What went wrong with vaccinating the world?

The coronavirus pandemic has been slowed in developed countries thanks to massive vaccination drives. Countries have bought stocks to cover their populations, and in many cases have far more than they need.

However, poorer countries generally have failed to reserve, and buy the vaccine stock they need. Now the world is faced with a problem of re-distribution, and campaigners say that the answer is to force drug companies to share their secrets, in order to make manufacturing possible in any country in the world.

Three experts explain how we arrived at this point and the challenges now facing everyone involved in the fight against Covid-19.