 17.1 million treated and 36.1 infected in 2015. Further, AIDS-related deaths have decreased by more than half since 2005. Though these rates are promising in the fight against the global epidemic, the United Nations (UN) acknowledges that there is much left to do in the fight against HIV and AIDS, particularly in the context of less stable health systems in resource poor settings.  

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. A recent Congressional hearing on Zika has revealed that there is a lack of consensus regarding the diagnosis and treatment of the virus. Furthermore, only approximately 25 percent of babies born from women who have been exposed to Zika receive the necessary follow-up to evaluate their children for developmental defects. Such follow-up is critical—Zika can cause defects in the infant months after birth. As a result, the impact of Zika may be underestimated, leaving public health professionals uneasy about proposed budget cuts by the Trump Administration, which could exacerbate the treatment and reporting challenges that characterize the current outbreak. Chagas disease, colloquially known as "kissing bug disease," is more deadly than previously thought due to underreporting of the disease. Going undiagnosed while carrying Chagas can elevate the risk of death, primarily due to associated heart problems that will develop over time. Chagas disease initially mimics symptoms of the flu, often causing a misdiagnosis and lack of proper treatment, and it can lie symptomatically dormant for years, silently causing irreparable damage to the heart. There is currently no effective vaccine against the disease. The Democratic Republic of Congo’s (DRC) Ministry of Health has approved the use of an experimental Ebola vaccine to combat the outbreak. The vaccine, though experimental, proved to be highly effective in clinical trials. Details of how the vaccine will be deployed have not been announced yet, but if further cases are confirmed, it will likely be given to contacts and contacts of contacts of those with a confirmed case. So far, there have only been two confirmed cases, but over fifty suspected cases.

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. Researchers in Brazil have discovered the structure of the protein responsible for replicating the Zika virus thousands of times in cells, causing the virus to break through the cell wall and infect the body. Through many months of collecting data and studying the origins of the virus, the researchers put together a three-dimensional model of the protein and published their findings in Nature Communications. Zika is a flavivirus and in the same genus as diseases like yellow fever, dengue, and hepatitis C. Because of the genetic similarity, researchers and scientists have found that sofosbovir, a commonly used drug to treat hepatitis C, is a good therapeutic option for those suffering from Zika. The unlocking of Zika’s genetic code will lead to the development of new solutions to the virus. It recently became global news that RTS,S (trade name Mosquirix™), the candidate malaria vaccine furthest along in development, is beginning vaccine pilot programs in three chosen countries: Ghana, Kenya, and Malawi. The vaccine, created through a partnership with PATH’s Malaria Vaccine Initiative and GlaxoSmithKline, is given in four doses over a specific period of time. It is not yet known if tracking of these vaccine doses will be 100 percent. Any vaccine administered in multiple doses, whether for malaria or HPV, requires a lot more work in educating individuals about the need to return for all treatments necessary to ensure the vaccine’s success. UNICEF and members of the vaccine community will work with government authorities to ensure the supply chain delivers vaccines to children in need. If successful, the burden of malaria could decrease drastically. While this vaccine is promising to many individuals in these three countries, the search for a more perfect vaccine is high on the priority list for health researchers around the globe. In order to increase global access to immunization, successful and smooth-moving supply chains are necessary. The problem? Immunization supply chains are complex and every part of the chain needs to be working perfectly to ensure access to the vaccines. Many members of the immunization community have neglected the supply chain facet of vaccine delivery, and as a result, these supply chains have suffered and grown obsolete. With these chains being out-of-date, many children remain unvaccinated from even the most common diseases. A special issue published in Vaccine highlights these issues and brings the need for supply chain renewal to the forefront of the conversation. But even after this publication, more has to be done to ensure all members of the vaccine community work together to guarantee access to vaccines is in reach for all. Despite vaccine initiatives being stronger than ever, there is still a glaring gap in the number of children receiving basic vaccines. Currently, there are over 19 million children who are unvaccinated, leaving them susceptible to diseases that can be protected against. The American Academy of Pediatrics and the Centers for Disease Control worked together to establish the Global Vaccine Action Plan (GVAP) aimed at closing the gap of vaccine inequality around the globe. GVAP has already seen many successes, including fostering a working relationship with government institutions to implement surveillance techniques to figure out what vaccines children need most in each country. Kenya and Nepal, for example, have initiatives through pediatricians to educate families about the importance of vaccines for children’s development and longevity of life. GVAP is in the forefront of bridging the gap of health inequity and bringing immunization to all.

In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week. Nearly three-fourths of new and emerging human diseases are zoonoses, animal diseases that spillover into humans. Now, scientists are reporting “spillback” of human diseases into monkey populations in South America, as Zika virus becomes endemic and as Brazil faces its worst yellow fever outbreak in years. Human strains of Zika have been found in black-striped capuchin monkeys and marmosets, a concerning trend as these species could become a reservoir for the virus. Capuchins are often kept as pets, employed as street entertainers, or hunted as meat, and these routine interactions could lead to future human outbreaks. Meanwhile, Brazil’s yellow fever outbreak has killed nearly 70 people and more than 600 monkeys, threatening rare and endangered species in the Atlantic rainforest. Researchers at the University of Southampton have designed miniscule 3D spheres that can simulate conditions inside the human body, an exciting development that could help scientists better understand how pathogens interact with human cells. The researchers created one such sphere with a collagen matrix, similar to the makeup of human lungs, to study antibiotics that target and kill the tuberculosis bacterium. The 3D spheres can be used four times longer than existing 2D systems, enabling researchers to monitor the progression of infections over time. Colistin is often the last line of treatment for multidrug-resistant infections, however, its use as a growth promoter for livestock in China has led to the development of colistin-resistant bacteria on chicken farms. While colistin resistance was first reported in China in 2015, it has now spread to 25 countries across four continents. Scientists have discovered a specific gene (mrc-1) that confers resistance to colistin and that can be easily spread between bacteria. Now, a new study has revealed that mrc-1 is much more prevalent than previously believed. The gene was found in nearly all bacteria collected from chicken farms in China, even though only half of the samples proved resistance to colistin. The findings also suggest that flies may be accelerating the spread of colistin resistance by transporting resistant bacteria from farms to surrounding communities. A cocktail of three bacteria-killing viruses could provide rapid protection against cholera, filling a critical need during outbreaks, as vaccines do not provide protection until approximately two weeks after administration. The technique is known as phage therapy as it utilizes bacteriophages—viruses that target and kill specific bacteria. While phage therapy has been around for nearly a century, it was largely eclipsed by the advent of antibiotics, but has gained increasing attention in recent years in response to the growing threat of antimicrobial resistance. To develop the regimen, researchers at Tufts University School of Medicine first identified phages that target the cholera bacterium, and then narrowed their focus to those that can survive and function in the human small intestine, where cholera infection takes place. Animal studies suggest that the cocktail could prevent infection when taken just three hours prior to exposure. The research team has established an independent company, PhagePro, and plans to further test and develop the therapy.