Breakthroughs Blog: Zika

The last few years have highlighted more than ever the incredible power of vaccines—from the millions of lives saved by the unprecedented rapid development of COVID-19 vaccines to the approvals and early-stage rollout of the first-ever vaccines for malaria and chikungunya.  We are now fortunate to have vaccines to prevent more than 20 life-threatening diseases, and immunization currently prevents 3.5 to 5 million deaths every year. While it is vital that countries continue to strengthen routine immunization programs to reach the 20 million children who missed out on one or more of their vaccines in 2022, it is also important that countries sustain strong investments in research and development to deliver the next generation of breakthrough vaccines.In recognition of World Immunization Week 2024, GHTC is highlighting five vaccines in development that could be game changers for some of world’s most threatening diseases, reminding us not only of the tremendous impact vaccines have already had but also of the great promise of innovative vaccines to save even more lives in the future.1. TBIn 2022, 1.3 million people worldwide died from tuberculosis (TB), which is the second leading infectious disease killer after COVID-19. Currently, the only approved vaccine for TB is the bacille Calmette-Guérin, or BCG, vaccine, which was developed more than 100 years ago. Though effective at preventing some types of TB in infants, it offers inconsistent protection in adults and adolescents against pulmonary TB, which is why new vaccine options are urgently needed.Last month, the Bill & Melinda Gates Medical Research Institute announced the launch of a pivotal Phase 3 trial evaluating a novel vaccine for TB, which researchers hope could become the second licensed vaccine for TB. The adjuvanted subunit vaccine M72/AS01E vaccine was originally developed by GSK, along with Aeras and IAVI. The trial, which is supported by the Bill & Melinda Gates Foundation and the Wellcome Trust, is testing the vaccine’s ability to prevent latent TB from progressing to active pulmonary TB in adults and adolescents. While it is expected that the trial could take at least five years, if successful, it could lead to an urgently needed new tool with the potential to transform TB control globally.2. ZikaZika is a mosquito-borne virus that can cause congenital malformations in infants born to individuals infected during pregnancy, as well as preterm birth and miscarriage. There are currently no vaccines available to prevent or treat Zika, nor are there specific treatments.There have been numerous outbreaks of Zika around the world, with a widespread outbreak in the Americas just under a decade ago sparking the World Health Organization (WHO) to declare a Public Health Emergency of International Concern in 2016.Last month, Valneva announced the launch of a Phase 1 clinical trial to investigate the safety and immunogenicity of a vaccine against the Zika virus. The second-generation adjuvanted inactivated vaccine candidate, VLA1601, will be tested in 150 adult participants in the United States, with the first topline data from the trial expected as soon as early next year. Additionally, Moderna is advancing an mRNA-based Zika vaccine, mRNA-1893, which is currently in a Phase 2 trial in the United States and Puerto Rico; the trial is expected to end in July 2024.3. Lassa feverLassa fever is an acute viral hemorrhagic illness that is endemic primarily in parts of the West African region. Annually, there are around 5,000 deaths from Lassa fever and an estimated 100,000 to 300,000 cases. There are currently no approved vaccines that protect against Lassa fever.This month, the first participants were vaccinated in a Phase 2 clinical trial of a vaccine candidate for Lassa fever virus, which is being led by an international collaboration between IAVI, the Coalition for Epidemic Preparedness Innovations (CEPI), and in-country partners in Nigeria. The hope is that this trial, which is the most advanced Lassa vaccine trial to date, will lead to the availability of a vaccine candidate for evaluation and use in future Lassa outbreaks and, eventually, an approved vaccine for routine immunization.  4. Nipah virusNipah virus is a zoonotic virus that can cause a wide range of illnesses, from asymptomatic infection to severe respiratory illness and, sometimes, fatal brain inflammation. Nipah has an estimated case fatality rate of 40 to 75 percent, with South Asia facing the greatest burden of outbreaks. There are currently no specific drugs or vaccines for Nipah virus infection.The first human trial of a new vaccine against the deadly Nipah virus began in January of this year after the work, which started in 2017, was paused during the COVID-19 pandemic. The new vaccine, ChAdOx1 NipahB, which was developed using the same viral vector vaccine technology as the University of Oxford and AstraZeneca’s COVID-19 vaccine, will be evaluated over the next 18 months in a Phase 1 trial led by the Oxford Vaccine Group and funded by CEPI.5. ETECEnterotoxigenic Escherichia coli (ETEC) is one of the leading causes of moderate and severe diarrhea in children worldwide. It is estimated that ETEC causes about 220 million diarrhea episodes globally each year, resulting in an estimated 42,000 child deaths. There are currently no approved vaccines for ETEC, and bacterial resistance to the antibiotics often used to treat it is growing globally, underscoring the need for a preventative vaccine.ETVAC is an oral vaccine candidate for ETEC developed by Scandinavian BioPharma, which is being advanced in two different formulations, one for travel use, adults, and older children and a second “self-contained” solution requiring no mixing, which is designed for ease of administration in children under five in low- and middle-income countries. The vaccine has shown promising results in both populations in Phase 1 and 2 trials, which received partial funding from PATH through the Bill & Melinda Gates Foundation, and a Phase 2b trial was implemented among nearly 5,000 children in The Gambia, with efficacy results expected later this year, alongside the potential launch of a planned Phase 3 study in Zambia. If successfully advanced and approved, an ETEC vaccine could be a powerful new tool in our arsenal to reduce suffering and death from diarrheal disease and slow the emergence of antimicrobial resistance.  Breakthrough technologies like these vaccine candidates are possible because of long-term, consistent investment throughout the R&D process, from early-stage product development to implementation and rollout. With these promising technologies and more on the horizon, it is critical that we sustain investment in R&D to push these exciting new tools over the finish line and ensure everyone everywhere can access them. Learn more about global efforts for World Immunization Week to recognize the lifesaving power of vaccines here. 

