Uganda continues to grapple with an outbreak of Ebola. The most clinically relevant strains of Ebola are Ebola Zaire and Ebola Sudan. Uganda’s current outbreak is caused by the Ebola Sudan strain, a strain different from that which caused the 2014 epidemic in West Africa.
Both the Sudan and Zaire strains of Ebola were first recognized in the mid-1970s with two independent outbreaks one in Nzara and Maridi in Sudan and another in Yambuko, Zaire (Democratic Republic of Congo). The initial person-to-person spread in both cases led to further hospital-based spread that led to significant spread in villages surrounding the hospitals. Both of those outbreaks were characterized by hemorrhagic fever and had high mortality. Both viruses looked very similar to Marburg virus but were serologically different.
Early studies with Ebola Sudan and Ebola Zaire from patient derived isolates suggested that Ebola Zaire was more lethal than Ebola Sudan. The Zaire strains were easier to isolate and grow in culture and needed lower titers to be lethal in mice and monkeys. The Sudan strains were harder to isolate, grow in culture, better tolerated with higher monkey survival rates compared with Zaire stains. Early studies of both strains suggested that there was no cross protection across the strains.
Much of these earlier studies were conducted outside of Africa. Primary isolates from acutely infected individuals or convalescent serum following the outbreaks in Sudan and Zaire in the 1970s were packaged and shipped to research laboratories in the west, providing western scientist access to the isolates for further research. This was important for advancing science but the lack of significant scientific research capacity on the continent meant that African scientists were not at the forefront of characterizing the biology of the virus. As a consequence development of diagnostics and therapeutics was done outside of Africa. African government funding and investment in science is minimal such that western resources are required to fund most of the studies, field work, and laboratories. Bureaucratic roadblocks and insufficient investments in research infrastructure by local governments make Africa not competitive for research, collaboration and locally driven innovation.
When the West Africa Ebola outbreak occurred in 2014, rapid advancements were made in therapeutics for Ebola. These included small molecule antivirals such as Remdesivir and biologics such as REGN-EB3 (a cocktail of three neutralizing monoclonal antibodies targeting the Ebola Zaire surface glycoprotein) and Ansuvimab (mAb114) an antibody isolated from an Ebola survivor. The outbreak taught us the importance of supportive care, and fluid and electrolyte maintenance. All of which can be very challenging in African settings where even crystalloid fluids may need to be imported. Among the first recipients of the advances in therapeutics and case management were western clinicians who became infected while serving in West Africa. Many were airlifted to their countries of origin where they received outstanding care with survival rates of over 80%. African healthcare settings are often unable to adequately respond to outbreaks and provide the level of care required. As we face Ebola Sudan as a continent the question is how do we not repeat the errors of the past? What will African scientific leadership look like in the response to Ebola Sudan?
There are two approved vaccines for Ebola Zaire. Small molecules such as Remdesivir may have activity against the Sudan strain and will need to be tested. It is likely that new monoclonal antibodies may need to be developed for the Sudan strain. Vaccines have helped control recent Ebola Zaire outbreaks in DRC but may not work for this Uganda outbreak. The J&J prime and boost vaccine theoretically may be helpful as the prime provides immunity to Ebola Zaire while the boost is designed to target other Ebola species including Ebola Sudan. The second boost is given 8 weeks after the first making its utility in an acute response difficult to assess. In addition efficacy against the Sudan strain has not been established. New vaccines may be needed. With many countries on the continent independent for over 40 years, it should be local African universities, independent research institutions or biotech companies taking the lead. But with under resourced academic centers and an absent biotech industry, leadership in immunogen design through to clinical development is being undertaken by western academic and pharmaceutical partners.
There are several reasons that many can cite for Africa failing to respond to its own crises, and many of them are valid and true. The leadership needed to establish a development agenda that ensures strong science education, infrastructure and builds a biotechnology industry is lacking. Where are the leaders like Li Kwoh-ting referred to as the “Father of Taiwan’s Economic Miracle” on the continent? Among his many achievements was to create an enabling environment for local talent to thrive in the absence of interference. This eventually led to the establishment of globally competitive Universities in the young nation, the development of technology industries that are now global leaders in the manufacture of semiconductors and other materials while also attracting its highly skilled diaspora to return. We hope that the silver lining from these multiple regional and global pandemics over the last few years, is to awaken African continental leadership out of complacency to make the appropriate investments in science and technology. The return on investment will be high with a healthier and more prosperous continent. Our vision should be that in a few decades African reliance on western innovation should have reversed with western nations purchasing the latest monkeypox antivirals from Africa or buying therapeutics for returning travelers with drug resistant malaria from an African manufacturer, or new monoclonal antibodies for the few Ebola cases it may see in returning travelers from an African start up pharmaceutical company. This must be the collective vision on the continent and can be achieved.
We are all interconnected particularly when it comes to infectious diseases. All infections globally are only one bus ride or plane ride away. It is important that we collectively respond. It is also equally important that we hold leadership accountable for not only responding now but planning for future threats. By no means do we imply that only Africa should solve its technology deficit problems, it should be a global effort but African political leadership should not be a hinderance but a key facilitator. In pandemic and epidemic preparedness, we are all only as strong as the weakest link.
*A. Tariro Makadzange is the author of this blog. She is an infectious disease physician and viral immunologist focused on tackling healthcare programs in Africa.
*Nyasha Elose contributed editorial assistance.