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Description
The World Health Organization presents this Q&A broadcast on COVID-19 transmission with Dr Micheal Ryan, Executive Director of the WHO Health Emergencies Programme and Dr Maria Van Kerkhove, Technical lead COVID-19, WHO Health Emergencies Programme. Host is Nyka Alexander. Recorded June 9, 2020 in Geneva, Switzerland.
The City of Cupertino would like to express thanks to the World Health Organization for permission to use their video materials during COVID-19 pandemic. More information can be found at https://who.int/covid-19
For more information regarding the impact of the COVID-19 outbreak in Cupertino, please visit https://cupertino.org/coronavirus
C
Hello
and
welcome
welcome
to
another
QA
live
with
WH
o
today
we're
going
to
be
on
Facebook
on
Twitter
and
on
LinkedIn
as
well.
Yesterday,
at
our
regular
press
conference
we
talked
about
Cova
transmission
and
from
the
questions
we
got
afterwards
and
from
the
kind
of
coverage
we
can
see,
there's
a
lot
of
interest
in
the
subject.
So
we
wanted
to
give
you
a
chance
to
speak
to
our
colleagues
directly,
we'll
be
taking
questions
from
the
journalists
and
from
the
public
as
well.
C
So
my
name
is
Nick
Alexander
I'm
part
of
the
communications
team
here
at
wo
headquarters,
I'm
joined
today
by
dr.
Mike
Ryan,
he's
head
of
the
Emergencies
program
at
debauch,
oh
and
dr.
Maria,
Van,
Kirk,
Kove
who's,
the
technical
lead
for
kovat.
Thank
you
both
for
being
here
so
for
your
questions
on
Twitter
use,
hash
tag.
Ask
WH
o
those
of
you
who
follow
us
have
done
this
before
and
on
Facebook
and
LinkedIn.
C
D
There
were
quite
a
lot
of
messages
that
I
received
overnight
and
that
we
received
about
making
some
clarifications
to
some
points
that
I
made
yesterday
at
the
press
conference,
so
I
think
it's
important
just
to
just
if
I
can
briefly
cover
some
of
them.
Perhaps
some
of
the
misunderstandings
from
what
I
said
yesterday
so
I
think
what's
important
related
to
transmission
is
what
we
know.
D
Importantly,
what
we
don't
know
and
what
we're
trying
to
do
to
really
understand
this
very
complex
question.
So
what
we
do
know
about
transmission
is
that
we
know
that
people
who
are
infected
with
Kovan
19
many
develop
symptoms,
but
there
are
some
people
who
do
not,
and
so
the
majority
of
transmission
that
we
know
about
is
that
people
who
have
symptoms
transmit
the
virus
to
other
people
through
infectious
droplets.
But
there
are
a
subset
of
people
who
don't
develop
symptoms
and
to
truly
understand
how
many
people
don't
have,
since
we
don't
actually
have
that
answer.
D
I
wasn't
stating
a
policy
of
whu-oh
or
anything
like
that.
I
was
just
trying
to
articulate
what
we
know
and
in
that
I
used
the
phrase
very
rare
and
I
think
that
that's
misunderstanding
to
state
that
that
asymptomatic
transmission
globally
is
very
rare.
What
I
was
referring
to
was
a
subset
of
studies.
I
also
refer
to
some
data
that
isn't
published,
and
this
is
information
that
we
receive
from
our
member
states
through
either
presentations
that
they
give
it
member
state,
briefings
or
presentations
that
are
given
to
us
through
teleconferences.
D
As
you
know,
and
as
we've
said
previously,
we
convene
global
expert
networks
and
at
many
of
those
we
discuss
a
lot
of
ongoing
research.
Ongoing
studies
that
are
there
and
I
was
referring
to
some
detailed
investigations.
Cluster
investigations
case
contact
tracing
where
we
had
reports
from
member
states
saying
that
when
we
follow
asymptomatic
cases,
it's
very
rare
and
I
used
the
phrase
very
rare
that
we
found
a
secondary
transmission.
What
I
didn't
report
yesterday
was
because
this
is
a
major
unknown,
because
there's
so
many
unknowns
around
this
some
groups.
D
Some
modeling
groups
have
tried
to
estimate
what
is
the
proportion
of
asymptomatic
people
that
may
transmit,
and
these
are
estimates
and
there's
a
big
range
from
the
different
models,
depending
on
how
the
models
are
done
and
where
they've
done
from
which
country.
But
some
estimates
of
around
40%
of
transmission
may
be
due
to
asymptomatic.
But
those
are
from
models,
and
so
I
didn't
include
that
in
my
answer
yesterday,
but
wanted
to
make
sure
that
I
covered
that
here.
So.
C
That's
a
lot
to
unpack
it.
We
know
it's
a
the
new
disease,
we're
learning
a
lot
about
it.
A
lot
of
it
is
still
confusing,
as
we
learn
more
some
things
change
as
well,
so
we're
going
to
have
a
chance
to
get
into
that
a
little
more
deeply.
Today
off
the
top.
You
said:
there's
things
we
know
and
there's
things
we
don't
know
what
are
for
you
and
for
you
Mike
as
well.
If
you
want
to
jump
in
what
are
the
big
questions
that
we
would
still
like
to
understand
better
so.
D
For
me,
related
to
this
particular
topic
is:
what
is
the
proportion
of
the
population
that
are
truly
asymptomatic?
How
many
people
are
infected
with
kovin
19
and
really
don't
develop
symptoms?
