The virus that causes Covid-19 is "tricky" and will be with us for "a very long period of time" says a medical researcher.
As the government weighs up where New Zealand needs to go in terms of its Covid-19 settings, the Malaghan Institute of Medical Research says researchers here and across the world are still "very concerned with trying to develop safe, effective and long-lasting vaccines".
The institute's director of strategic partnerships, Kjesten Wiig, told Morning Report research had shown no-one had 100 percent protection from the virus, as it continued to mutate.
"It's a tricky little virus; I think it's going to be with us for a very long period of time," Dr Wiig said.
"What we're seeing internationally, and even here in New Zealand, is that people are catching the virus two, three, even four times as the new variants roll through."
She said researchers both here and across the world were therefore still "very concerned with trying to develop safe, effective and long-lasting vaccines".
The Malaghan Institute, which brings together relevant academic institutions as well as the private sector, is currently working on two lead vaccine candidates - a spike protein booster vaccine developed locally and a pan Covid-19 vaccine, developed as part of a Trans-Tasman collaboration.
"We're in ... the late stages of development for our protein cell unit vaccine, which is the one that we do here in New Zealand, our Kiwi vaccine, Wiig said.
"We'll have our safety data probably by the end of this year, which will mean that we'll be able to go into humans to test that clinically next year."
Developing vaccines to clinical trial stage was an expensive and time-consuming process, she said.
"In order to get into the clinic you have to have a lot of data to show that there's reason to go into humans and that it's expected to be very safe and effective, and then once you get into the human testing, that's ... number of years' worth of safety and efficacy testing there as well."
A previous clinical study carried out by the Vaccine Alliance Aotearoa New Zealand (VAANZ), of which the institute is a part, found that New Zealanders broadly showed a strong immune response to the Pfizer-BioNTech vaccine which was rolled out as part of the country's pandemic response.
However some groups were found to have a less-robust immune response.
"What we found was that people responded very similar to what had been observed internationally, but we did see that the more vulnerable groups - so older people, diabetic, Māori and Pasifika - show they have a less-robust response than others," Wiig said.
"That just highlights the need for protection in these groups."