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

OnlyFans is an online platform where people create content (photos, videos and live streams), which can be monetised. Although it hosts a variety of content across topics like fitness and cooking, OnlyFans is known widely for hosting adult content, much of it explicit. As its popularity has soared, so too has the controversy and stigma surrounding the platform. Last week, Kurts Adams Rozentals, a world-class British canoeist, revealed that he had been banned from competing by Paddle UK — the sport’s governing body — after they learned he was an OnlyFans content creator. He told the BBC he started posting content because Paddle UK’s annual grant of £16,000 was insufficient to cover rent, travel, food and other expenses associated with full-time training in London.

BBC Business Reporter Charlotte Edwards explains exactly how the platform works and who owns it. She also gives us the latest on the embattled British canoer. Plus: Chimgozirim Nwokoma, a senior reporter for Tech Point Africa, tells us about All Access Fans — an African start-up that have taken inspiration from OnlyFans’ subscription-based business model — and the reaction to it.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 0330 12 33 22 6 Presenter: Hannah Gelbart Producers: William Lee Adams and Benita Barden Editor: Verity Wilde

High school prom may have started off as an American tradition, but now, it’s spread across the globe. In Uganda, proms are often a super lavish event, with couples flying in on helicopters or pulling up in expensive cars, before doing multiple outfit changes through the night. But the government says it’s gone too far — and it’s brought in new rules to curb the celebrations. Uganda’s Ministry of Education has banned what it calls “indecent dressing” and has even introduced a 6PM curfew, arguing that extravagant prom parties put unnecessary financial pressure on parents.

Gloria Achieng, a BBC reporter in Kenya, tells us more about Uganda’s prom culture and what these new rules mean for students. We hear from young people across Uganda, who share their thoughts on the ban with us. And we find out which member of the What in the World team is prom royalty. And how did prom culture start in America?

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: Hannah Gelbart Producers: Chelsea Coates, Emily Horler and Mora Morrison Editor: Verity Wilde

The Pyramids of Giza are among Egypt's most famous landmarks. The Great Pyramid is made up of 2.3 million stone blocks, weighing five million tonnes in total. For centuries no one has known precisely how they were built, or how the stones were transported.

Using radar satellite imagery, historical maps and geophysical surveys, a research team has mapped a long-lost, ancient branch of the River Nile - which they believe was buried by a major drought and sandstorms thousands of years ago. They think this waterway was used for the transportation of heavier blocks, equipment and people and finally explains how the Pyramids were constructed. So is this mystery finally wrapped up?

Rehab Ismail, a BBC journalist in Cairo, describes what it’s like to visit the Pyramids of Giza and explains what the Egyptian authorities are doing to preserve the area from over-tourism. Egyptologist Yossra Ibrahim tells us which mysteries have been solved and which still remain.

Archive courtesy of British Pathé.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: William Lee Adams Producers: Baldeep Chahal, Julia Ross-Roy and Abiona Boja Video Journalist: Baldeep Chahal Editor: Verity Wilde

In South Korea, what presidential candidates are wearing is a hot topic.

People use fashion to express themselves. Many of us think carefully about what we put on and how others will view our outfits, whether we choose an iconic hat or a monochrome look. But for politicians and their spouses, every look is carefully calculated to send a specific message.

South Korea is having a snap election which means that image consultants are quietly shaping the new public faces of leadership, from tie colours to jumpers to hairstyles. Yoon Suk Yeol was removed from office for putting the country under martial law for six hours in December. Polls have placed Lee Jae-myung of the main opposition Democratic Party as the frontrunner among six candidates, followed by Kim Moon-soo from the ruling PPP.

We chat with Rachel Lee from our team in Seoul - she’s been speaking to some of those image consultants about what they do. Also, Stacy Wasiche, a fashion blogger from Kenya, runs us through the latest political fashion trends and how it’s different depending on what country you look at.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: Hannah Gelbart Producers: Mora Morrison and Emily Horler Editor: Harriet Oliver

From Taylor Swift to Michael Jackson, there’s been countless superstar musicians who have called out their record labels for how much they’re being paid for their music. For musicians at the start of their careers it can be even more challenging to make money. The emergence of streaming sites like Spotify has made understanding publishing a bit more complicated. So how does it all really work?

BBC Newsbeat reporter Riyah Collins talks us through how musicians make their money - from royalties, touring and streaming. Mary Spender, a singer-songwriter here in the U.K. shares her experience with earning money from her music.

Plus we also hear from Kenyan TV host, KenRelBis, who’s launched a free music distribution platform to help local artists.

Instagram: @bbcwhatintheworld Email: whatintheworld@bbc.co.uk WhatsApp: +44 330 12 33 22 6 Presenter: Iqra Farooq Producers: Emily Horler and Maria Clara Montoya Video Journalist: Baldeep Chahal Editor: Verity Wilde