The great unknown: do Covid vaccines stop you spreading the virus?

We know vaccination is very effective in preventing serious illness, but whether it stops coronavirus transmission is another story

As Australia joins the worldwide Covid-19 vaccine rollout, researchers keep emphasising that while we know the various vaccines in use are strong at preventing hospitalisation and severe disease, it's less clear how well they stop the virus spreading to other people.

While the term Covid-19' is often used interchangeably to describe both the virus and the disease, it is important to understand the distinction between the two.