Breakthroughs Blog: Zika

Interested in more global health innovation news? Every week GHTC scours media reports worldwide to deliver essential global health R&D news and content to your inbox. Sign-up now to receive our weekly R&D News Roundup email. Two new studies at Scripps Research have shown how human and mice antibodies can bind to and stop the infection of all five types of Ebolavirus—a key step in developing therapeutics capable of neutralizing all variants of the virus. During the studies, scientists observed the ability of a human antibody called ADI-15878 to bind directly to the viral “fusion loop,” which the virus uses to fuse with human cells to initiate infection, making it impossible for the virus to enter into human cells. Discovered in a human Ebola survivor, ADI-15878 is the only known antibody ever found to neutralize all five strains of the Ebola virus. A new study shows the potential of a novel microneedle platform to be used to administer vaccines during a pandemic. Researchers created a unique prototype vaccine that combined different technologies including: tiny microneedles that penetrate only the upper of the skin, a version of the H5N1 vaccine made from noninfectious “virus-like” particles that can be rapidly produced in tobacco plants, and an ingredient called an adjuvant that speeds up and strengthens the body’s response to the vaccine and has demonstrated protection against related viruses. While the study showed the product was effective in ferrets and appeared safe in humans, large-scale human trials are still needed. As vaccine researchers search for new approaches to combat pandemics, this prototype could lead to vaccine patches that could be distributed rapidly and administered without a nurse. Scientists plan to test the efficacy of a Zika vaccine candidate by intentionally infecting people with the virus, a strategy known as a human challenge trial. Researchers first launched the vaccine trial in March 2017 following an outbreak of the virus in the Americas in 2016 and had planned to open new trial sites in infection hot spots, but the effort is currently in limbo given the significant drop off in Zika cases. A major concern of researchers is that those participating in the trial may never be exposed to the virus, making it impossible to determine if the vaccine works. Plans to conduct a human challenge trial for this Zika vaccine candidate were halted by an ethics committee in 2017, which worried that people intentionally infected with the virus might transmit it to their sexual partners. Now, this method is being considered again as cases drop and industry loses interest in bringing a vaccine to market.

Interested in more global health innovation news? Every week GHTC scours media reports worldwide to deliver essential global health R&D news and content to your inbox. Sign-up now to receive our weekly R&D News Roundup email. Clinical trials have begun for the latest vaccine candidate against the Zika virus. The trial, which will include 28 adult participants, will test the safety and immune response from the vaccine, which contains a weakened form of the virus created from the combined genetic material of different viral strains. If the vaccine candidate is found to be safe, it could be added to another vaccine candidate currently undergoing testing for effectiveness against four types of dengue—creating a single vaccine against both diseases. Both vaccine candidates were developed at the National Institute of Health’s National Institute of Allergy and Infectious Diseases. On August 10, the US Food and Drug Administration approved Annovera, the first-of-its-kind self-insertable contraceptive vaginal ring that can be used for an entire year. Annovera, developed by the Population Council, is being heralded as a revolutionary new option for low-income women as it can be used for a year without a return trip to the physician or pharmacy and does not require refrigeration. Along with the benefits it offers regarding convenience, Annovera also offers women versatility. “Annovera offers the convenience of a long-acting method like the IUD because there is no daily action needed, but the control of a short-acting method like the pill because a woman can start or stop it at any time,” said Julia Bunting, president of the Population Council. Although pricing for Annovera has not yet been made public, the Population Council is continuing its efforts to make the product available to the approximately 214 million women in low- and middle-income countries that have an unmet need for contraception. Annovera is expected to hit the market at the end of 2019 or early 2020. A new type of bednet—that combines a chemical that kills mosquitoes with another that impedes their reproduction—was found to reduce clinical malaria cases by 12 percent, compared to conventional nets, during a two-year clinical trial in Burkina Faso. The study also showed a 51 percent reduction in risk of a malaria-infective mosquito bite in areas with the combination bednets. The bednets used in the study combine a pyrethroid insecticide, which repels and kills mosquitoes, with pyriproxyfen, an insect growth regulator that shortens the lives of mosquitoes and reduces their ability to reproduce. With mosquitoes increasingly becoming resistant to the pyrethroids used in conventional nets, these bednets offer an alternative to fighting malaria in areas where mosquitoes have become resistant.

