An HIV vaccine is what the world needs now
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i’m a laboratory-based scientist
and for the last 25 years of my career
i’ve been trying to make a vaccine to
hiv
and now we have three vaccines for
covert
in less than a year how did this happen
well the covet vaccines benefited a lot
from the the years of investment
in hiv vaccines and what i want to tell
you about today
is how we can use that momentum to speed
up the development
of an hiv vaccine but first let’s look
at these two viruses
they certainly have some similarities as
you can see they are small microscopic
viruses and you need very powerful
microscopes to see them
but there’s also some significant
differences so
sar’s curvy ii which is the virus that
causes covet 19
is spread via the respiratory root so
that’s simply breathing
and it means that everybody is
susceptible this virus causes an acute
infection
that means it’s very short-lived and the
body is able to clear the virus
and as we know most that happens in most
people
and that’s because our bodies make an
immune response to the virus
particularly neutralizing antibodies
which develop in almost
everybody another important feature is
that this virus
is very stable so the 60 million people
around the world that have been
infected with this virus are infected
with a very related virus
there are some differences but it is
very similar
now hiv in contrast causes a chronic
infection
and that means it it’s it’s a lifelong
infection
and that’s because this virus integrates
into
our genetic material into our dna
the other major factor is that the
neutralizing antibody response here is
very slow and ineffective and then
another major
hurdle for hiv vaccine development is
the virus mutates and it really is a
moving target
now vaccines have been one of our most
successful ways of dealing with
infectious diseases
and most vaccines work by in inducing
neutralizing antibodies these are part
of our immune response
and neutralizing antibodies work because
they
specifically bind to parts of the virus
in this case it’s the spike protein
which surrounds the
um the sars cov2 particle
so it’s actually a physical interaction
the the antibody
binds to the spike and stops the virus
from infecting cells and that’s what it
means by
uh by neutralizing so let’s have a
closer look at this
sars covi2 protein so this is what
causes the spikes or the corona around
the virus
and scientists have been able to
look at this at what’s called a very
high resolution and in fact
again it’s hiv scientists who turned
their attention
to looking at the sars curvy ii
protein partly that’s because of the
urgency but also because a lot of
funding was made available
for people to study covert 19. but
what we what we’ve learned from from the
structure
of the spike protein is that the the
part that’s targeted by the antibodies
is a very focused part that’s the part
that’s colored in
in red and so that is the major target
that we’re looking
because that is the part of the protein
that binds
to the cells now
a number of different vaccines have been
made against covet 19
and again it’s really benefited from the
vaccine development that’s been taking
place for for decades
with hiv and so this just shows you some
of the different approaches that have
been taken
and many of you will know i think then
our household names some of these uh
these vaccine manufacturers so the
genetic vaccines which are
composed of the rna or the dna
of the virus of the spike protein are
used to stimulate an immune response
these same genes are also put into what
is called a viral vector
so it’s a harmless virus to actually
carry these genes into the body
almost like a trojan horse so in these
kinds of vaccines
the body is in fact making the spike
protein
we’re actually making our own vaccine in
a way
the third kind of vaccine is called a
protein vaccine
and this is where we make the protein in
the laboratory and then
you know use that to immunize people and
this is a much more traditional
approach to vaccine development and it
it’s it’s it takes a lot longer and is
actually much more expensive
so there’s certainly and it’s been
widely reported in the media
about you know this incredible effort to
develop
a covert vaccine and now we know we
already have three
that have shown that they work that they
have a high level of efficacy
the two rna vaccines were shown to have
over 90
efficacy and the vectored vaccine
was also had very good efficacy but as
you can see from what’s called this
pipeline
there are another 10 that are still
undergoing testing and certainly are um
you know we we suspect that they’re also
going to work
and you can see that in the earlier
phases of of testing there are a large
number of vaccines so we have a very
very robust pipeline
for covert vaccine development and
although none have been licensed as yet
that is also very very imminent
in contrast in the 20 years
of doing hiv vaccine trials we’ve only
ever done
six efficacy trials um in the in in 20
years so
just to give you a sense of uh you know
the difference uh
and how we’re tackling these two viruses
but i don’t want to make it sound as if
hiv vaccine development is easy because
it isn’t it’s actually one of the
biggest challenges of our time
and that’s really because this virus
does change
so we the laboratory that
that i run at the at the at the nicd
has been looking at how to develop these
broadly neutralizing antibodies in
infected people
and we discovered during this process
that the virus
is changing to create the kinds of
stimuli that you need to to get the
right kinds of antibodies
and so this this evolutionary process
is now being incorporated into vaccine
design
and so the the the paradigm is is that
we’ll need to have different
different vaccines in order to shepherd
the antibody response along so it can
become
a neutralizing antibody response and
that’s just shown graphically here
um so the um this is the
the the equivalent of the spike protein
in hiv is called the envelope protein
and so each of those different colors
shows that it’s a slightly different
envelope protein
in order to to basically as i say coax
the immune response along the right
pathway to make neutralizing antibodies
so certainly in terms of vaccine
development you know hiv presents
you know some significant challenges so
i
am participated in a covert vaccine
trial
the novovax trial that’s been run by
this university
and i did that because i really believe
in vaccines i believe in the power of
vaccines
and also because i am vulnerable just
like everybody else to
you know to being infected by sales
curvy 2.
