Infectious diseases expert Professor Michael Baker says he is optimistic there will be a Covid-19 vaccine within a year.
However, the epidemiologist says the vaccine might only be short-lived and people could be required to get a new shot every year, like the flu vaccine.
Speaking to Simon Barnett and Phil Gifford Afternoons on Newstalk ZB, Baker also took aim at people saying Covid-19 isn't as bad as the flu.
"Influenza typically kills about 500 people every winter in New Zealand, this [Covid-19] would be 15,000 dying in one year," he said.
"And that's how it's playing out around the globe at the moment. It still has the potential to kill 20 million across the globe in the next two years.
"It really is a very severe threat; the people who survive, many of them actually have severe long-term effects, so this is not a minor pandemic at all."
However, there is currently evidence a vaccine will work for most people for "at least some time" which Baker is excited about.
"The vaccine is still very encouraging and I'd be fairly optimistic that within a year we have a vaccine that at least helps somewhat," he said.
It comes after five new cases of Covid-19 were announced in New Zealand today, as well as a potential "mini-cluster".
There are three new community cases, one of which is under investigation.
Auckland is in alert level 3 until 11.59pm on Sunday, when it will move to a tighter level 2 alongside the rest of the country.
QR codes will be mandatory on most forms of public transport from Monday, the same day it will be compulsory to wear face masks on public transport.
Health Minister Chris Hipkins said today the actions will provide an extra layer of assurance and speed for contact tracing in the future.
Elsewhere, Baker said if everyone wore face masks on flights, then airlines could sell every seat and social distancing wouldn't be required.
"I think at level 2 it's a very reasonable approach to fill up those empty seats and that is one of the benefits of wearing masks," he said.
"Social distancing is still very important but the reason we have it is to avoid sharing our respiratory droplets … that's how the virus gets from one person to another.
"If everyone is wearing masks the whole time, I think the evidence is pretty strong that you can fill up buses and planes and so on."
Asked whether homemade masks were safe, Baker said something is better than nothing and recommended people use fabric masks.
He encouraged people to use reusable fabric masks because they were cheaper in the long run and they don't produce the same amount of waste as single-use masks.