Mosquitoes: This pervasive posse of pests and the deadly diseases they carry have terrorized towns and sickened citizens for far too long. For decades, a fearless force of heroic health workers has fought to keep these bloodthirsty bugs at bay, but to finally put an end to these murderous mozzies and the dastardly diseases they distribute, they need new tools, including vaccines, drugs, diagnostics and vector-control products. For World Mosquito Day, GHTC is taking a moment to shine a spotlight on the ghastly gang of mosquito-borne diseases and the innovations we need to finish these frightening foes for good. Malaria Mal A. Ria is old, cruel, and has killed more people than all of humanity’s wars combined. Since the 1950s, countries have fought a sustained war against this nefarious nemesis. Increased global action led to the development and introduction of cheaper drugs, rapid diagnostics, and child-friendly medicines, as well as mass distribution of insecticide-treated bednets, which help drive Mal A. Ria from several countries where she formally had a foothold and weakened her forces. Yet, today progress has stalled and Mal A. Ria is fighting back hard, having developed resistance against commonly used insecticides and treatments Fortunately, scientists are fighting back too. A new generation of insecticides and vector control products is advancing through the pipeline, the first vaccine is undergoing pilot roll out in sub-Saharan Africa while other candidates progress through development; and researchers are employing cutting-edge gene editing techniques to alter Mal. A Ria’s ability to pass on her parasite. Continuing support for these efforts is critical to wipe out this formidable foe. Dengue   Also known by the aliases “Breakbone Fever” and “Dandy Fever,” Den Gue has largely operated under the radar as a member of the Neglected Tropical Disease crime syndicate, attacking as many as 400 million people annually. Den Gue often induces a painful fever, and his attacks can leave victims with long-term neurological and liver problems, or in some cases kill them. He typically attacks during the day, rendering bednets a less effective tool to fight him. Unfortunately, health workers have no specific treatment or cure to deploy against Den Gue. While there is a vaccine, it is only appropriate for use in certain circumstances and better point-of-care diagnostic tests are needed to ensure its safe administration. Ultimately, a variety of tools will be needed to vanquish this adversary, so researchers are hard at work testing other vaccine candidates and exploring whether infecting mosquitoes with a bacterium known as Wolbachia could prove to be an effective tactic. Chikungunya While he may be a lesser-known member of the Neglected Tropical Disease crime syndicate, Chiku N. Gunya is still a dangerous adversary reaching over 60 countries in Asia, Africa, Europe, and the Americas. An attack by Chiku N. Gunya can leave victims with debilitating joint pain that can sometime persist long after the attack. Unfortunately, health workers have few tools at their disposable to reign in his criminal activity: There is no vaccine, specific treatment, or cure, and current diagnostic tools are challenging to employ in remote regions. Researchers are working feverishly to deliver new tools to fight this foe. Several promising vaccine candidates are now undergoing testing in human clinical trials and researchers are exploring whether currently available antivirals could be repurposed to combat Chiku N. Gunya, as well as developing new antivirals treatments. Zika While Zi Ka has been operating since at least the 1940s in certain places in Africa and Asia, her crimes did not capture widespread public attention until she carried out a large-scale attack on the Americas from 2015-2016, leading the World Health Organization to declare a public health emergency. Her crimes are particularly cruel, as the victims she targets are pregnant women, resulting in severe birth defects in some children. When Zi Ka captured her spot on the most wanted list in 2015, health workers had few tools to stop her reign of terror and that remains the case. There is no vaccine, specific treatment, or cure, and diagnostic tests have trouble distinguishing her attacks from that of Den Gue or other mosquito-borne disease miscreants. Scientists are working to ensure the world is better prepared if she decides to undertake another major attack. While it could be many years until they are available, several vaccine candidates are currently under development, and experimental diagnostic tests have been made available on an emergency basis as researchers continue to test and refine these tools.  R&D: The key to ending these enemies While our heroic health workers have made strides in stifling these diabolical diseases and protecting the populace, these cronies still cause considerable calamity in communities worldwide. Our call to action should be clear: We need research and development (R&D) and new technologies to exact an end to these enemies for good.

Interested in more global health innovation news? Every week GHTC scours media reports worldwide to deliver essential global health R&D news and content to your inbox. Sign-up now to receive our weekly R&D News Roundup email. The Ministry of Public Health of the Democratic Republic of Congo has launched Ebola vaccinations for high-risk populations only one week after announcing the latest outbreak of the disease in the North Kivu province. Of the 44 cases reported so far, 17 have been confirmed. A total of 3,220 doses of the rVSV-ZEBOV vaccine candidate, developed by Merck, are currently available in country while additional doses have been requested. An agreement between Gavi, the Vaccine Alliance and Merck will ensure additional doses of the vaccine are available on an emergency basis as it goes through the licensing process. The World Health Organization has provided key logistical support in establishing a cold chain and sending necessary supplies for the vaccinations, aiding in the deployment of vaccine experts, and facilitating the negotiation of protocols with the manufacturer and the national authorities. Biobanks provide vital specimens and infrastructure to support scientific research and innovation. While in the developing world, biobanks are well established, issues such as unreliable internet connectivity, a lack of access to resources such as water and electricity, a lack of highly skilled and trained personnel, and the cost of setup have stifled their establishment in low- and middle-income countries (LMICs) on the African continent. Despite these barriers, LMICs in Africa should prioritize setting up biobanks, argues a group of researchers from the University of Western Cape and Stellenbosch University. They write, “Having access to rich genetic diversity across Africa would allow researchers to understand disease, develop better diagnostics and treatments, medicines and vaccines, geared toward the continent’s population.” A single-dose Zika vaccine candidate developed by researchers at The Ohio State University has proven effective in triggering an immune response in mice, according to a recent study. The vaccine uses a weakened, harmless form of the Vesicular stomatis virus—also known as foot-and-mouth diseases in cattle—to deliver proteins from the Zika virus. This method has been used with other vaccines, such as the Ebola vaccine being used in the recent outbreaks. While further testing is required to see if it is effective in humans, the vaccine candidate’s suggested ability to elicit an immune response with one dose means it has the potential to be especially valuable in hard-to-reach areas and low-resource settings.