Delta variant of Covid: What you need to know

World Health Organisation adviser and epidemiology professor at the University of New South Wales Mary-Louise McLaws says the Delta variant of Covid-19 is incredibly infectious.

• This story was first published by RNZ

That does not mean catching it from a fleeting exposure to a person you pass in the corridor, but rather a person infected with Delta pushes out a lot of small, light particles which hang in the air.

When someone walks through these particles without a mask, they are at risk of becoming infected.

‘‘This strain has learnt to infect with fewer particles.’’

These particles can remain in the air for five to 10 minutes, or even longer indoors, she said.

‘‘If you’ve only had one [vaccine] dose, plus about 14 days, assume you’re not protected.

‘‘Once you have the second dose, you are protected.’’

Prof McLaws said the Pfizer vaccine offered good protection after both doses.