Recombinant vesicular stomatitis virus vector vaccines for WHO blueprint priority pathogens

Fathi, Anahita; Dahlke, Christine; Addo, Marylyn M.

Emerging infectious diseases are a major threat to public health. Ebola virus (EBOV) and other high-threat pathogens have recently been declared one of the top ten health threats of 2019 by the World Health Organization (WHO). 1 Out of the five Public Health Emergencies of International Concern (PHEIC) that WHO has declared to date, four have been caused by emerging or re-emerging viruses. The last few years, humanity experienced novel and increasingly frequent outbreaks for which timely and efficient countermeasures were lacking. Between 2013 and 2016, more than 11,000 people lost their lives to the dramatic West African Ebola virus disease epidemic. In 2015, the Middle East Respiratory Syndrome coronavirus (MERS-CoV) demonstrated to the world how rapidly a virus can spread into new regions due to travel, when a 68-year-old Korean man returning from the Middle East was infected by MERS-CoV and became the index case for a chain of secondary mainly nosocomial transmissions cumulating in 138 MERS-CoV infections, including 36 deaths. 2 The 2016 Zika virus outbreak in the Americas and its resulting cluster of associated neurological disorders and neonatal malformations, 3 also was declared a PHEIC, to name just a few recent outbreaks that emphasize the urgency to create strategies to contain future outbreaks fast and effectively. In the future, socioeconomic factors including an increased global human population and lifespan, urbanization, intensified global travel and mobility and the effects of climate change will further ripen conditions for the emergence and rapid spread of viruses between and among populations. Vaccines are the most effective way to prevent and control this viral spread; however, few vaccine candidates for emerging infections exist. As a result of this phenomenon of supply vacuum, novel viral outbreaks such as the EBOV crisis found the global medical community ill-prepared, and the deployment of a preventive vaccine was delayed due to the lack of clinical-stage vaccine candidates.