A sobering update on zika today.
The nation's top health officials
warning that the zika virus appears to be
a lot scarier than first thought.
A stark warning that the haunting images
of babies born with microcephaly in Brazil,
abnormally small heads and brains,
are becoming a very real concern in the U.S.
Birth defects caused by zika virus
make it a terrifying disease,
but it pales in comparison
to a far worse infection  
that plaqued us through much of the 20th century.
Many of us think of German measles
as just another one of those harmless childhood diseases
and that is true, it can be.
But it also can be, as polio was,
one of mankind's worst cripplers.
A severe rubella epidemic
swept the United States in 1964-65
leaving behind literally thousands of damaged babies
whose mothers had acquired rubella during pregnancy.
Although rubella was 
a mild infection of children
It wasn't mild at all
if it infected a pregnant woman 
during her first trimester
Then she could go on 
to deliver babies
who had severe congenital abnormalities;
abnormalities of the eye, blindness,
the ear, deafness,
the heart, causing terrible abnormalities
of the heart structure,
and ironically, it's a virus that when it 
inefected women in the first trimester
could cause autism.
In fact, in 1964 and '65,
rubella was so feared
that approximately 5,000 U.S. women
infected with the virus
chose to surgically abort their pregnancies.
And 6,000 more lost fetuses to spontaneous abortions.
At the time Dr. Stanley Plotkin 
was working at the Wistar Institute in Philadelphia.
As part of my work at Wistar
and also the Children's Hospital
I was seeing both mothers who were
concerned about whether to have abortions
because of rubella in them
and the possibility of intrauterin 
rubella in their infants
and also diagnosing 
the congenital syndrome.
Those are experiences that certainly mark one
and give impetus to... to trying to prevent
things like that from ever happening again.
[Baby crying]
Plotkin would develop a rubella vaccine
to protect a new generation.
His first order of business?
To acquire a strain of the virus.
The virus was isolated from one of the fetuses that
were aborted at the mother's request
because she had acquired rubella.
And indeed, when we obtained the fetus
it was clear that the virus had damaged the fetus.
Dr. Plotkin's lab alone received material
from roughly 35 pregnancies terminated
because of rubella infection.
His RA 27/3 strain of rubella virus
came from the third organ, the lungs, 
of the 27th damaged fetus he had received
during the 1964 - '65 outbreak.
To make his vaccine
Plotkin would need cells in which to grow the virus.
Cells are like tiny factories,
making proteins and enzymes
needed by the cell and by the body.
A genetic code, or DNA,
provides the bluprint,
instructing the cell’s components on what to do.
Viruses also contain a genetic code,
but they can’t make their own proteins,
so they need to hijack
the protein-making machinery of a cell
to reproduce.
Once inside a cell
the virus releases its genetic code
which takes over the protein-making machinery.
The cell follows these new instructions
and becomes an assembly line,
generating thousands and thousands more virus particles. 
These new virus particles
are an exact copy of the original virus
and soon leave the cell
so they can infect other cells.
In the 1960s, researchers had typically used 
animal cells to grow viruses for vaccines.
But the head of vaccine development at Merck,
Maurice Hilleman, had recently discovered
something frightening about animal cells
while working to improve Jonas Salk’s polio vaccine.
What Dr. Hilleman found was that
the monkey kidney cells that were used
both by Jonas Salk when he made his vaccine
or Albert Sabin when he made his vaccine
were contaminated with a monkey virus.
It was the 40th known monkey virus of man
It was called SV40
and he found out soon enough that it also caused
cancer in experimental animals.
This made people realize
that cells from animals,
as primary cells from animals
could be contaminated with
a variety of so-called extraneous agents,
that is viruses that you don't want in a vaccine.
The challenge for Plotkin
would be to find a type of cell
that didn’t carry the risk of contaminating viruses.
It so happened that across the hall
at the Wistar Institute,
Dr. Leonard Hayflick had been experimenting
to better understand how and why we age.
He did it using human fetal cells.
Human diploid fibroblast cells are clean.
That is to say coming from fetal tissue
they have no agents that you don't want
in your vaccine.
So I decided that
in order to avoid any problems of so-called
extraneous agents
that I would use human cells for the attenuation.
Hayflick had received his fetal cells
from Sven Gard at the Karolinska Institute in Sweden,
the organization responsible for the Nobel Prize.
Gard had obtained the fetal tissue
from an elective abortion performed in the early 1960s.
A fact that would later cause controversy.
Because he was at the Wistar Institute at the time
Hayflick named his line of cells WI-38 cells.
A cell bank had been established at Wistar
so that one didn't have to cultivate any new cells
but one could go back to the freezer
take out an ampule of the cells, grow them up
and then make a vaccine lot
in those cells.
I started to use my experience
with polio vaccine actually
to attenuate the virus,
meaning, of course, to weaken it
to the point where it would still immunize
but would no longer cause disease.
Weakening viruses by attenuation
is based on the principle of selection.
Like with evolution, survival of the fittest
is dictated by one's environment.
Change the environment,
say from the human body to human cells in a petri dish,
and you suddenly change the whole game.
Now, if you lower the temperature of the petri dish
below that of the human body,
all bets are off.
The vast majority of virus particles
will simply cease to reproduce.
But a few will find they can adapt
to this new environment.
By passing these select virus particles
over and over through the laboratory cultures,
the virus population is soon made up
of only those particles
that can grow well in the petri dish
but can't grow well in the human body.
Plotkin's temperature adaptation in fetal cells
proved to be an efficient and effective means
of attenuating his vaccine.
