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. According to a report released last week by the Access to Medicines Foundation, just five companies are carrying out 63 percent of the urgently needed research and development projects for priority health areas such as HIV and AIDS, tuberculosis, Chagas disease, and leishmaniasis. This reliance on a small group of companies contributes to a fragile ecosystem, according to the report authors. A change in strategy for any of the companies could put access to medicines in low- and middle-income countries (LMICs) at risk. The Access to Medicines index, an independent report released every two years, ranks the world’s 20 largest pharmaceutical companies based on their efforts to make their medicines available in LMICs. This year, GlaxoSmithKline—the developer of a single-dose drug to prevent malaria relapse—tops the list of companies in the overall ranking.  Recruitment of women in Uganda has begun for a phase 3 clinical trial, which will assess if a long-acting injectable antiretroviral called Cabotegravir, administered every two months, is safe and effective as a form of Pre-Exposure Prophylaxis (PrEP) to reduce an individual’s risk of contracting HIV when exposed to the virus. This recruitment is part of a large-scale, five-year trial that will be conducted in six additional countries—including Kenya, Malawi, Botswana, Zimbabwe, South Africa, and Swaziland—among approximately 3,200 HIV-negative individuals who are at a high risk of contracting the virus. If Cabotegravir proves to be safe and efficacious, it would offer a new alternative for individuals on PrEP other than taking daily oral pills. A vaccine to prevent Zika virus infection was found to be safe and induce an immune response in an early stage trial, according to an announcement released on November 19 from developer Emergent BioSolutions Inc. and partner Valneva SE. The vaccine, VLA1601, was tested in two doses in 67 adult trial participants. The initial results contained analyses up to day 56, after the first vaccination. Final analysis will take place up to day 208 and is expected to be released in the first quarter of 2019. Emergent BioSolutions Inc. announced an exclusive worldwide licensing deal for Valneva SE’s Zika vaccine in July of last year.

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. After hitting its primary goal in a phase 2 trial, Themis may be one step closer to developing a vaccine to protect against chikungunya—a disease which causes debilitating joint pain and for which there is currently no treatments or vaccines. MV-CHIK, Themis’ chikungunya vaccine candidate, was tested at two dose levels in a total of 263 participants and was found to induce neutralizing antibodies against the disease in all groups after two injections. Themis reported seroconversion rates ranging from 86 to 100 percent, touting the vaccine candidate as “promising and potentially effective” against the disease. Themis is looking to move the vaccine candidate into a phase 3 study “in the near term” and will likely pursue a priority review voucher, as the US Food and Drug Administration recently added chikungunya to its list of eligible diseases.  A new study suggests that frontline health workers in the Democratic Republic of Congo who received experimental Ebola vaccines could be protected against the virus for longer than a year. The study, which tracked healthy volunteers in the United Kingdom who received vaccines against Ebola between 2014-2016—including Merck’s rVSV-ZEBOV, GlaxoSmithKline’s ChAd3 EBOV, and Janssen’s AdHu26—found that after two-and-a-half years, those vaccinated still have a strong antibody response to the virus. These findings provide insight into how the vaccines can be used in future outbreaks in the region and how health care workers could be vaccinated before the disease becomes widespread during an outbreak. Researchers now plan to give a booster dose to the study participants to determine how it adds to their immunity. By utilizing the same technology used to develop the Ebola vaccine—a technology known as viral vectors—researchers also believe they can speed the development of vaccines for other infectious diseases. Researchers at the University of Southern California believe they have identified a panel of biomarkers specifically associated with symptomatic Zika infection during pregnancy—a discovery which could lead to the development of new prenatal screening tests to detect fetal abnormalities caused by the virus, as well as a better understanding of how Zika causes these abnormalities. During the study, researchers examined the immune systems of pregnant women through blood samples—comparing the samples of 30 Zika-infected pregnant women in Brazil to 30 healthy pregnant women in Brazil and 14 in Los Angeles. The researchers specifically examined cytokines, messenger chemicals released by the body in response to an infection, and identified 16 cytokines associated with abnormal births from Zika. However, it is unclear if the cytokines cause the birth abnormalities or are released in response to another cause.

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.