We
know
a
number
of
them
who
are
reported,
as
asymptomatic
actually
may
have
mild
disease.
They
may
go
on
to
develop
symptoms,
but
we
don't
know
I
mean
we
don't
have
a
clear
picture
of
this
we're
six
months
into
a
pandemic,
there's
a
huge
amount
of
research
that
is
being
done,
but
we
don't
have
that
full.
We
don't
have
that
full
picture
yet.
D
C
E
Cousin,
that's
a
good
point.
Marie
makes
and
I
think
that
comes
down
to
trying
to
determine
while
is
actually
driving
transmission
at
community
level
and
what's
creating
severe
cases
that
end
up
in
hospital
end
up
in
ICU,
we
want
to
save
lives.
We
want
to
stop
people
getting
to
that
to
that
situation.
E
We've
seen
many
countries
using
that
as
a
primary
strategy
in
linked
to
other
physical,
distancing
and
other
strategies,
but
that
core
strategy
of
doing
that
and
in
in
that
sense,
for
whatever
proportion
of
the
disease,
is
transmitting
from
asymptomatic
individuals
and
that's
where
you
said
that
is
unknown
and
that
is
occurring.
I'm,
absolutely
convinced
that
that
is
occurring.
The
question
is
how
much
well
what
we
do
know
is
that
when
we
focus
on
detecting
suspect
cases,
who've
got
clinical
disease
and
we
identify
them
and
test
them,
and
we
identify
their
contacts
and
quarantine.
E
Their
contacts
that
we
can
drive
the
yarn
off
the
low
one
we
can
drive
from.
We
won't
stop
all
transmission,
but
what
we
do
is
we
suppress
transmission
and
in
the
in
the
large-scale
public
health.
The
social
measures
that
were
put
in
place,
the
so
called
lock
tones
because
many
countries
could
not
see
where
the
virus
was.
There
were
so
many
potentially
sick
people,
people
with
mild
symptoms,
potentially
people
with
no
symptoms.
The
decision
was
made
and
I
think
correctly.
E
The
decision
in
many
countries
was
to
try
and
essentially
distance
everybody
from
everybody
put
everybody
in
their
homes
for
a
period
of
time,
in
order
for
the
flames
of
the
epidemic
to
to
die
down
and
then
go
back
to
a
more
sustainable
strategy
of
opening
up,
linking
that
to
good
surveillance.
So
I
think
that's
what
we're
learning
we're
learning
is.
E
If
we
go
after
the
virus,
where
we
know
it
is-
and
we
know
that
suspect
cases
with
symptoms
can
transmit-
and
we
know
we
can
find
those
individuals,
so
we
can
isolate
those
individuals
and
we
can
identify
their
contacts.
The
real
science
challenge
now
is
to
fully
understand
what
is
the
contribution
of
purely
asymptomatic
people
to
transmission,
and
can
we
find
strategies
to
detect
those
individuals
and
also
control
the
spread
of
disease
at
that
level
and
I?
E
Think
that's
where
we're
coming
into
the
issues
of
new
types
of
testing,
faster
testing,
antigen
testing
and
being
able
to
do
larger
scale.
Population-Based
testing
the
difficulty
with
doing
that
at
population
level
at
the
moment
is
very
few
countries
have
the
capacity
to
do
that.
So
we
have
to
focus
our
testing
on
those
who
we
need
to
test
most
health
workers,
people
in
long-term
care
facilities,
people
who
are
clinically
unwell
with
the
disease,
so
I
think
there
is
much
to
be
answered
on
this.
E
I
think
that's
what
we've
recommended
as
a
comprehensive
strategy.
It's
not
do
one!
It's!
It's
do
all
of
the
things.
It's
the
it's!
The
physical
distancing,
the
personal
hygiene.
It
is
the
surveillance
and
they're
finding
of
suspect
cases,
testing,
tracing
quarantine,
isolation
and
and
shoring
up
and
strengthening
the
health
system.
So
it
doesn't
collapse
when
there
are
so
many
cases
coming
through
and
in
countries
that
have
implemented
those
measures
in
a
timely
way
and
done
it
consistently
consistently
sustainably
and
have
communicated
effectively
with
populations.
E
C
D
This
science
is
not
static.
You
know
the
evidence
is
not
static.
Our
understanding
doesn't
stay
the
same,
we're
constantly
pulling
in
all
information
from
every
source.
We
can
so.
The
sources
of
information
come
from
published
papers
papers
that
show
up
in
peer-reviewed
journals
that
have
gone
through
the
full
peer
review,
but
we
also
in
this
pandemic,
have
access
to
a
lot
of
pre
prints.
So
these
are
papers
that
are
posted
online
and
that
are
shared
with
us,
but
it's
before
they
go
through
peer
review.
D
We
have
a
lot
of
expert
network
teleconferences,
so
these
other
groups
we
bring
together
for
clinical
management
for
laboratory
and
virology
for
infection
prevention
and
control
for
risk
communication
for
modeling,
and
here
is
where
we
bring
together
hundreds
of
scientists
and
public
health
professionals
from
all
over
the
world
to
discuss
over
the
phone
regularly
many
times
per
week.
The
latest
information
we
have
on
each
topic,
our
experiences
with
patients
with
different
types
of
analyses,
with
epidemiologic
studies
or
clinical
studies
or
laboratory
studies,
experimental
studies.
D
We
also
gather
information
from
our
member
states
from
from
everyone
out
there.
You
know
how
are
you
dealing
with
this
virus?
