U.S.
and Canadian researchers might have finally discovered a vaccine against one of
the world’s deadliest disease caused by the Ebola virus.
Ebola usually begins suddenly with symptoms such as fever,
headache, sore throat, weakness, joint muscle aches, diarrhea, vomiting and
stomach pain. Symptoms may also include a rash, red eyes and bleeding. Ebola hemorrhagic
fever has 90 percent mortality and, so far, there have been more than 1,500
cases in humans.
Dr. Anthony Sanchez of the Centers for Disease Control and
Prevention in Atlanta
said one of the candidate vaccines is about to be tested on people for the
first time.
"The biothreat posed by Ebola virus cannot be overlooked. We are seeing
more and more naturally occurring human outbreaks of this deadly disease. With
worldwide air travel and tourism, the virus can now be transported to and from
remote regions of the world. And it has huge potential as a possible weapon of
bioterrorism. We desperately need a protective vaccine," Dr. Anthony
Sanchez, of the U.S. Centers for Disease Control and Prevention, said in a
prepared statement, the Washington Post reports.
The vaccine, developed by Canadian scientists last year, has been tested in
three types of animals. The trial showed the vaccine kept at least half from
dying when it was administered after infection. Four of eight primates injected with a lethal dose of Ebola virus
survived when they were given the vaccine within 30 minutes of exposure.
“Ebola virus infection of humans can be highly lethal but monkeys rarely
survive the infection and have been very useful as animal models. Ebola vaccine
trials using nonhuman primates have provided unambiguous results and have
allowed the development of protective vaccines to progress rapidly. Successful
human trials will mean that we can vaccinate healthcare workers and other key
personnel during outbreaks of Ebola hemorrhagic fever, helping us to protect
their lives and control the spread of the disease,” said Dr. Sanchez.
Ebola virus is very dangerous and producing and testing a vaccine is
extremely challenging for the scientists, as there are only a very limited
number of high containment facilities with staff capable and authorized to
conduct the research.
“Ebola virus is a Biosafety Level 4 threat, along with many other hemorrhagic
fever viruses. As well as the difficulty in getting the right staff and
facilities, vaccines for viruses like Ebola, Marburg and Lassa fever have been difficult
to produce because simple 'killed' viruses that just trigger an antibody
response from the blood are not effective. For these viruses we need to get a
cell-mediated response, which involves our bodies producing killer T-cells
before immunity is strong enough to prevent or clear an infection,” Dr. Sanchez
said.
Dr. Sanchez presented an overview of the Ebola vaccine’s development on
Monday at the Society for General Microbiology’s meeting in Edinburgh, Scotland.
