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By Ben Hirschler
LONDON, July 31 (Reuters) - Scientists and drug companieswill continue to research the potential of alternative Ebolavaccines, despite a shot from Merck and NewLink Genetics proving 100 percent effective in a trial in Guinea.
Experts said on Friday different kinds of vaccines wereneeded that might be better suited for different populationgroups.
Because Merck's VSV-ZEBOV is a live, or replicating,vaccine, there were initial worries about its safety. In theevent, it proved about as safe as a flu vaccine, said Universityof Reading virologist Ben Neuman, but it was still not given tochildren or pregnant women.
Replicating vaccines have the advantage of requiring onlyone dose, making them suitable for emergency use. Butnon-replicating vaccines, which may need two injections, couldbe longer-lasting and better suited to protecting people outsidean epidemic.
"There is a place for all of these different modes and it'simportant that development work on other vaccines continues,"Rebecca Grais, director of research at Medecins Sans Frontieres(MSF) Epicentre, told Reuters.
"It's also important to have multiple manufacturers in orderto ensure competition."
MSF was one of the organisations behind the successfulclinical trial with Merck's vaccine, which the World HealthOrganization said had brought the world to the verge of beingable to protect humans against Ebola.
GlaxoSmithKline applauded its rival's success butsaid it would persevere with development of its alternativenon-live vaccine.
"We believe that it is important that the internationalcommunity continues to support the development of more than onevaccine for the control of Ebola including those that might bemore suitable for vaccination of pregnant women, infant childrenand the immunocompromised," it said in a statement.
GSK hopes also hopes to test its vaccine in Guinea, althoughWHO vaccine expert Marie Paule Kieny said this might not bepossible, given the dwindling number of Ebola cases.
Johnson & Johnson, which is developing atwo-injection vaccine in partnership with Bavarian Nordic, said it remained committed to the programme and hopedto start a trial in Sierra Leone in the coming weeks.
A number of other groups are at an earlier stage ofresearch, including a team from the University of Texas workingon an inhaled vaccine.
Adrian Hill, director of the Jenner Institute at theUniversity of Oxford, said the success of Merck's vaccinesuggested other products in mid-stage trials should also proveeffective.
Although these alternatives may not be tested during thecurrent epidemic, they could still be licensed and readied foruse in future outbreaks based on human immune response resultsand data from non-human primate experiments. (Additional reporting by Tom Miles in Geneva; Editing by ElaineHardcastle)