What
are
the
interventions
you've
put
in
place?
How
is
it
working?
You
know
what
is
your
experience
and
so
that
that
is
incredibly
valuable,
because
the
practical,
hands-on
experience
from
each
country
is
really
helping
us
to
understand
this
virus
even
more,
and
then
we
have
these
specialized
networks.
You
know
we
have.
D
There
are
strategic
advisory
group,
the
stag,
so
we
have
different
specialized
groups
that
we
bring
together
and
and
those
are
through
teleconferences
as
well,
but
it's
a
constant
revision.
It's
a
constant
evolution
and
debate
and
I
mean
that
in
a
constructive
way
of
saying
again,
what
do
we
know?
You
know
what
are
the
key
questions?
What
don't
we
know
and
what
are
we
doing
to
address
those
unknowns?
It's
not
enough
to
say
we
don't
know
we
need
to.
We
need
to
actively
pursue
research
studies
to
help
us
fill
in
some
of
those
gaps.
I'll.
C
Take
your
questions
from
from
Twitter
in
a
second
and
Mike
I'll,
go
to
you
next
I
just
want
to
say
if
you're
looking.
If
you
want
to
see
where
we're
summarizing
what
we
are
saying
now
about
transmission,
you
can
look
at
the
mass
guidance
that
was
published
on
Friday.
We
did
a
lot
of
communication
around
the
masks
on
page
two
there's
a
summary
of
what
we
know
about
transmission.
It's
footnoted
summarizes
what
the
sources
are.
So
that's
a
good
place.
C
E
E
Virtually
for
treat
next
three
days
and
their
job
is
to
go
through
every
single
piece
of
information,
knowledge
and
experience
gained
and
contact
tracing
for
covert
19
over
the
last
four
months.
Their
job
is
to
challenge
each
other.
What
what's
worked,
what
hasn't?
What
is
the
kind
of
training
that's
needed?
What
is
the
kind
of
guidance?
How
would
what
is
the
best
way
to
communicate
with
communities
about
contact
tracing
which
can
often
seem
intimidating
from
outside?
So
it's
not
just
the
technology,
it's
how
you
implement
it.
E
At
the
end
of
that
three
days,
I
got
I
can
tell
you
right
now
that
what
we
think
about
contact
tracing
today
at
the
start
of
that
meeting
collectively
will
evolve
into
a
better
understanding
of
what
works
and
what
doesn't,
and
that
will
then
be
added
into
our
advice
and
our
guidance
and
passed
back
to
our
our
member
states
and
to
institutions
all
over
the
world.
So
that
could
be
a
scientific
briefing
or
scientific
advice,
but
when
it
comes
to
strategic
policy
for
strategy
for
control,
clearly,
contact
tracing
is
within
our
current
strategy.
E
So
any
advance
on
understanding
of
how
to
make
contact
tracing
more
effective,
won't
change
our
strategy,
but
it
will
change
the
emphasis
of
that
strategy
and
will
change
the
quality
and
effectiveness
and
efficiency
of
how
we
do
that
piece
of
the
strategy.
So
some
of
what
we
do
is
to
gather
evidence
to
see.
Do
we
have
the
right
policy
and
strategy?
Are
we
taking
the
right
approach
and
some
of
the
research
and
gathering
we
do
is
to
make
what
we're
already
doing
more
focused,
more
effective,
save
more
lives.
So
it's
not
everything.
E
We
do
shifts
our
policy
and
certainly
Maria
spoke
yesterday.
You
know
in
response
to
a
question
from
the
media
and
referred
to
a
great
extension,
much
of
the
material
that's
in
in
our
in
our
guidance
already,
and
that
that
certainly
wasn't
neither
Maria's
intention
or
the
intent
of
DOE
BHO
to
say
there
is
a
new
or
different
policy
there
isn't.
There
is
still
too
much
unknown
about
this
virus.
E
There
is
still
too
much
unknown
about
its
transmission
dynamics,
but
again,
what
we
do
know
is
when
we
go
to
try
and
detect
suspect
cases
who
are
clinically
unwell
and
we
test
those
and
we
trace
their
contacts
and
we
isolate
our
requirement
in
the
context
of
those
people,
and
we
do
that
diligently
and
we
do
with
that
over
a
sustained
period
of
time
we
can
avoid
large-scale
community
transmission.
We
have
seen
that
we
can
avoid
large-scale
lockdowns
in
that
situation,
or
some
countries
have
managed
to
do
that.
E
They've
taken
another
path,
but
it
has
to
be
done
with
great
consistency
and
great
persistence.
Notwithstanding
that
when
the
lock
downs
are
when
the
so
called
lactose
public
health
and
social
measures
happened,
they
put
everybody
at
home,
not
just
symptomatic
or
asymptomatic
in
pact,
because
they
stopped
all
forms
of
transmission
for
a
couple
of
weeks.
E
Now
that
people
are
coming
back
to
their
daily
lives,
we
see
those
small
spikes
and
cases,
and
we
now
have
to
determine
how
can
we
make
sure
that
those
small
spikes
new
clusters
don't
turn
into
big
ones
into
big
new
piece?
And
that's
why
we
believe
sticking
with
our
strategy
right
now
that
comprehensive
strategy
is
the
best
way
to
avoid
that.
C
So
this
is
a
Facebook
live
and
we're
on
Twitter
and
we're
on
LinkedIn,
and
the
point
is
to
take
questions
from
the
audience
as
well.
