Auckland epidemiologist Rod Jackson is urging New Zealanders to take Omicron seriously, and certainly not to think of it as similar to the flu.
The warning comes as new modelling shows Omicron could peak by mid next month with about 4000 daily cases.
Jackson told Morning Report there was "no doubt" New Zealanders were not taking Omicron seriously.
"The standard thing I hear these days is 'Oh this is just a mild condition, it's like a mild flu', and it's just not true.
"In the (United) States, for example, more people have died from Omicron, than died from Delta. It's also worth noting that I mean if you ever had a bad flu, you feel like you want to die.
"It's not a particularly good comparison. The flu kills 500 people a year. Normally that's almost double the road crash death rate. It's about the same as suicide, just a bit less.
"This is a serious disease that people need to take seriously."
The high Omicron death rate in the US was because the variant was so contagious, Jackson said.
"There's a couple of things we really need to do - get maximally vaccinated and wear a good mask" - Auckland epidemiologist Rod Jackson
"It spreads like wildfire, and I guess that's the other important issue when we're thinking about the comparison between the flu and and Omicron is that the R value, the number of people that one infected person with the flu is going to infect, is less than two.
"With Omicron, we don't even know how big it is. It's certainly much bigger than Delta, which was about six (people infected per person), so this is a very different disease from the flu and we need to take it seriously.
"We need to go out and get maximally vaccinated."
On that point, Jackson said there were a likely a lot of reasons more people had not got a booster shot.
"One is, we're all a little over it, aren't we? Everyone is tired. Everyone wants to go back to normal.
"Secondly there is this general view is that I hear - 'Oh but isn't Omicron, you know, just like a cold?'
"For some people, it's very mild. For some people it's asymptomatic, but people die of this.
"Look at the hospital rates. Every New Zealander should have a look at the graph of the number of hospitalisations, and if you look at it in the last week or two, it's going almost vertically.
"There's a couple of things we really need to do - get maximally vaccinated and wear a good mask."
Yesterday, the Ministry of Health reported 2846 Covid-19 cases in the community and 143 people in hospital with the virus, including one in intensive care.