World leaders pledged to end the AIDS pandemic as a public health threat by 2030. And the World Health Organisation aims to reduce HIV infections from 1.5 million in 2020 to 335,000 by 2030. The African continent still has the highest number of HIV infections globally.

How will cuts to the US government's main overseas aid agency, USAID, affect the treatment and prevention of HIV in Africa? And will it make it harder for countries to end new cases of HIV by 2030?

BBC Africa health correspondent Makuochi Okafor explains what HIV is and how it’s currently treated and prevented. He also breaks down some of the misinformation around HIV and PrEP (Pre-Exposure Prophylaxis) which stops HIV getting into your body. And we discuss what impact the cuts to USAID are having on HIV treatment and prevention programmes.

BBC journalist Nathalia Jimenez also gives us a brief guide to the cuts to USAID.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: Hannah Gelbart Producers: Julia Ross-Roy and Adam Chowdhury Video Journalist: Baldeep Chahal Editor: Verity Wilde

What do Billie Eilish, Doja Cat and Jennie from Blackpink have in common? They have all been spotted wearing Vietnamese fashion brands. You might have noticed that your clothes and shoes have labels saying ?Made in Vietnam?. The garment and textile industry in Vietnam is massive - it?s the second biggest exporter in the world, after China. And it employs three million people, most of them women. Global brands like Nike and Uniqlo make their clothes there.

But recently, Vietnamese brands are being celebrated in their own right and finding new fans. Thuong Le from the BBC Vietnamese Service talks to us about the Vietnamese fashion industry and why their brands are becoming so popular outside the country. What?s their appeal? Fashion influencer Joyce Ng from Singapore explains. Vietnamese fashion business consultant Quynh Nguyen, who works for the brand LSOUL, describes the impact foreign buyers have had on the industry. And Professor Kim Myung-hee from South Korea, a former stylist of Rain and Jun Ji-hyun, tells us why Vietnamese fashion isn?t just a short term trend.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: William Lee Adams Producers: Thuong Le, Julia Ross-Roy and Benita Barden Editor: Verity Wilde

Polar bears are the biggest bears in the world and the only marine bear. There are estimated to be around 26,000 globally. They’re mostly found in Canada, but also in Russia, the US, Norway and Greenland. Their main prey is seal, specifically seal blubber, as they need a diet high in fat to survive the freezing Arctic conditions.

Polar bears are great swimmers but they can’t outswim seals. So they hunt them on the Arctic sea ice, waiting for them to come up for air and then pouncing. But as the amount of sea ice decreases due to global warming, the polar bear populations that live in the more southerly, warmer parts of the Arctic are in decline.

BBC Science correspondent Victoria Gill explains what it’s like to see a polar bear up close and the challenges they’re facing. Alysa McCall, a scientist at Polar Bears International, gives us her top facts about polar bears and Arctic sea ice.

And we explore whether refreezing parts of the Arctic could be a realistic solution, with Kerry Nickols, from Ocean Visions, a non-profit organisation which looks at ways to protect and restore Arctic sea ice.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: Hannah Gelbart Producers: Julia Ross-Roy, Benita Barden and Thuong Le Video Journalist: Baldeep Chahal Editor: Verity Wilde