By Mick Krever, CNN

Ebola is spreading as such a rate that it is outrunning all efforts to contain it, Roy Anderson, professor of infectious disease epidemiology and former chief scientist at the British Ministry of Defence, told CNN’s Christiane Amanpour on Thursday.

“Those hospitals [in West Africa] have got to be able to deal with and quarantine a very large number of patients,” he said. “So what’s feared is that the doubling time of this epidemic is going to escape the Western response at present.”

“I’m not totally convinced that these hospitals will actually slow the spread significantly.”

Because there is neither a drug to treat infected patients nor a vaccine to protect potential ones, the only option medical workers have right now to prevent the spread are efforts to quarantine people who are infected.

“Although they may slow the spread, and we need more resources to do that, longer term the solutions must be either immunotherapy, which is putting serum into infected patients, but most importantly of course in the longer term, a vaccine.”

He said that phase one human trials of potential vaccines, in the United States, United Kingdom, and Mali, have so far presented no safety concerns. Volunteers in Oxford were given a trial vaccine last month.

“So then if that continues to be good news, then the question is an international agency and regulatory authority one – it is how can we speed up the process of getting this trial vaccine, first of all manufactured on a scale, and that’s a challenge, real challenge, for the companies, and then deploy it as quickly as possible.”

Even under “the most optimistic scenario,” though, such a vaccine would not be available until the beginning or middle of 2015.

Some have suggested that reaction in the Western world to the outbreak has been out of proportion to the threat, and that attention should really be paid to Liberia, Sierra Leone, and Guinea, where medical resources are sparse.

Dr. Kent Brantly, an American who contracted and survived Ebola, told CNN’s Anderson Cooper that the fear in America is “irrational,” because the only people who have been infected in the U.S. are health care workers who were treating an Ebola patient.

Anderson agreed that the fear may be a bit much, but did not shut the door on the idea of Ebola spreading in the Western world.

“The epidemic is spreading in Liberia, Sierra Leone, Guinea at a rate which is each primary case of infection generates two secondary cases. That’s the average. In the United States, two secondary cases generated, admittedly by health care workers who were caring for the very ill patient.”

The chief of the American military, General Martin Dempsey, caused controversy this week when he suggested that the virus could mutate and become even more pernicious.

“This virus is a little bit different from the viruses that were causing sporadic epidemics way back in 2004 and the previous forty years,” Anderson said. “The number of changes in a code, which has nineteen thousand bits, is about three hundred. Relatively small.”

“So my first concern is not mutation; my first concern is getting this under control. And at the moment there is no evidence to say this is airborne droplet transmitted.”

“However, I stress that this is a very difficult infection to study, and there’s no evidence to say not. But my assumption, and the evidence at the moment, points to contact.”