Hello and welcome to more or less on the BBC World Service, with a show which likes to

throw numbers at any problem and I'm Tim Haferd.

This week the Delta variant.

This strain of the coronavirus was first identified in India, fueling a huge wave of cases and

deaths.

It's now spreading around the world, becoming the most dominant strain in many countries.

This week we take a look at the numbers.

Here is the Delta variant spreading, how is it different to previous waves and what can

we done to stop it?

Professor Asuragani, chair in infectious disease epidemiology at Imperial College London,

has made it her career to track the model diseases.

Work has never been so busy since the pandemic began.

Yeah, it's been really a bit of a roller coaster.

In India in February this year, the epidemic was in a law.

Largely unnoticed, the Delta variant was about to change that.

While the variant was just taking off, people were really carrying on their normal lives,

behaviour had indeed almost turned back to pre-pandemic ways of living.

And so what that meant was that the virus was really starting to spread almost silently,

but very, very rapidly.

It wasn't until there was an explosion of cases, it really just first appeared in terms

of the demands on hospital places that the severity of this new variant was really well understood.

The precipitous rise in cases in India in April made it clear that this variant was going

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