WHO experts flesh out Ebola vaccine plans

A World Health Organization (WHO) expert group met this week to map out the quickest way to get an Ebola virus disease (EVD) vaccine into West Africa's epidemic response arsenal, focusing on two experimental vaccines that already have clinical-grade vials ready for human trials.

The panel also explored ways to speed up clinical trials and methods to overcome hurdles in rolling out the vaccine.

Meanwhile, in West Africa's outbreak region the illness total climbed to 7,178, while the number of deaths grew to 3,338, the WHO said today in a separate report.

Ebola vaccine game plan takes shape

The 70-member group met Sep 29 and Sep 30 and included virologists, drug regulators, medical ethicists, public health officials, clinical researchers, and members of the pharmaceutical industry. Many were from West Africa's outbreak region, according to a recap of the meeting that the WHO posted today.

Three strong themes that carried through the meeting were allowing nothing to delay the vaccine work, making sure the products are safe and effective, and solidarity with the people of West Africa, the WHO said.

The two most promising candidates so far are the ones that have clinical-grade material available for phase 1 clinical trials, some of which are already under way: a chimpanzee-derived adenovirus vector vaccine developed by GSK and the US National Institute of Allergy and Infectious Diseases (NIAID) and an attenuated vesicular stomatitis virus vaccine developed by the Public Health Agency of Canada and being licensed by NewLink Genetics, based in Ames, Iowa.

Both companies are boosting their manufacturing capacity, with the goal of very significantly scaling up production during the first half of 2015.

Experts eye challenges

Experts singled out some of the practical issues that need to be worked during Ebola trials, including keeping the vaccine at the proper temperature, identifying staff to conduct the trials along international standards, and resources to scale the studies up quickly.

Though individually randomized trials would be ideal, when not feasible, alternative designs should be considered, such as cluster randomized or stepped-wedged designed, they said.

The WHO said the latter type of study sparked a lot of interest and discussion. Lessons learned from one part of the study population could be used to guide the next step of the study. The WHO said another advantage of that approach is that the vaccine can be rolled out and evaluated for efficacy at the same time.

The group discussed the best use for experimental vaccine doses already donated by Canada and suggested that in the short term they should be deployed to consenting frontline health workers.

Real-time data sharing will be a crucial part of coordinating the research and ramping up production of the vaccines that appear most promising, the WHO said, while acknowledging the long lead time usually needed to launch a vaccine. "Even under the best conditions and with the massive efforts of many partners, a significant number of doses will not be available until late in the first quarter of 2015," it said.

African participants and other experts highlighted the need to consider special issues in the outbreak region, including people who are generally distrustful of Western medicine and a broader definition of healthcare workers, which can include burial teams, hospital cleaners, and traditional healers.

The group mapped out a list of milestones, starting with preparing a mechanism for evaluation and sharing data on clinical trials in October to approving and starting phase 2 studies in January and February of 2015.

In related news, University of Minnesota infectious disease expert Michael Osterholm, PhD, MPH, wrote in a Politico editorial yesterday that the world is not preparing for the strong possibility of EVD breaking out of the three outbreak countries of Guinea, Liberia, and Sierra Leone into other African nations.

He said that, to adequately prepare, the global public health community should aim toward producing 500 million doses of Ebola vaccine as soon as possible to cover all of West Africa and possibly beyond. Osterholm is director of the Center for Infectious Disease Research and Policy, publisher of CIDRAP News.

Deterioration continues in Liberia, Sierra Leone

The WHO also released a new update on case numbers and response activities today, reporting that the number of confirmed and suspected cases as of Sep 28 has risen to 7,178 and that the number of deaths is at 3,338. The totals reflect an increase of 625 infections and 255 fatalities since the WHO's last report on Sep 26.

It warned that the numbers likely underestimate the true burden of the disease on the three main outbreak countries.

Overall, the trend shows that the number of newly reported cases have fallen, but the WHO added the caveat that reports from people on the ground suggest that the situation is still deteriorating in Liberia, especially in Monrovia, and in Sierra Leone with the number of cases underreported, especially for certain locations. The situation in Guinea appears to be more stable, but the WHO said even there the disease is still a grave concern, because the status could change quickly.

In Liberia, transmission persists in Gueckedou, which has been one of the main hot spots since early in the outbreak. The number of cases in the capital Conakry increased slightly last week, and Beyla district, which borders Ivory Coast, has now reported its first case. The country reported a large number of new suspected cases over the past week, with a large portion likely to be true EVD cases, according to the WHO.

Sierra Leone has seen an increase in cases over each of the past 6 weeks, with a surge in districts adjacent to the capital Freetown prompting quarantine. However, the hot spots Kailahun and Kenemea reported very low numbers of new cases for 2 weeks in a row, and the WHO said more investigation is need to determine if the fall is real or a result of underreporting, of which the latter which appears to be more likely, it said.

Response markers

In response developments, a new referral center opened in Liberia's Sinoe district, with the site for another one identified for Grand Kru district, an area in the southern part of the country that recently reported its first confirmed EVD cases, the WHO said in its report.

In Sierra Leone, health officials opened three isolation centers in Bombali district. Two US Navy mobile labs have arrived in Liberia and will be deployed to Bong County and Montserrado, near Monrovia. And a Chinese mobile lab team in Freetown started testing samples on Sep 29.

No other Ebola treatment units opened this week; Liberia's treatment bed shortfall is 1,500, and Sierra Leone's is 450, the agency said.

The WHO said it will convene a meeting on Oct 6 and 7 to discuss development of new guidelines for use of personal protective equipment for controlling healthcare-related infections.

A social mobilization project in Guinea reached 71,000 households, distributing hygiene kits and flyers. Workers also opened a dialogue with people in some households in Nzerekore that had been resistant to mobilization efforts and was the scene of a clash between residents and response teams.

Editorial Director Jim Wappes contributed to this report.

See also:

Oct 1 WHO statement on Ebola vaccines

Oct 1 Ebola roadmap situation report

Sep 30 Osterholm editorial in Politico

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