Mr Simes says life won't be much different during level 3, so don't expect to throw a party, or return to what life used to be like before the onset on Covid-19.
"It's important to remember that this is a long-term battle and people will still be expected to adhere to self-isolation rules," says Mr Simes.
"Returning to a normal social life could potentially allow the virus to spread.
"To undo all the work we have put into trying to contain this virus would be a tragedy if people continued to flout the rules.
"The main messages will remain the same – stay at home and save lives."
The criteria for determining a move to level 3 was spelt out by Prime Minister Jacinda Arden yesterday.
Factors include knowing community transmission is under control, the transmission rate is very low, there are robust measures at the border stopping new infection, tracing and testing capacity to shut down any new outbreak, and capacity in the health system.
The full breakdown of alert level 3 is available at covid19.govt.nz