Oliver Conway

More than 20 million people around the world are considered to be at high risk of contracting HIV. A drug in the form of a daily pill can prevent it, but only about 3.5 million people take it. Now, researchers are hoping that a yearly injection can be a game-changer in the fight against the virus.

More than 20 million people around the world are considered to be at high risk of contracting HIV. A drug in the form of a daily pill can prevent it, but only about 3.5 million people take it. Now, researchers are hoping that a yearly injection can be a game-changer in the fight against the virus.

And it's just passed an important safety trial, as I heard from our health correspondent Dominic Hughes.

And it's just passed an important safety trial, as I heard from our health correspondent Dominic Hughes.

And so what's the next stage in working out whether this injection can be rolled out around the world?

And so what's the next stage in working out whether this injection can be rolled out around the world?

And how long might that take?

And how long might that take?

Dominic Hughes, our health correspondent. President Trump has dropped his threat to step up his trade war with Canada after he said he would double the tariff on steel and aluminium. The White House says the proposed 50% duty will not now take effect. The change of heart came after the Canadian province of Ontario decided not to impose a planned 25% surcharge on its electricity exports to the US.

Dominic Hughes, our health correspondent. President Trump has dropped his threat to step up his trade war with Canada after he said he would double the tariff on steel and aluminium. The White House says the proposed 50% duty will not now take effect. The change of heart came after the Canadian province of Ontario decided not to impose a planned 25% surcharge on its electricity exports to the US.

President Trump told reporters he respected the decision by Ontario's Premier, Doug Ford. Our North America business correspondent Erin Delmore has more details.

President Trump told reporters he respected the decision by Ontario's Premier, Doug Ford. Our North America business correspondent Erin Delmore has more details.

Erin Delmo. It's not unusual for people to like different music to their parents. It turns out that the same is sort of true for birds. A major study of one of the most common species, the great tit, has found that over time the tunes they sing change. The BBC's Evan Davis found out more from Professor Ben Sheldon of Oxford University.

Erin Delmo. It's not unusual for people to like different music to their parents. It turns out that the same is sort of true for birds. A major study of one of the most common species, the great tit, has found that over time the tunes they sing change. The BBC's Evan Davis found out more from Professor Ben Sheldon of Oxford University.

Ben Sheldon of Oxford University. Now, have you heard of space weather? We're planning a collaboration with our colleagues from BBC Weather about just that phenomenon, and we need your help. To explain more, I caught up with our lead weather presenter, Simon King.

Ben Sheldon of Oxford University. Now, have you heard of space weather? We're planning a collaboration with our colleagues from BBC Weather about just that phenomenon, and we need your help. To explain more, I caught up with our lead weather presenter, Simon King.

And as you look at the sun, it's getting quite busy at the moment.

And as you look at the sun, it's getting quite busy at the moment.

Talking about looking up to the sky, you also keep across meteor showers and eclipses, even though they're not strictly included in the definition of space weather.

Talking about looking up to the sky, you also keep across meteor showers and eclipses, even though they're not strictly included in the definition of space weather.