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. Last Tuesday, Valneva announced the launch of a Phase 1 clinical trial to investigate the safety and immunogenicity of a vaccine against the Zika virus, for which there are currently no available preventable vaccines or treatments. The second-generation adjuvanted inactivated vaccine candidate, VLA1601, will be tested in 150 adult participants in the United States, with the first topline data from the trial expected as soon as early next year.  Numerous outbreaks of Zika have occurred around the world, but the virus is currently circulating in Mexico, Central and South America, the Caribbean region, and some areas of the continental United States.Moderna’s next-generation mRNA vaccine for COVID-19 elicited a higher immune response against most strains of omicron BA.4/BA.5 and the original virus than the company’s currently licensed vaccine and has a similar safety profile in Phase 3 trial. The vaccine candidate, mRNA-1283, demonstrated the highest benefits in patients over 65, who are at risk of more severe disease. The trial included over 11,000 patients from across the United States, the United Kingdom, and Canada. These results also point to the future promise of the company’s combination mRNA vaccines for COVID-19 and influenza, which are also currently in development and previously demonstrated a similar immune response to the company’s vaccines for COVID-19.The US Food and Drug Administration (FDA) recently announced the approval of Roche’s Cobas malaria test for screening blood, organ, and tissue donors, which could help reduce the risk of transfusion-transmitted malaria. The test is designed to qualitatively detect in whole-blood samples Plasmodium DNA and RNA from the five main species of Plasmodium parasite species known to cause human infection: P. falciparum, P. malariae, P. vivax, P. ovale, and P. knowlesi. Roche’s technology is now the first FDA-licensed test for screening blood donors for malaria.

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. Pfizer and BioNTech last week reported promising early-phase data on an mRNA combination vaccine against COVID-19 and influenza and announced plans to start a phase 3 trial of the vaccine, following Moderna’s similar announcement for its combination vaccine earlier this month. Moderna’s trial began last week, with Pfizer and BioNTech’s likely to start in the coming months as well. A combination vaccine for COVID-19 and influenza has the potential to greatly reduce the burden of these respiratory viruses on patients, providers, and health care systems, underscoring why these companies and the broader research community have placed a greater focus on combination vaccines coming out of the pandemic.At the annual meeting of the American Society of Tropical Medicine and Hygiene (ASTMH) last week, the World Health Organization reported the results of a major evaluation of a pilot rollout in three African countries of RTS,S, the first approved malaria vaccine, showing positive findings about the lives it has already saved. RTS,S cut deaths among young children by 13 percent over nearly four years and cut cases of severe malaria by 22 percent among kids young enough to have received a three-shot regimen. The RTS,S vaccine is notably not a perfect tool, given the limited durability of its protection and lower efficacy, but health experts say this data makes a strong case for broader rollout of RTS,S and the potential of integrating the second approved malaria vaccine, R21, into multipronged efforts to fight malaria.A research team at the Johns Hopkins Bloomberg School of Public Health has shown for the first time that human volunteers can be safely and effectively infected with Zika virus, which could benefit research efforts to gain a greater understanding of the disease and to develop vaccines and treatments to use against it, as none currently exist. This controlled human infection model is useful for research because during the 2015-2016 outbreak, researchers were unable to test experimental products in time before the epidemic subsided, and since, there have not been any large outbreaks. The new model is controversial but has been ruled by US regulators and the World Health Organization as safe and scientifically important.

In recognition of World Mosquito Day on August 20, 2023, GHTC is testing our readers’ knowledge of mosquito-borne diseases and ongoing efforts to develop treatments, vaccines, vector-control innovations, and other tools to outsmart the world's deadliest animal. Test your knowledge by taking the quiz below!