Hello, I'm Rosak Kins.

Each week on the BBC World Service, I look at one of the biggest issues in the news.

This time, it's COVID vaccines and sport.

The fact is that someone has prominent as him, bears responsibility for millions of people

who have not been vaccinated, who follow him and worship the ground he walks on.

Stephen Parnis is an emergency doctor in Melbourne, and as you've probably guessed,

he's talking about Novak Djokovic.

The men's tennis world number one flew in to defend his Australian open title,

but he also flew right into the centre of a debate about COVID vaccinations and sport.

To understand why, let's go back to a post on social media on the 4th of January.

The world tennis number one Novak Djokovic says he will go to Australia this month to defend

his open title, the Serbian star, who's spoken out against COVID vaccines, said on Instagram

that he'd received a medical exemption.

In other words, Djokovic would be allowed to play despite not meeting the tournament's

requirement for players to be fully vaccinated, and many Australians weren't happy about it.

You shouldn't be allowed to come. It's his choice not to be vaccinated, which is fine,

and I think the government here has made the choice that you know you should be vaccinated.

But as planned, Djokovic flew in, and things immediately got complicated.

He was detained at the airport, his visa was cancelled, and he was moved to an immigration

detention hotel. On social media, he became known as Novak Djokovic.

The BBC Sydney correspondent Shima Cleal explains why this issue is so sensitive.

Granting a world famous athlete, an exemption from the vaccine, was never really going to go

...