So
we
have
a
question
here
from
Tanya
Regan
who
asks
what's
the
difference
between
asymptomatic
and
pre-symptomatic
transmission
or
people
who
would
like
to
take
that
one.
D
So
this
is
a
good
question,
because
the
use
of
the
word
asymptomatic,
pre-symptomatic
symptomatic,
is
confusing
and
it's
not
always
used
consistently
by
different
groups.
So
when
we
say
asymptomatic,
we
mean
somebody
that
does
not
have
symptoms
and
does
not
go
on
to
develop
symptoms.
Truly,
no
symptoms!
That's
what
we
mean
when
we
say
this,
and
when
we
read
this
in
papers,
that's
what
we
expect
to
see
and
when
we
talk
to
people,
that's
what
we
expect
to
see.
D
But
in
fact
sometimes
when
you
go
back
and
you
talk
about
a
population
or
you
say
a
little
bit
some
not
all,
because
there
is
asymptomatic
infection,
some
have
some
mild
disease,
and
so
it
may
not.
They
may
not
quite
register
that
I'm
sick.
You
know
it's
I
just
feel
a
little
bit
unwell,
I'm
just
a
little
bit
under
the
weather,
I'm
feeling
a
little
bit
fatigued
and
some
of
those
individuals
we
would
classify
as
pre-symptomatic,
which
means
they
have
not
yet
developed
symptoms.
D
D
What
we
need
to
better
understand-
and
this
is
one
of
the
major
unknowns
is-
is
what
proportion
is
that
is
contributing
to
transmission,
and
then
we
have
symptomatic
people
so
have
people
who
have
known
symptoms
of
Kovan
and
those
symptoms
have
been
changing
over
time,
I
think
in
the
beginning,
we
focus
a
lot
on
respiratory
symptoms.
We
focused
on
fever
sore
throat,
generally
feeling
unwell,
and,
as
this
pandemic
has
evolved,
we've
learned
a
lot
more.
We've
heard
about
like
a
loss
of
taste,
a
loss
of
smell.
D
C
Many
people
have
asked
this
one.
We
talked
about
our
mask
guidance
as
well,
and
people
have
associated
it
with
the
idea
that
there's
a
lot
of
transmission
happening
from
people
who
are
asymptomatic
and
that's
why
perhaps
at
this
point
we
recommended
more
circumstances
under
which
people
should
wear
masks.
So
a
few
people
have
asked,
can
you
explain
what
Debra
chose
current
guidance
is
on
masks?
We
did
a
facebook
live
on
this
just
yesterday.
C
D
Tricky
so
yes,
we
can
so
we
published
guidance
on
Friday,
and
we
just
we've
discussed
this
at
the
presser
and
the
Facebook
our
recommendations
for
the
general
public.
What
is
new
and
that
guidance
is
that
we
recommend
the
use
of
a
fabric
mask
for
people
in
the
general
community
living
in
areas
where
there's
community,
where
there's
transmission,
where
there's
active
transmission
and
they
can't
practice
physical
distancing.
D
So
when
they're
in
crowded
situations
such
as
public
transportation,
for
example,
or
is
some
kind
of
closed
settings,
we
recommend
the
use
of
a
fabric
mask
and
part
of
that
is
because
for
source
control.
And
when
you
put
on
this
fabric
mask
and
in
the
guidance
we
actually
put
out
information
on
the
types
of
materials
that
can
be
used
to
act
as
a
barrier.
D
So
if
you
yourself
are
infected-
and
you
may
not
know
it
yet-
because
there
is
the
possibility
of
a
symptomatic
transmission
or
pre-symptomatic
transmission,
if
you
put
that
fabric
mask
on
that,
the
you
reduce
that
opportunity
to
transmit
to
someone
else.
So
that
was
the
key
thing
that
we
we
put
in
the
guidance
out
on
Friday.
That
was
new.
So
this.
C
It
is
a
lot
of
detail,
we
know
it's
not
a
simple
where
or
don't
wear
masks
and
that's
why
you
we
suggest
you
to
do
some
more
reading.
We've
got
infographics.
We
have
videos
that
help
explain
this
a
bit
better.
Also
for
those
of
you,
for
whom
English
is
not
a
first
language
or
living
in
other
parts
of
the
world,
go
to
the
wo
regional
websites
and
the
country,
websites
and
you'll
see
materials
there
in
your
languages
as
well.
C
There's
some
people
who
are
asking
why
we're
not
wearing
masks
and
that's
because
we
are
able
the
way
our
studio
team
has
set
this
up.
We
are
able
to
be
more
than
a
metre
apart,
so
we
don't
need
to
wear
masks
to
protect
I,
don't
need
to
wear
a
mask
to
protect
her
from
me
and
likewise
for
Mike.
So
that's
the
answer
on
that
one.
C
So
we
have
on
Facebook,
Fatima
sabor
on
Facebook
asks
what
are
the
transmission
modes
of
coated
from
an
asymptomatic
patient.
So,
as
we've
said
before,
when
someone
has
is
coughing
they're
pushing
the
virus
out.
So
if
a
person
doesn't
have
symptoms,
how
are
they
transmitting
the
virus
to
someone
else.
E
That
is
an
excellent
question
actually
speaks
to
that.
To
the
heart
of
the
issue
is:
to
what
extent
is
the
presence
of
the
virus
in
the
upper
wristband?
