and a year and a half later I slipped out of bed one day

and I collapsed on the floor.

My parents immediately thought, "Oh, it's polio".

It would be hard to imagine what a world without vaccines would be like.

It would really be quite horrible.

There would be outbreaks of disease regularly, all over the world.

The true deep impact, and the global impact, of vaccines

just can't be underestimated.

My grandmother, she used to tell a story

about when they would hear the bells on a hearse

going down the high street, a funeral.

She said as children they would rush to their nursery window

to see if there were white ribbons on the horses

which meant it was a child funeral,

and they happened several times a week.

It typically affected children.

One of the names for polio was infantile paralysis.

It's quite difficult to imagine a world without vaccines.

Life expectancy would be a lot lower.

People would have to lock themselves away

and only come out again when it was safe.

And ironically,

there would be such a demand

to do something that vaccines

would inevitably emerge.

Vaccines are likely the most important public health intervention

of the last 100 years.

They've saved over a billion lives.

With the roll out of vaccines

we have seen a massive reduction in child mortality

in sub-Saharan Africa.

I am born in the Gambia

and growing up there I lost a brother to measles.

To lose somebody at a very premature age

from a disease preventable by vaccines is absolutely devastating.

Vaccines can prevent cancer and there are two cancer vaccines.

With the roll out of the current malaria vaccine

we are expecting to see a reduction of 40% of malaria deaths.

You could bring a vaccine to people

but will they take it?

Anti-vaccination fears have been around for over a century.

We know from the 1850s, when Jenner first developed smallpox vaccine

there were actually quite a few protests.

A lot of it was about civil rights and libertarian values.

There were arguments saying that it was poisonous,

that children who received a smallpox vaccine

would develop bovine or cow-like traits.

A lot of it was just a genuine knowledge void

that a lot of people had in the 1850s that they still have today.

On the one hand we have the really hardcore anti-vaccination groups,

but a lot of people are actually in the middle,

and I think what we need to do is just engage with people

where they are and where they are talking

and not discount their real concerns.

People want to understand things, they want to be confident,

they might be afraid of needles.

We have to understand their context and where they're coming from

and what are their past experiences with health and vaccines.

We have to ensure that people understand it and they will take it.

A world without vaccines, it would be a matter of economic status

where the children of the wealthy will have access to healthcare

will be surviving.

Vaccines are the only public health intervention that can bring equality.

So women don't need to have five, 10 children

just to see three of them grow to old age.

This isn't about just individual rights,

when you take a vaccine it's protecting yourself,

it's protecting your family, and it's protecting your community.

It's not just a personal choice,

it's a moral choice as well that affects other people.

It's impossible to emphasise how important vaccines are.

And the reason that we don't often realise that they're important

is that we've eradicated many of these diseases.

The idea that vaccines could be a victim of their own success,

it's about taking things for granted, isn't it?

And not looking behind

what the privileges we have in the modern world are,

and what makes it the modern world,

and makes it a safe place for most of us to be,

and vaccines are absolutely at the heart of that.

They're fundamental.