The first human trial of a prime-boost Ebola vaccine regimen from Johnson & Johnson has launched in the United Kingdom, bringing the number of vaccines against the virus that are now in clinical trials to three.

In a statement today, the company said the trial is being conducted by a team from the Oxford Vaccine Group in the University of Oxford’s Department of Pediatrics. It said the first volunteers have received their first doses, and researchers expect to complete enrollment by the end of January.

Study will gauge safety, dosing

The vaccine, in development at Johnson & Johnson’s Janssen Pharmaceutical Companies, uses a combination of two components based on AdVac technology from Crucell Holland BV, a Janssen subsidiary, and MVA-BN technology from Bavarian Nordic.

Preclinical studies of a prime-boost regimen using the two components by researchers at the National Institutes of Health (NIH) found that, when given 2 months apart, the vaccine completely protected nonhuman primates against death from the Kikwit Zaire strain of the virus.

Trials of a monovalent version of the vaccine targeting the Zaire strain responsible for West Africa’s Ebola outbreak are part of a program to develop a multivalent vaccine.

For the first phase 1 trial that’s under way, four volunteer groups will be randomized to get the active vaccine or a placebo. Those receiving the active vaccine will be immunized with one of four priming regimens on day 1 and will receive the boost component either 1 or 2 months later.

The company said the results will help researchers answer questions for the second phase of the study, such as the order the two components should be given and how closely the doses should be administered.

Oxford University said in a statement yesterday that its vaccine group plans to vaccinate 72 healthy adults by the end of January and that the volunteers are mainly from the Oxfordshire region. Matthew Snape, MD, one of investigators, said the main goal of the study is to assess the vaccine’s safety profile. Researchers will also measure the antibody and T-cell responses over 1 year, and further trials are planned for the United States and Africa early next year.

“While public health measures are currently still the best way to bring the outbreak under control, if we have a safe and effective vaccine it could begin to have an impact later this year,” he said in the statement. “That is the goal that is seeing manufacturers, public health bodies and research regulators come together to accelerate the first clinical trials of new Ebola vaccines.”

He said having at least three Ebola vaccines entering early safety trials is good news. “Having multiple vaccines progressing through clinical trials increases the likelihood of vaccine manufacturers having the capacity to meet production demands should mass immunization be required. The more vaccines and more manufacturers there are working on this, the better,” Snape said.

Phase 1 trials of two other Ebola vaccines targeting the Zaire strain launched in late 2014. One developed by the NIH and GlaxoSmithKline (ChAD3) uses a modified chimpanzee adenovirus, and one developed by Canadian researchers and licensed by NewLink Genetics and Merck uses an Ebola virus protein spliced into a vesicular stomatitis virus (VSV-EBOV).

Scaled-up production plans

Along with today’s trial launch announcement, Johnson & Johnson said it was accelerating production of the vaccine regimen though its partnership with Bavarian Nordic. It said it has produced more than 400,000 regimens for use in large-scale clinical trials by April. The company projected that 2 million two-dose regimens would be available through the end of 2015 and, if needed, manufacturers could make up to 5 million regimens within 12 to 18 months.

Janssen’s earlier goal was to make at least 1 million regimens by the end of the year, with 250,000 available for clinical trials by May.

Modeling by researchers at the London School of Hygiene and Tropical Medicine has suggested that, to bring the epidemic under control, vaccine demand ranges from 100,000 doses to protect frontline health workers to 12 million doses for a large-scale adult vaccination in the three hardest-hit countries.

Other developments

• The number of Ebola infection in the three hardest-hit countries has grown to 20,712, including 8,220 deaths, the World Health Organization (WHO) said today in its latest update. The data reflect cases reported in Guinea and Sierra Leone as of Jan 4 and in Liberia as of Jan 2. The countries have reported 56 more infections and 67 more fatalities since yesterday.
• Dismissing rumors that surfaced last week, the WHO said today that there are no suspected Ebola cases in Iraq. In a statement, the agency noted that several news outlets reported on Dec 31 a rumor of Ebola cases in Mosul, Nineveh governorate. Iraq’s Ministry of Health and the WHO investigated the report through existing surveillance networks and contacts with health authorities and officials at Ibn Sine Hospital in Mosul, the agency said. “All sources contacted have negated the existence of any suspected cases of Ebola,” the WHO stated. The agency said the laboratories in Mosul lack the capability to diagnose and confirm the Ebola virus, but it said it and the health ministry have increased surveillance efforts to ensure early detection of any Ebola cases.
• The governments of Guinea, Liberia, and Sierra Leone all recently announced plans to open schools again, which have been shuttered to curb the spread of Ebola, according to an update today from the United Nations Mission for Emergency Ebola Response (UNMEER). It said Sierra Leone’s president on Jan 1 announced the intention to restart schools soon, and similar announcements by Guinea and Liberia soon followed. Liberia’s’ target date is Feb 2, though Guinea did not set a specific date.

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