December 10, 2017

Research Roundup: Environmental threat of AMR, obstacles with the dengue vaccine, and an Army-developed Zika candidate

Program Assistant
PATH/Rocky Prajapati
In this regular feature on Breakthroughs, we highlight some of the most interesting reads in global health research from the past week.

The release of antibiotics into the environment is a significant environmental threat, according to a new United Nations Environment Programme report. The presence of antibiotics have been found in soil deposits, lake and river sediment, and wastewater facilities around the world, suggesting industrial, human, and pharmaceutical disposal leads to traceable amounts of antibiotic compounds in the environment. This issue alarms experts because even minimal traces of antibiotics may lead to the continued evolution of antimicrobial resistant bacteria. While more research is needed on the consequences of antibiotics in the environment, experts suggest various strategies to help mitigate the problem including deploying improved methods to treat wastewater, treating animal waste before using it as fertilizer, and improving antimicrobial stewardship.

An Army-developed Zika vaccine candidate (ZPIV) performed well across three Phase 1 clinical trials, according to new findings published in The Lancet. The three studies were designed to elicit information on background immunity, vaccine dosage, and vaccine schedule in adult populations. A total of 67 participants received two injections four weeks apart, and researchers found more than 90 percent of participants who received the ZPIV vaccine had an immune response to the virus. The Army developed the vaccine candidate in response to the 2015 outbreak, noting the need for a Zika vaccine not only to advance global health, but also to protect US service members and their families.

Countries are restricting use of the world’s only dengue vaccine—Dengvaxia— following an announcement by developer Sanofi Pasteur raising safety concerns. The company discovered, from data analysis, that the vaccine could raise the risk of a deadly form of dengue for people who had not been exposed to the virus prior to vaccination. In response, the Philippines ceased an ongoing, mass immunization campaign, and Brazil tightened restrictions on the vaccine. While Sanofi stressed there were no reported deaths related to the dengue vaccine, they believe more severe cases of dengue may occur if an immunized individual, who was not previously infected before receiving the vaccine, is then subsequently infected with dengue. This rare complication leaves children at a higher risk of contracting the severe form of dengue, as they are less likely to have been exposed to infection before receiving the vaccine. Dengue sickens hundreds of millions of people and kills more than 20,000 every year, underscoring the need for a safe, effective, vaccine.