Scientists race to test vaccines for Uganda’s Ebola outbreak

A multipronged international effort has begun to pull out all the stops to launch trials of experimental Ebola vaccines in Uganda. Uganda has had 18 confirmed and 18 suspected cases of the disease, including 23 deaths, which is a high case fatality rate. A vaccine candidate that is farthest along in development could be ready for a trial by the end of the month.

There are proven vaccines for the disease, which has led to a dozen outbreaks in the Democratic Republic of the Congo, and was responsible for the huge outbreak of the disease in West Africa. The outbreak in Uganda is being driven by a distant viral cousin known as Sudan ebolaviruses, which last caused an outbreak in Uganda in 2012. Nancy Sullivan, head of biodefense research at the National Institute of Allergy and Infectious Diseases, says that the Sudan ebolaviruses are different from the other ones. In 2016 Science published a survey of 50 leading vaccine researchers who ranked the Sudan ebolaviruses vaccine as the top priority based on feasibility and need. The vaccinemakers didn't have much incentive to make one. Producing enough doses fast enough will be a challenge even if the trial goes well.

There are three experimental vaccines that have been tested in human studies but have not had a real world test. Ana Maria Henao-Restrepo is a WHO vaccine specialist who is coordinating discussions between the Ugandan government and stakeholders elsewhere in the world.

Glaxosmithkline donated the license for the candidate it began to develop during the West African outbreak to a vaccine institute. The vaccine contains a shuttle that can deliver the vaccine into cells. The candidate has worked well in monkey studies and small-scale clinical trials and was awarded a $128 million contract by the U.S. government.

According to Henao-Restrepo, WHO organized two rounds of consultations this week with vaccine developers and others, which resulted in a unanimous agreement that the Sabin candidate should be first in line for a Uganda trial. The draft proposal is being evaluated by health officials. The study could start before the end of October if everything goes well.

According to Richard Koup, acting director of the vaccine research center, NIAID has 100 doses of the vaccine and is giving them to Uganda. There are tens of thousands of doses that need to be put in small quantities. The Coalition for Epidemic Preparedness Innovations (CEPI), a nonprofit that supports R&D for vaccines, is trying to find a manufacturer who can do what's called "fill and finish."

The current outbreak shows how difficult it is to make and deploy experimental vaccines that can stop an outbreak. There are many gaps that need to be plugged. It shows that the world isn't ready to be clear about who is responsible for responding to a deadly outbreak. If a vaccine is shown to work, countries may once again be waiting in line for it, like they were for COVID-19 shots. She says that it's not clear who is responsible for manufacturing additional doses. It is crazy that we are in this situation now. Governments and philanthropies should fund the manufacture of the most promising candidates when there is an outbreak.

There is a second candidate. The University of Oxford has 71 doses of its experimental single-shot vaccine, which is meant to protect against both the Sudan and Zaire Viruses. A variation of the widely used COVID-19 vaccine has yet to be proven in a monkey study. The Serum Institute of India has been contracted by Oxford to make 20,000 more doses.

The European Commission approved a vaccine made by Johnson & Johnson in July 2020, but it requires two doses to be effective. The company has a lot of vaccine It was shown in monkey studies to be protective and in human trials to be safe and stimulating. There are at least three vaccine candidates that are at an early stage of development.

The World Health Organization has proposed a trial in Uganda that will use the same strategy as the one that proved the worth of a vaccine in a study in West Africa. The vaccine was given to contacts of known cases instead of being tested in the general population. The researchers did not compare the vaccine with a placebo shot, but gave some participants the vaccine immediately, whereas others were waiting.

Epidemics have come to an end without vaccines due to strict hygiene and personal protective equipment. Over the past 4 years, the Democratic Republic of the Congo has used a number of vaccines against the ebola virus. She says that vaccines make it easier to find contacts of cases. Contacts have been hard to identify in the Uganda outbreak. People who get the vaccine soon after an illness are less likely to spread the disease.

Sullivan is leaving NIAID to become director of the National Emerging Infectious Diseases Laboratories at Boston University. She says that there is more that needs to be done to be prepared for a Pandemic.