That's
a
difference
between
maybe
SARS
and
and
and
and
call
with
19and
MERS,
in
that
this
virus
is
present
on
the
upper
respiratory
tract
in
size
of
MERS
that
the
virus
tends
to
be
isolated
from
the
lower
respiratory
tract
and
therefore
it's
obviously
much
harder
for
that
virus
to
get
out.
It
has
to
be
expelled
as
suture
it's
harder
to
breathe
it
out.
E
So
in
this
case,
there's
no
question
that
the
the
viral
loads
that
have
been
estimated
in
the
upper
respiratory
tract
would
indicate
that
the
virus
is
there
in
its
present.
The
question
remains:
is
how
does
the
virus
get
from
being
inside
your
nose
or
inside
your
pharynx
to
being
on
somebody
else,
and
it's
fairly
obvious
in
a
symptomatic
patient
if
I
cough
or
I,
sneeze
or
I
contaminate
my
hands
with
the
cough
or
sneeze
and
then
touch
a
surface
that
someone
could
be
exposed
to
that
there?
E
The
question
and
the
good
question
is
well:
how
does
someone
who's
asymptomatic?
Do
that
and
there's
some
very
interesting
observational
studies
done
looking
at
how
is
that
potentially
happening?
What
is
the
the
root
of
that
and
in
some
cases
and
and
some
studies
have
been
done
on
this
around-
you
know,
singing
speaking
loudly
exertion,
maybe
in
a
gym
where
you're
breathing
very
heavily,
so
any
any
any
situation
in
which
you're
likely
to
express
air
under
pressure.
E
So
when
you
sing
or
you're
shouting
in
a
nightclub,
because
you
can't
hear
your
friend-
and
you
say
you
know,
can
you
hear
me
and
your
you're
close
by
and
you're
projecting
your
voice
at
someone?
Then
it's
clear
that
in
that
situation,
if
the
virus
is
presence
in
your
upper
respiratory
mucosa,
then
there's
every
likelihood
that
you
can
project
that
virus
and
some
of
the
foster
investigations
that
were
done,
for
example,
in
the
likes
of
Japan,
showed
that
some
of
these
environments,
like
in
gyms
and
in
choir
situations
and
in
nightclub
situations.
E
Where
they
got
that
transmission,
so
it's
really
interesting
to
look
at
that
dynamic.
So
there
is
a
mechanical
means
of
projecting
this
virus
and
clearly
that
has
that
is
playing
a
part
in
in
transmission.
There's
no
there's
no
question.
The
question
is
what
proportion
of
overall
transmission
has
been
driven
by
that
route
of
transmission,
and
then,
if
that
is
the
case,
then
is
the
what
we're
doing
now:
a
contact
tracing
and
everything
else.
E
So
well,
it's
not
we're
doing
that
if
all
of
the
diseases
will
spread,
but
the
other
group
of
what
what
has
been
proven.
The
opposite
is
countries
that
are
doing
really
good
Public
Health
work
really
investigating
clusters
and
finding
cases
and
identifying
contacts
in
quarantine
in
those
contacts
in
those
situations.
Countries
are
having
great
success
in
suppressing
the
infection,
so
there's
clear
that
both
symptomatic
and
asymptomatic
individuals
are
part
of
the
transmission
title.
E
The
question
is:
what
is
the
relative
contribution
of
each
group
to
the
overall
number
of
cases,
and
what
is
clear
is
that
if
we
can
remove
and
sir
identify
those
who
are
symptomatic
and
and
give
them
an
opportunity
to
be
isolated
and
cared
for
and
also
give
their
contacts,
the
same
opportunity
to
be
quarantined
with
support
and
that's
another
issue.
When
we
talk
about
things
like
quarantine,
it's
not
as
simple.
It's
not
a
simple
measure.
Someone
who
goes
into
quarantine
for
14
days
needs
to
be
supported
in
that
process.
E
E
We're
100
percent
of
the
population
have
to
effectively
go
into
quarantine
and
we
have
some
choices
to
make
as
a
society,
because
it
is
clear
if
we
can
identify
cases
and
their
contacts
and
we
ask
those
contacts
to
quarantine
themselves
and
we
support
them
in
that
quarantine,
that
that
can
be
a
very
successful
way
of
both
stopping
the
disease
and
avoiding
large-scale
lockdowns
of
future.
So.
A
D
Gender,
that's
another,
that's
an
excellent
question,
so
I
there's:
how
are
we
actually
finding
these
asymptomatic
people?
Where
do
they
come
from
many
of
them
early
on
in
the
outbreak
in
the
pandemic?
We
they
were
coming
from
contact
tracing,
so
these
were
close
contacts
of
known
symptomatic
cases
who
tend
to
be
family
members,
for
example,
because
a
lot
of
the
transmission
was
in
households,
so
they
would
be
loved
ones
that
live
in
the
house.
They
could
be
older,
they
could
be
younger
now.
E
Chief
with
broad
or
testing
or
more
popular,
but
at
the
core,
you
need
to
be
testing
the
suspect
cases.
So,
there's
no
point
just
doing
you
need
to
target
your
testing
and
target
that
testing
against
those
individuals
who
are
likely
to
have
the
disease,
so
you
can
identify
their
contacts
and
break
the
chains
of
transmission.
If,
in
addition
to
that
process,
you
couldn't
do
further
testing,
you
can,
for
example,
do
pre-emptive
testing
and
long-term
care
facilities
or
test
health
workers
or
other
things.
E
Then,
yes,
that's
a
good
way
of
managing
risk,
but
just
doing
blind
population-based
testing
without
doing
those
other
things.
