|Ebolavirus under an electron microscope--Courtesy of CDC|
Positive results from the Phase I trial of yet another experimental Ebola vaccine are in, but unlike other vaccines in the field, this one is based on the virus strain that caused the 2014 epidemic, not an older one.
The candidate--a recombinant adenovirus type-5 vaccine developed by Beijing Institute of Biotechnology and Tianjin CanSino Biotechnology--was tested in a double-blind, placebo-controlled trial in Jiangsu Province, China, on 120 healthy adults. 40 patients received a low dose and 40 received a high dose, with 95% of the former group showing a positive immune response, and all 40 of the latter group exhibiting a response. Those who received the high dose also made more antibodies than the low-dose group.
However, the study doesn't show whether the immune response is strong enough to fight off an actual Ebola infection. In the abstract, researchers called for further clinical trials in Africa. However, the number of Ebola cases in West Africa is dwindling, and researchers may run out of Ebola-infected patients on whom to test their vaccines. They also suggested that a "prime-boost" combination could induce "broader or more durable immunity."
Johnson & Johnson ($JNJ) and GlaxoSmithKline ($GSK) are already looking into fortifying the immune response from an Ebola vaccine with a booster shot. Glaxo is testing its shot with Emergent BioSolutions' ($EBS) candidate as a booster in a trial at the University of Oxford. Meanwhile, J&J announced that it would start trialing its own two-dose Ebola regimen in Africa.
Maryland-based Novavax ($NVAX) is also developing a vaccine based on the 2014 Ebolavirus strain, and in February, it laid out plans for Phase I clinical trials in Australia. Those results are not expected until mid-2015.
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