and so i had two vaccinations
and you know i sort of imagined this uh
protein circulating in my body and my
b cells trying to you know hunt it down
so it could
produce the right kinds of antibodies in
order to you know to protect me
um and uh you know during this time one
kept one keeps a vaccine diary
you keep track of your um you know your
temperatures where there’s any swelling
or redness
and there really was very minor uh
pretty similar to an insect bite
that really resolved within a few days
um
of course i don’t know yet if i’m on the
placebo or the active arm of the
of the vaccine that will only be be
found out later
and that’s really a critical thing for
um
you know for determining how a vaccine
works is to measure the immune responses
in people who’ve been vaccinated
and to determine what’s called the
correlate of protection so we need to
know what levels of antibodies
the vaccine needs to stimulate in order
to protect people from infection and
that’s what these trials are going to
show
so a very critical thing and in fact
once we have the correlate of protection
actually the vaccine development process
is going to speed up even further
but i also you know like you know we’ve
been learning as we go
with this epidemic that we still have
many unknowns
so we don’t know how long immunity is
going to last we don’t know if these
vaccines are going to work for everybody
um though there’s certainly good signs
that they do work in older people who of
course are a major target group
um we’re not sure if we’re measuring
exactly the right immune responses
um because there may be other things
that we
you know are still to discover and i
think a very critical thing is um
you know will the virus change in the
same way that it changes with hiv
and represent a problem you know once
the a number of people
um have immunity to sars it’s going to
put pressure on the virus and so that is
one of the things that we certainly need
to keep
track of so now i want to look at the
global devastation caused by these two
epidemics so the top
graph shows the number of deaths caused
by sars kovi ii per week
since the start of the outbreak and what
you can see is in the purple is the
first wave that occurred in europe and
you can see the resurgence now that’s
happening
and then you can see the high level
and ongoing uh level of deaths in the
americas
and what is most um disturbing about
this graph
is that these the resurgence levels are
higher than the initial levels
and really speaks to our the urgent need
to start deploying these
um active these efficacious vaccines
because if we don’t um these waves will
keep happening
this virus will become endemic and it
will keep spreading amongst susceptible
people so so far
in 11 months 1.4 million people have
died of covet 19
and we certainly don’t want to be
getting to the levels that we see with
hiv
of 35 million people so
the reason why there’s 35 million people
who have died from hiv is because hiv
has been with us for a very long time
and as you know we don’t have a vaccine
but what we do have is we do have good
antiretroviral therapies
and you can see the effect of those on
on the graph below
so at the peak of the aids epidemic
approximately 1.6 million people were
dying per year
and that decline was when antiretroviral
therapy started being widely used
but we it’s not going to get us to zero
because antiretroviral therapy treats
infected people what we need
is we need to prevent people from
getting infected and that’s why we need
a vaccine
so we need that vaccine to get that
curve right down
just last year 2019 over 700 000 people
died of hiv so the other important thing
about this graph
is the colors so you can see that
that it’s mostly red and that’s because
hiv
is mostly affects the african continent
but it also we also know historically
that
vaccine development or africa has been
very neglected in terms of developing
vaccines for diseases
that affect the african continent
so what can we learn from covet 19 that
will help us to develop
an hiv vaccine more rapidly so
what we need to be doing is testing
developing and testing multiple
candidates
we need a robust pipeline the same way
that we’re doing with covert we need to
be testing lots of different concepts
um testing them all at the same time we
certainly need to be testing the mrna
vaccines
um which were originally developed for
hiv but you know now are being tested
for covert we need to go back
and we need to be doing that we also
need to run parallel processes so while
we’re testing we need to be
manufacturing and we need to be seeking
approvals
it’s high risk but it’s
it’s it’s it fast tracks the process and
we certainly need more money
so covert 19 the amount of money spent
on covert 19 is 8 to 10 times higher
than the funding for hiv vaccines in any
given year
and we know that money drives innovation
it attracts
the best scientists and the best
industries into the
um you know into this area um
it helps us run more trials vaccine
development is expensive and it is
higher risk
we also need more industry involvement
we’ve certainly seen that in covet
many industries including industries
have never been involved in vaccine
development
are now getting involved but we do need
to incentivize them
and and one of the ways to incentivize
them is of course to give them advance
commitments
um so our governments need to do that
they need to say that we will buy the
vaccine
uh if it’s shown to be safe and
efficacious
there’s no doubt um that the covert
vaccine is going to have a major impact
it’s going to turn this epidemic around
it’ll save lives and it’ll save
livelihoods
what we need now is to also develop a
vaccine against hiv
so that we can do the same we need to
attract the best
people into this area we need to use
what we’ve learned
in developing covert vaccines we need to
apply that to hiv
so that we can have an aids-free world
thank
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you