I
think
at
this
stage
is
you'd
have
to
really
question
whether
that's
the
best
use
of
resources.
I
think
you
have
to
use
your
particularly
in
developing
countries
who
don't
have
access
to
massive
amounts
of
testing.
They
really
have
to
use
the
resources
carefully
and
they
have
to
use
them
wisely
and
they
have
to
use
them
tactically
and
I
do
think.
E
In
that
sense,
we
need
to
focus
in
on
diagnosing
suspect
cases,
identifying
their
contacts,
quarantine
in
contacts
supporting
those
contacts
in
quarantine
and
using
that
as
a
primary
strategy
and
testing
is
part
of
that.
If
you
have
a
further
capacity
to
test-
and
you
can
do
more
absolutely
please
do
you-
do
need
to
use
your
testing
as
part
of
your
surveillance
and
control
strategy
as
well
in
a
targeted
way
and.
D
What
we've
done
is
we've
tried
to
support
countries
based
on
the
type
of
transmission
scenario.
They're
in
you
know,
what
are
they
facing?
Do
they
have
a
few
cases?
Do
they
have
clusters
of
cases?
Do
they
have
you
know
widespread
community
transmission
and,
and
that
will
in
make
countries
have
to
prioritize
the
use
of
what
they
have,
and
so
what
we've
done
is
we've
tried
to
provide
guidance
to
support
them
in
in
the
best
use
of
the
resources
that
they
have
take.
C
D
That's
another
really
excellent
question.
We
should
do
more
of
these.
No
that's
a
really
excellent
question
and
that's
another
one
of
the
big
unknowns
is
it's
not
only
who
is
is
transmitting
to
others.
It's
when
are
they
transmitting
to
others,
and
so
data
here
is
very
preliminary
and
again
we're
working
with
a
number
of
countries
and
labs,
and-
and
we
ask
all
of
our
Member
States,
to
help
us
answer
these
questions
to
better
understand
when
people
are
most
infectious.
D
What
we
have
are
some
a
few
studies
again,
it's
limited
information
on
when
people
test
positive
through
PCR
testing
and
when
they
may
have
more
viral
load
is
what
we
say.
It's
more
particles
that
a
lot
of
virus
in
their
body
thank
you,
and
it
appears
from
very
limited
information
that
we
have
so
far
that
people
have
more
virus
in
their
body
at
or
around
the
time
that
they
develop
symptoms,
so
very
early
on
which
is
different
than
the
profile
that
we
saw
with
SARS.
D
And
so
that
means
we
we
don't
know
actually
when
people
are
most
infectious,
but
but
from
that
information.
People
with
with
more
virus
in
their
body
may
be
able
to
spread
more
early
on
an
infection
and
then
that
tails
off
well,
we
don't
know
well
yet,
is
sort
of
the
upper
bound
of
like
how
long
are
people
infectious
there's
some
preliminary
studies
from
Germany
from
the
United
States.
D
That
suggest
that
that
it
could
be
up
to
eight
nine
days
for
my
old
patients,
but
it
could
be
a
lot
longer
for
people
who
are
more
severely
ill
and
that's
why
it's
really
important
that
cases
are
isolated
and
cared
for
appropriately,
so
that
that
we
we
prevent
that
potential
for
onward
transmission.
But
again
it's
still
early
days
and
it's
still,
you
know
we're
trying
to
gather
this
information
to
help
us
really
understand
when
people
are
most
infectious.
E
It's
a
it's
very
important
across
all
of
them
affections
disease
control.
If
we
look
at
a
bola
I'm
dealing
with
another
of
all
of
outbreak
in
Congo
right
now,
people
tend
not
to
be
infectious
at
all
until
they
get
their
fever
and
sometimes
for
a
number
of
days
afterwards.
So
if
you
can
detect
everyone
that
has
the
fever,
then
you
sure
that
you
were
that
you're,
you
you're
able
to
protect
others
and
break
the
chains
of
transmission.
E
It's
the
same
was
the
same
answers,
because
people
didn't
tend
to
be
infectious
as
early
in
the
course
of
disease,
because
the
virus
was
in
their
lower
respiratory
airway.
It
was
harder
to
infect
others.
So
it's
both.
You
need
to
look
at
the
timing
at
which
someone
becomes
infectious
and
also
where
they're
being
infectious
from
how
easy
it
is
for
them
to
pass
the
disease
from
one
person
to
another.
So
in
this
case,
which
now
as
we
look
at
Co
819,
we
have
an
infectious
pathogen.
E
That's
present
in
the
upper
airway,
for
which
the
viral
loads
are
peaking
at
the
time
that
you're
just
beginning
to
get
sick,
or
that
means
you
could
be
in
the
restaurant
feeling
perfectly
well
and
start
to
get
a
fever
some.
What
you're
feeling
okay,
but
that's
the
moment
of
which
your
viral
load
could
be
actually
quite
high
and
and
I
think
they're.
The
kind
of
reasons
why
mask
guidance
and
others
is
to
say
well
in
situations
you
can't
physically
distance.
There
is
this
period
of
time.
E
When
you
know
even
a
professor
of
infectious
diseases
themselves,
wouldn't
know
that
I'm
getting
covert
there
is
that
hours
or
days
in
which
you're
not
that
unwell
or
you
could
be
becoming
unwell,
you're,
not
aware
of
your
status,
and
it's
because
the
disease
can
spread
at
that
moment
that
the
disease
is
so
contagious.
