US CDC in talks with Nigeria over human trial of Ebola vaccine

US CDC in talks with Nigeria over human trial of Ebola vaccine

Alexander Chiejina with wire reports

Officials from the Centers for Disease Control and Prevention are also in talks with health officials in Nigeria about the prospects for conducting a Phase 1 safety study of the vaccine among healthy adults in the country amid mounting anxiety about the spread of the deadly Ebola Virus Disease (EVD) in West Africa, according to the National Institutes of Health (NIH).

The pace of human safety testing for experimental Ebola vaccines has been expedited in response to the ongoing Ebola virus outbreak in West Africa which has impacted negatively on businesses in the three affected countries –Liberia, Sierra Leone and Guinea, with neighbouring countries closing their borders and banning flights from affected countries to other parts of Africa.

NIH explained that “The early-stage trial will begin initial human testing of a vaccine co-developed by NIAID [National Institute of Allergy and Infectious Diseases] and GlaxoSmithKline (GSK) and will evaluate the experimental vaccine’s safety and ability to generate an immune system response in healthy adults. Testing will take place at the NIH Clinical Center in Bethesda, Maryland, USA.”

The experimental vaccine is expected to first be given to three healthy human volunteers to see if they suffer any adverse effects. If deemed safe, it will then be given to another small group of volunteers, aged 18 to 50, to see if it produces a strong immune response to the virus. All will be monitored closely for side effects.

It is understood that the vaccine will be administered to volunteers by an injection in the deltoid muscle of their arm, first in a lower dose, then later in a higher dose after the safety of the vaccine has been determined.

Anthony Fauci, NIAID Director, explained that there is an urgent need for a protective Ebola vaccine, as it is important to establish that a vaccine is safe and spurs the immune system to react in a way necessary to protect against infection.

“We know the best way to prevent the spread of Ebola infection is through public health measures, including good infection control practices, isolation, contact tracing, quarantine, and provision of personal protective equipment. However, a vaccine will ultimately be an important tool in the prevention effort. The launch of Phase 1 Ebola vaccine studies is the first step in a long process.”

Efforts to reach the minister of Health Onyebuchi to confirm this development via telephone at the time of filing the report proved abortive. When BusinessDay reached Dan Nwomeh, special assistant to the Minister of Health on Media and Communication to confirm this, he said “I have no information on that for now”

In the meantime, Fauci said that trials cannot currently be done in the four countries affected by the recent outbreak -- Guinea, Sierra Leone, Liberia and Nigeria -- because the existing health care infrastructure wouldn't support them.

Some of the preclinical studies that are normally done on these types of vaccines were waived by the Food and Drug Administration, (FDA), USA  during the expedited review, Fauci said, so "we want to take extra special care that we go slowly with the dosing."

The vaccine did extremely well in earlier trials with chimpanzees, Fauci said. He noted that the method being used to prompt an immune response to Ebola cannot cause a healthy individual to become infected with the virus.

Funding from an international consortium formed to fight Ebola will enable GlaxoSmithKline to begin manufacturing up to 10,000 additional doses of the vaccine while clinical trials are ongoing, the pharmaceutical company said in a statement. These doses would be made available if the World Health Organization decides to allow emergency immunizations in high-risk communities.

The GSK/NIAID vaccine is one of two leading candidate vaccines. The other was developed by the Public Health Agency of Canada and licensed this month to NewLink Genetics, a company based in Iowa. Earlier this month, the Canadian government shipped what it said was ‘800 to 1,000’ doses of that vaccine to Liberia, at the government's request. It is however not clear whether it has been given to health workers or anyone else there.

While there currently is no proven treatment for Ebola beyond supportive care, government agencies and small biotech firms have been scrambling to speed up development of several potential therapies and vaccines.

A third vaccine, also developed by the NIH, was recently tested in primates and found to protect them from infection; it was given in combination with Depovax, an adjuvant that has been used with other vaccines and cancer therapies to boost the body's immune response.

While vaccines might be given to prevent infection among health workers or other people thought to be at high risk, development has also been speeded up on drugs that might potentially be given to patients who already have the disease.

The drug that's received the most attention is ZMapp, which has been given to at least seven individuals in the current outbreak, including two American missionary medical workers, Nancy Writebol and Kent Brantly.

Earlier versions of ZMapp, which received backing from the U.S. and Canadian governments as well as from biotech firms, have shown some ability to protect rhesus macaque monkeys more than two days after they were infected with the virus.

The vaccine going into trials this week is based on an adenovirus -- a type of cold virus -- that's found in chimpanzees. The virus delivers genetic material derived from two species of Ebola virus, including the Zaire strain that's responsible for the current outbreak. Those genes are meant to trigger the development of antibodies in the person who receives the vaccine, antibodies that can specifically defend against Ebola.