Hello and welcome to the Intelligence on Economist Radio. I'm your host, Jason Palmer.

Every weekday, we provide a fresh perspective on the events shaping your world.

Recent frenzies of trading around small fry stocks such as GameStop

have drawn attention to a practice that every generation of brokers and dabblers discovers,

predatory trading.

We look into how it works and why it's not going anywhere.

And stories about plastic in the oceans have abounded in recent years,

from vast garbage patches on the surface to tiny bits of it in the water.

But the stuff that makes it to the darkest depths researchers have learned

is actually being put to use.

First up, though, South Africa has halted its rollout of the Oxford AstraZeneca vaccine, just a week after the country received its first million doses.

It seems the vaccine offers limited protection against a new variant of the coronavirus that's now dominant in the country.

Salim Abdul Karim, co-chair of South Africa's Ministerial Advisory Committee on COVID-19,

spoke to a World Health Organization briefing yesterday.

We don't want to end up with a situation where we vaccinated a million people or two million

people, but a vaccine that may not be effective in preventing hospitalization and severe disease.

In total, more than 1.2 billion coronavirus vaccine doses have been allocated for the continent,

but it's not clear when all those

jabs will arrive. The longer any region remains unvaccinated, the greater the chance that more

variants arise. Vaccines, though, can be tweaked, and a formulation of the Oxford vaccine

targeted at the South African variant could be going into arms by autumn.

What scientists cannot address is the long-run damage to Africa,

...