That's
why
it's
spread
around
the
world
in
such
an
uncontained
ways,
because
it's
hard
to
stop
this
virus.
If.
C
E
Is
still
possible
if
this
virus
was
easy
to
stop
everyone
right,
it's
not
easy
to
stop.
It
isn't
easy
to
stop,
but
what
some
countries
have
shown
many
countries
are
shown
is,
if
you
go
at
this
in
a
very
systematic
way,
and
you
use
a
comprehensive
approach
that
there
is
enough
stop
ability
in
the
virus.
It's
not
so
transmissible
that
you
cannot
suppress.
We've
seen
that
with
physical
measures,
social
distancing,
we've
seen
it
with
with
surveillance.
E
You
put
all
of
these
things
together
and
you
just
double
down
on
your
bets
and
say
we're
going
to
do
everything.
Countries
have
clearly
song
shown
that
you
could
have
an
impact
on
the
virus
transmission
and
you
can
bring
transmission
down
to
an
acceptable
level
or
even
to
no
level,
as
our
colleagues
in
New
Zealand
have
recently
demonstrated.
So
I
think
that's
an
important
part
of
this.
It's
one
thing.
You
know
we
have
to
admit,
and
everyone
needs
and
we've
seen
it.
E
This
is
not
an
easy
virus
to
stop,
but
we
have
to
do
our
best
and
just
because
something
is
not
easy
to
stop
it.
You
can't
throw
up
your
hands
and
say
well,
it
can't
be
stopped,
there's
a
difference
between
not
easy
to
stuff
and
can't
be
stopped
and
I
think.
While
there
are
still
many
unknowns,
we
know
enough.
E
I
think
that
we
need
to
and
if
we're
coming
into
a
period
we
people
have
seen
now
in
Europe
and
North
America,
the
disease
is
is
is
is
is
to
a
great
extent
on
the
decrease
of
many
countries,
but
that
is
not
the
case
in
Central
Asia.
That
is
not
the
case
in
Africa.
That
is
not
the
case
again
in
the
Middle
East.
That
is
not
the
case
in
Latin,
America
I
think
it.
E
We've
seen
it
work
in
other
situations,
yeah,
and
we
wish
those
those
come.
That's
what
we're
here
to
provide
the
best
possible
technical
advice.
No
one
has
all
the
answers.
No
one
has
all
the
knowledge.
The
real
trick
is
pulling
all
of
that
knowledge.
Pulling
those
answers
together
together
and
working
together
to
give
the
best
possible
scientific
advice
that
drives
policy
at
national
level.
In
the
end
of
the
day,
w-h-o
doesn't
tell
countries
what
to
do.
E
Countries
decide
they
do
in
terms
of
policy,
and
they
gather
their
own
scientific
information
and
you've
seen
that
many
countries
have
their
own
scientific
committees.
They
have
their
own
modelling
groups,
they
have
their
own
clinical
groups.
Our
job
in
WTO
is
to
synthesize
that
as
a
global
level,
because
some
countries
don't
have
access
to
that
knowledge,
but
also
it's
always
good,
to
have
a
second
opinion.
E
It's
always
good
to
have
your
own
national
this
process
and
then
look
at
what
the
rest
of
the
world
is
doing
and
the
more
we
do
that
and
the
more
we
learn
from
each
other,
the
more
likely
it
is.
We
will
gain
new
knowledge
and
then,
in
one
month's
time,
two
months
time
in
five
months
time,
we
will
know
more
and
we'll
be
sitting
at
this
desk.
Answering
other
unknown
questions
about
this
virus
and
I
think
that
will
continue.
Look
at
Ebola
we're
still
asking
questions
about.
E
D
I
think
I
think
it's
important
that
people
understand
that
what
we
do
here
is
in
this
consolidation
in
this
summarizing
in
this
pulling
together
is
its
its
its
science,
its
debate,
its
public
health,
its
practical,
its
it's
iterative.
It
changes
all
the
time
and
it's
dynamic
and,
as
Mike
said,
every
question
we
answer,
we
have
10
more,
so
we're
trying
to
slowly
gain
knowledge
and
slowly
gain
a
better
understanding
of
you
know
what
is
the
transmission?
D
What
is
the
severity
and
then
how
do
we
stop
this
and,
as
Mike
has
said,
we
do
have
the
tools.
We
have
a
number
of
tools
that
are
shown
to
be
able
to
suppress
transmission
and
we
focus
on
those
and
we
double
down
and
we
work
really
hard
while
being
open
to
innovation,
and
so,
even
with
this
mask
guidance
that
came
out
the
innovation
and
the
fabrics
and
I
mean
that
is
something
that
should
be
celebrated.
It
is
welcomed,
and-
and
we
need
more
of
that,
so
we
work
with
all
of
you.
D
C
E
And
it
is,
it
is
a
debate
and
you
know
you
can
see
yesterday
and,
as
you
said,
quite
a
big
reaction
to
to
Maria's
response
on
the
question,
and
so
there
should
be.
We
need
that
debate
and
if
people
out
there,
if
journalists
and
the
public
think
that
we're
we're
straying
away
from
evidence,
then
fine-
you
know
that's
what
this
is
for
if
they
think
there
is
in
the
basis
for
what
we're
saying,
then
let's
have
that
debate
one
on
one.
That's
why
we're
here?
That's
we
didn't!
That
was
not
intended.
E
That
was
not
the
intention
of
the
statement,
but
you
know
what
it's
better
to
be
having
this
narrative
having
this
discussion,
it's
not
behind
closed
doors.
