In Wuhan, they're partying like it's 2019. The nightclub's bars and restaurants are all packed.

But Britain begins 2021 in the grip of its worst national emergency since World War II.

Tens of thousands are dead, hospitals are overwhelmed and they're running out of oxygen.

The population is under lockdown and the economy is in crisis. How did this happen?

As thousands celebrate New Year's Eve in the end of 2019 in cities across Britain,

our prime minister sunbathe is in the Caribbean resort of Mystique.

The Times newspaper splashes on Britain's season New Year on a wave of optimism.

Buried in the news is an unnerving story. China reports a mysterious cluster of pneumonia

with 27 stricken, most of whom had visited a seafood market in Wuhan.

In the coming days and weeks, people begin to die and cases spread to Japan, South Korea,

Thailand and the United States. Two years ago, Professor Devi Sridhar warned of a pandemic caused

by a virus jumping from animals to humans. On 16 January 2020, she warns on Twitter that the

outbreak needed to be taken seriously because of cross-border spread, planes mean bugs travel far

in fast, likely human to human transmission, and previous outbreaks of torque over responding

is better than delaying action. As public health England moves the risk level to the British

public from very low to low, Wuhan is closed off. China's authorities place it under lockdown.

This is the clearest sign yet to the world, that this illness is very, very serious.

Residents are sealed in their own homes. Seventeen are now dead.

It's the 22nd of January, and as the Sunday Times's Insight team reports,

the scientific advisory meeting for emergencies, or sage, meets. It's chaired by chief

scientific advisor, Sir Patrick Valance, and chief medical advisor, Professor Chris Whitty.

Those present here that Chinese scientists are warning that the virus is very infectious.

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