As New Ebola Cases Wane, It’s Full Steam Ahead on Vaccines

The good news on Ebola continues, for now.

The number of people in West Africa falling victim to the virus has dropped to its lowest level in months, according to the World Health Organization. Only eight cases of Ebola were reported in Liberia last week, compared with more than 200-per-week in September. Guinea reported 20 new cases. With 117 new cases last week, Sierra Leone remains the worst affected country. But even that number is down several-fold from just a few months ago.

Community engagement, education and better protective practices have helped to slow the disease. Rapid diagnostics are emerging so that future Ebola cases can be detected and treated more quickly. But these tactics alone are unlikely to eradicate Ebola.

U.S. and international public health officials are taking advantage of the current lull in the Ebola epidemic to focus on pushing vaccine development into the field.

Two vaccine trials in Liberia are slated to kick off in mid-to-late February.

A late-stage trial of both Ebola vaccines with 27,000 participants may begin in Liberia within the next few weeks and may last up to a year.  The Phase 2 and 3 trials of both vaccines will be done in tandem, and both will be tested versus placebo.

The first vaccine, developed by Glaxo Smith Kline and the NIH (National Institutes of Health), is a chimp Type 3 adenovirus that contains segments of Ebola virus genetic material from 2 virus species, Sudan and Zaire. It does not contain Ebola virus itself.

The second vaccine, developed by New Links Genetics and the NIH, is a VSV (Vesicular Stomatitis Vaccines) carrying Ebola material.  Like the GSK-NIH vaccine, it showed some promising Phase I data.

Clinical trials will include those at highest risk including healthcare workers, burial teams, household members of the family where an individual has been or is likely to have contracted Ebola.

Perhaps the only downside to a waning Ebola epidemic is that more participants are needed to make the vaccine trials statistically robust.  In addition to the Liberia trials, officials are planning a trial in Sierra Leone.  In late January, NIH and CDC officials said that trial may need to be expanded beyond the original plan for 6,000 participants if Ebola rates continue to decline in the country.

In the meantime, there is currently no drug available shown to be safe and effective for treating Ebola. NIH is currently looking at drugs repurposed for Ebola as possible therapies.

Thomas Geisbert, an Ebola expert at the University of Texas Medical Branch in Galveston, has pointed to two drugs in short supply — ZMapp and TKM-Ebola – as promising potential treatments for Ebola based on their effectiveness in treating monkeys infected with the disease.

The ZMapp treatment (Mapp Biopharmaceuticals) will be tested in Liberia on approximately 150 people. TKM-Ebola (Tekmira Pharmaceuticals) could also be effective for curing the disease.

While there are high hopes for these vaccines and therapies, West Africa is by no means out of the woods.  Declining international interest/funds and the upcoming rainy season could hamper efforts to control the disease.

The NIH, CDC and FDA have put commendable efforts behind Ebola therapies, diagnostics and vaccines in the past year. Despite the criticism over the U.S. handling of its own Ebola patients, the government appears to be on the right track. Hopefully these efforts will lead us on a path to eradicating the disease once and for all.


Ipsita Smolinski is Managing Director for Capitol Street, a healthcare research and consulting firm in Washington, DC

Morning Consult