It's
happening
in
the
open,
we're
happy
to
continue
this
dialogue
because
we're
open
and
we're
transparent,
and
we
want
that
and
we
are
concerned
if
people
misinterpret
what
we
say,
we
don't
want
that
to
be
the
case,
so
I
I,
really.
You
know
this
is
a
really
positive
way
of
engaging
on
these
issues,
but
we
do
need
to
separate
what
is
WS
policy.
E
What
we're
putting
out
as
documents
saying
this
is
what
the
world
needs
to
do
from
what
is
a
response
to
a
question
in
which
one
part
of
that
question
was
was
was
clearly
misinterpreted,
or
maybe
we
didn't
use
the
most
elegant
words
to
explain
that.
But
that's
I
think
is
that
I
don't
see
that
as
a
challenge,
I
see
that
as
an
opportunity
to
better
explain
where
we
are
with
issues
around
transmission,
which
has
been
a
good
opportunity
today.
So.
C
Wrap
but
the
we're
out
here
and
gotta
answer
those
questions.
We've
got
one
from
best
squirrel
rocky.
You
keep
in
line
dr.
Ryan,
she's
reported
with
Lifehacker
and
wants
to
know
I
already
know
we
don't
have
an
answer
to
this
one.
But
let's
it's
an
interesting
question:
do
we
know
how
much
transmission
is
from
people
who
currently
have
no
symptoms,
so
not
truly
asymptomatic,
but
those
pre-symptomatic
people
who
might
be
out
having
lunch
today,
not
knowing
that
they
will
be
feeling
sick
too?
Do
we
have
any
estimate
or
guesstimate
around
something
like
that?
The.
D
Short
answer
is
no
I
mean
the
short
answer
is
these
are
the
types
of
studies
that
we
need?
We
need
to
better
understand,
which
is
why
all
of
these
elements
of
physical
distancing
and
hand
washing
a
hand,
hygiene
and
respiratory
etiquette
and,
following
the
leaders
stay
at
home
orders
if,
if
necessary,
that's
why?
All
of
that
is
really
really
critical.
Why
you
wear
a
mask
in
areas
of
community
transmission
and
you
can't
do
physical
distancing
it's
why
all
of
this
comprehensive
approach
is
critical.
C
Sarina
churn
also
asked
a
question:
do
you
think
there's
new
modes
of
transmission
that
will
come
out
so
at
the
moment
we
know
it's
droplets
and
those
droplets
either
fly
straight.
You
know
from
my
mouth
to
your
eyeballs
or
they
fall
on
the
surface,
and
then
somebody
touches
the
surface
and
touches
their
own
eyeballs
or
mouth
or
nose.
C
E
May
do
I
mean
certainly
there's
been
speculation
around
fecal
oral
or
transmission
to
the
gastrointestinal.
Tide
on't
see
much
evidence
at
this
point
for
that
I've
seen
studies
that
show
the
presence
of
RNA
in
viral
particles,
but
we
haven't
seen
any
clear
demonstration
of
transmission
by
that
route
and
that
will
be
a
concern
if
that
were
to
be
the
case.
But
clearly
at
this
point,
the
the
the
overwhelming
evidence
points
to
a
respiratory
droplets
spread
infection
are
spread
through
four
formats,
a
contamination
of
your
respiratory
MCOs
or
ocular
mucosa.
E
D
That
is
the
aerosol
in
areas
in
hospitals
where
they're
performing
these
aerosol
generating
procedures
where
they
can
make
smaller,
more
fine,
fine
particles,
that's
where
we
make
different
recommendations
for
healthcare
workers,
and
we
recommend
airborne
precautions.
So
I
just
wanted
to
highlight
that
in
and
put
in
in
health
facilities
thanks.
C
C
When
we
do
these
live
sessions
Mike
you
might
want
to
take
off
your
microphone
and
get
back
to
leading
the
response.
Better
I'll
be
quick,
so
our
LinkedIn
followers
have
come
from
Argentina
Malaysia
Namibia,
the
u.s.
Mangla
Portugal
Netherlands
India
Indonesia
Macedonia
Cambodia
Ethiopia
Belize,
Pakistan,
India,
Colombia,
Guatemala,
I'm,
only
half
way
through
Namibia
Vietnam
England,
Nicaragua,
Turkey,
Mauritania,
Malaysia
Iran,
the
Democratic
Republic
of
the
Congo
Nigeria
Brazil
Poland
France
Venezuela,
Egypt,
Mexico,
Bahrain,
Tanzania,
Kenya,
Italy,
Spain,
Bolivia,
Sudan,
Iraq,
Afghanistan,
Saudi,
Arabia
Canada
and
a
sweaty
knee.
Thank
you
so
much
for
following
us.
C
On
whatever
platform
you
followed
us
on
today,
keep
tuning
in
for
other
Facebook
lives
check
out
your
regional
office
as
well.
They
do
press
conferences
multiple
times
per
week.
Look
at
the
whu-oh
website
for
your
country
office
for
the.
If
there's
a
whu-oh
office
in
your
country,
once
again,
I'd
like
to
thank
dr.
Maria,
Van,
Kirk
Kove,
our
technical
lead
for
Kovac
for
being
with
us
and
dr.
Mike
Ryan,
the
head
of
W
chose
emergencies,
program,
I'm,
Nika
Alexander
from
the
communications
team
here
at
whu-oh,
thanks
for
being
with
us
for.