And the work showed great promise.
But not everyone thought so.
This was a new concept
and there was
great difficulty in getting the regulatory authorities
to accept the idea of using those cells
to make vaccines.
The attitude was
better the devil we know than the devil we don't know.
Plotkin couldn't have predicted
just how much resistance
his use of fetal cells would face. 
Not only from the regulatory authorities,
but also from his fellow scientists.
At the time there was a dogma
that human cells in particular
could not be passed numerous times
or if they did they would transform
to cancerous-type cells.
But Hayflick and Moorhead showed
that indeed the human cells would
replicate, would multiply
a limited number of times
and then they would literally senesce.
That is they would grow old
and the cultures would stop,
would, in effect, die.
A meeting about rubella vaccines
convened at the National Institutes of Health.
And Plotkin was part of a minority
advocating for the use of human fetal cells.
Among those against the idea
was oral polio vaccine developer, Albert Sabin.
He got up towards the end of the meeting
and made a statement
about why diploid cells shold not be used.
But he had no evidence.
And I remember very clearly saying to myself
the biblical phrase,
"the Lord has delivered him into my hands."
Plotkin addressed the meeting
pointing out that Sabin's statements
were not based in fact
and that all the evidence showed
fetal cells were indeed safe.
The audience gave me an ovation.
Now, that was not for me personally
but simply because scientists in general
don't like ex cathedra statements
and it was clear
that most of them had been convinced
that the prejudice against
diploid cells was not founded.
If his scientific peers were beginning to come around,
those in the religious community
were still grappling
with the morality of using human fetal cells,
even when developing a life-saving vaccine.
Indeed some controversy did arise
because the cells
that were used to grow the virus
were obtained from a normal fetus.
This fact raised questions
among anti-abortion advocates
and ultimately drew the attention
then headed by Cardinal Joseph Ratzinger,
who would later become Pope Benedict XVI.
While the Academy weighed the heavy toll
of using cells from an elective abortion,
Ratzinger ultimately cleared parishoners
to use vaccines developed with fetal cells
to avoid the devestating dangers to human health
especially from rubella.
Their consensus view is that
as the cells were not derived specifically
to develop the vaccine,
and in as much as
one is not doing new abortions
for every vaccine lot,
one is going back to cells
that were frozen in the early 1960s,
so that no...
no immoral act is taking place
according to those theologians.
Now, I am sure there are
other extreme points of view,
and from my point of view,
personal point of view,
having seen the suffering
of families with
congenital rubella syndrome infants,
I consider that what was done is
100% moral.
The spectre of another rubella epidemic was looming.
And Plotkin understood,
he wasn't the only one racing to head it off.
Two other formidable forces
were also hard at work:
the U.S. government
and the greatest vaccine innovator of all time,
Maurice Hilleman.
The NIH at the same time was
propagating the virus in
bovine kidney
for purpose of attenuation.
Hilleman found the NIH strain
wasn't weak enough.
So I said well, I guess maybe
I should put it through ducks
and attnuate it, which I did.
Now we had the two viruses.
So we used what was called
the HPV-77 Duck
and that became the vaccine.
By 1969, Plotkin had finalized his work
on the RA 27/3 strain of rubella vaccine,
which was poised to prevent
the next impending outbreak.
But the U.S. regulatory authorities
continued to question his use of human fetal cells.
With the resources of Merck behind him,
Hilleman's duck cell rubella vaccine
was licensed in the U.S. that year.
Plotkin's was passed over.
The British had a different attitude 
about human diploid cells...
... from early on.
That is, they were convinced that
the objections to diploid cells were nonsense.
And so they took up the diploid strain
and started using it in continental Europe and the U.K.
at about the same time
as rubella vaccination started in this country.
With Hilleman's vaccine working in the U.S.
and Plotkin's in the U.K.,
the rubella outbreaks expected in the early 1970s
never happened.
20,000 cases of congenital rubella syndrome
were avoided,
5,000 surgical abortions prevented,
and 6,000 additional spontaneous abortions diverted.
Vaccines had again removed a terror from our midst.
In the U.S. Hilleman's rubella vaccine was working
and the science behind Plotkin's use of fetal cells
was slowly gaining acceptance.
Throughout the 1970s, the safety and effectiveness
of each vaccine was closely watched.
It became clear that the immunity
that was produced by the various strains
was different.
And at a certain point Maurice Hilleman
came to me and said,
"You know, we think that the RA 27/3 strain
is better than what we're using
and we would like to produce it."
For Maurice it was always about the science,
it was always about the data.
If there were data showing that
Dr. Plotkin's vaccine was a better vaccine than his
then fine, we'll use Dr. Plotkin's vaccine.
The ironic thing is that human diploid cells
are now considered to be the gold standard
of the acceptable cell substrate.
And there again one sees the evolution of science:
what was a heresy at the beginning
is now the orthodoxy.
In 1979, Plotkin's RA 27/3 rubella vaccine
was licensed for use in the U.S.
By 2005 rubella was eliminated
from the United States completely.
Today, fetal cells are also used to make hepatitis A vaccine,
the chickenpox vaccine, and a vaccine against rabies,
one of humankind's most feared diseases.
As a physician, unquestionably
the desire to prevent disease,
even more than to cure disease,
is a driving force.
And I have to admit that
the elimination of rubella
from the United States,
the elimination of rubella
from the western hemisphere
is something that pleases me greatly.
So yes, there's satisfaction,
but there's always more to be done.
And I maintain enthusiasm because
I see progress and, um...
... but even if I didn't
I think I would still want to
try to move things forward.
