Johnson & Johnson Inc. (JNJ) has started clinical trials of its experimental Ebola vaccine, which uses a booster from Denmark’s Bavarian Nordic, making it the third such shot to enter human testing.
The initiation of the Phase I study in the U.K., which had been expected about now, marks further progress in the race to develop a vaccine against a disease that has killed more than 8,000 people in West Africa since last year.
Two other experimental vaccines, one from GlaxoSmithKline (GSK) and a rival from NewLink and Merck & Co. Inc. (MRK), are already in clinical development. However, the J&J vaccine offers a different approach, since it involves two separate injections.
J&J said Tuesday it had produced enough vaccine to treat more than 400,000 people, which could be used in large-scale clinical trials by April 2015, and a total of 2 million courses would be available through the end of 2015.
Previously, J&J expected more than 1 million courses this year. It also now predicts it can make enough vaccine for 5 million treatments, if required, over a 12- to 18-month period.
Just how much Ebola vaccine will be needed depends on how quickly the epidemic in Liberia, Sierra Leone and Guinea is brought under control and declines. Currently, experts project demand at anywhere between 100,000 and 12 million doses.
“As long as there are still Ebola patients, there is the risk that it will continue to go around the region,” Paul Stoffels, J&J’s chief scientific officer, told reporters.
The initial stage of first-in-human testing with J&J’s vaccine is being conducted by experts at Oxford University, where 72 healthy volunteers will get different regimens combining the vaccine components or placebo.
Additional clinical studies are planned in the U.S. later this month and soon after in east Africa, where volunteers will receive the vaccine in Kenya, Uganda and Tanzania.
In all, some 300 subjects will be involved in Phase I testing, after which J&J hopes to move rapidly into larger studies, with final-stage Phase III trials planned for the second quarter.
The J&J and Bavarian vaccine uses a so-called “prime-boost” approach of giving a first shot to stimulate the immune system, followed by a second booster a few weeks later.
The GSK and NewLink vaccines have been tested initially as single shots, although there is growing debate as to whether two-stage vaccination might be a more strategic option, since it is likely to provide better protection. The downside of the two-stage approach is that it would make mass immunisation more complicated.
“What we are doing with prime-boost is going for maximal protection, as well as long-term protection,” Stoffels said.
Importantly, tests have shown the J&J vaccine can be stored in a normal fridge for several months, rather than needing special freezing, which is difficult in rural Africa.