there are a few diseases out there as
grisly as Ebola but how exactly does it
bola work where did it come from
why are its outbreaks so difficult to
contain and is there any hope of getting
rid of it once and for all there's no
question about it
Ebola is terrifying with the potential
to kill within a week and a death rate
that's been as high as 90% the specter
of this violent disease is still very
much at large in the Democratic Republic
of the Congo it's time to move from a
purely reactive strategy when there's an
outbreak we also need to think of
primary prevention
I'm Peter Piot and I'm the director of
the London School of Hygiene and
Tropical Medicine I was part of the team
that isolated the Ebola virus for the
first time it may surprise you that
there are not one but two exciting
experimental vaccines and used in the
DRC and more in the works but before we
get to these promising breakthroughs we
have to dive into the surprising place
Ebola may have gotten its start fruit
bats the virus is actually an accidental
virus for us humans because it's a virus
that lives happily in some butts when
that virus crosses the species barrier
then the mortality is extremely high
there's a couple different patterns that
occur one is that someone hunts an
animal that is infected with the virus
and they catch it because they're
exposed to the blood or body fluids or
they're preparing the food that was
caught hi my name is John masazi
I am a pediatric infectious disease
specialist at the National Institute of
Health vaccine research center I've been
working on Ebola since 2005 the family
of viruses Ebola is part of is the Fila
virus family which in a Latin means
string-like viruses they are long and
filamentous they can be up to a micron
in late so it's quite quite big for a
virus when a person contracts Ebola
typically through contact with the blood
or other bodily fluids of an infected
person the virus begins to wreak havoc
in every area of their body but at first
it may not present any signs at all
there's the hot zone and outbreak
version of Ebola which
tends to be very dramatized and the
reality is that that is the the least
common presentation for Ebola so the
very thing about four stages in
infection the first is an incubation
period where you've been exposed to the
virus but you haven't yet shown signs or
symptoms of illness and that can last
anywhere from four to 21 days the second
stage of the disease progresses with
symptoms like fever and muscle aches
making it difficult to distinguish from
other flu-like illnesses the tell-tale
signs of Ebola don't typically appear
until the third stage about three to six
days after these symptoms begin people
start having fluid losses like diarrhea
and vomiting one of the classic things
is a rash that you can see on their body
and that's one of the clues that you can
get that perhaps this is a hemorrhagic
fever or Ebola virus this happens
because Ebola infects dendritic cells
and macrophages overloading the immune
system like a lightning storm frying an
electrical grid you just have an overall
what we call a cytokine storm basically
your immune cells release signals that
turn on inflammation and so you have a
giant inflammatory response cells will
put out a flag that says hey I'm
infected come and you know kill me and
Ebola stops both the signal from being
sent as well as the signal from being
received the virus can hide in places in
the body that are difficult to reach by
antibodies and that is in the I flew it
it's in the testes and also probably in
the brain the virus can also affect the
liver the adrenal gland and the
gastrointestinal tract but it's most
dangerous invasion is into the
endothelial cells that line the blood
vessels the net reaction to that is that
we would that's in your blood leaks out
into the tissues your body basically is
dehydrated in the blood vessels and so
when that happens we call it shock in
patients die of hypovolemic shock
and that progression can happen in a
matter of days the final stage of the
disease is its most severe when patients
have lost dangerous amount of blood and
fluids into their tissues and experience
a huge range of symptoms depending on
which organs the virus has reached you
are fortunate enough to survive you have
a recovery phase as well well some
patients do make it to that phase pass
of the current outbreak only 66 percent
will survive but now owing to some
promising trials in eastern Congo
experts are excited about two new drug
therapies that could potentially reduce
ebolas mortality rate by as much as two
thirds one is monoclonal antibody ma B
114 a single antibody isolated from a
survivor of an outbreak in the 1990s and
another one is Regeneron B 3
that's a you know therapeutic that also
was shown to to be effective but
treatment is only half the battle
Ebola outbreaks have become
progressively harder to contain as they
approach urban areas and due to its
disproportionate effect on health care
workers the ripple effects of the
disease have been devastating this makes
finding preventative measures a key
priority to achieve that two
experimental vaccines are currently in
use in the DRC based on their success in
previous outbreaks and Phase two
clinical trials the first one is the
life attenuated vaccine the vesicular
stomatitis virus r vs v that vaccine has
now been used well over 250,000 people
in DRC when you give it to the contacts
of someone with Ebola the protection was
close to home it deserves that vaccine
known as r vs v z Bob or vivo was shown
in field tests to be 97.5% protective
against Ebola a second vaccine is
produced by Johnson & Johnson and that
is a vaccine made of two doses one is a
killed
I don't know 26 virus and that has the
Ebola antigen and with a second
injection of an MVA
vaccine that contains multiple antigens
various Ebola strains and also Marburg
and that's just one of a handful of
experimental vaccines and various trial
phases the Erb Evo vaccine recently
approved by both US and European
governments is currently being used in
what's known as a ring vaccination
strategy essentially vaccinating
everyone who may have come into contact
with an Ebola patient ring vaccination
was used to eradicate smallpox and later
along with strong Public Health efforts
helped to finally get the 2014 to 2016
outbreak in West Africa under control
alongside the Johnson and Johnson
vaccine which is being used in a
targeted Geographic vaccination strategy
to protect villages or regions at risk
these vaccines are proving remarkably
effective in the DRC and along its
borders and will be the go-to methods as
we apply what we've learned so far to
similar outbreaks in the future
governments came together in formed
large equal what treatment units to be
able to handle the patients that were
coming in and try various treatment
regimens so that we could try to
determine what might be more optimal
care but whether developing protections
or advancing cures the keys to
containing future outbreaks lie in
cooperation preparation and putting
resources in the hands of local
communities when I look at the future of
Ebola is the first thing is that we need
much better preparedness and that means
investing in the vulnerable completes
better laboratory infrastructure regular
surveillance of suspect cases and also
possibility for deployment make sure
that the vaccines are licensed and are
available and accessible and affordable
when you deal with epidemics time is a
essence and for me it's a lesson also
that if we invest in the science if we
invest in the development for this
epidemic diseases we can do it