The head of managed isolation and quarantine facilities has made more changes to the exercise bus system, after failures onboard a bus from the Grand Mecure Hotel.

Frustrated public health experts have been calling on the government for tighter restrictions at the border and MIQ facilities.

Since July 2019, there have been 13 border control oversights, one which resulted in a cluster of 179 cases.

The most recent was last week, where returnees on an exercise bus mingled between bubbles, had no face masks on and had people from low and high-risk countries switching seats.

Late on Tuesday evening, the head of MIQ revealed changes have been made.

Brigadier Jim Bliss says they will now be using two-door buses.

The driver must use the front door, and returnees would enter and exit from the back.

There will also now be a verbal briefing at the beginning of each journey about wearing masks "correctly" at all times and sitting in the same seat to and from the exercise area.

"In addition, hard-plastic screens are now in place behind the driver's seat to separate the drivers and returnees," Bliss says.

Drivers will also have to wear the more protective N95 masks.

Experts have been calling on the government to tighten restrictions at the border for months, and want exercise buses to be removed completely.

University of Otago professor of public health Nick Wilson says enough is enough.

"We can see from a public health perspective it is possible to do things very much better but what we're seeing here is potentially some complacency by the government," says Prof Wilson.

"It's done a great job with vaccinating border workers but it's not thinking about all the other problems seriously enough and that's why we continue to have problems."

There are two new cases at the border on Tuesday - both from the same flight as 10 others who tested positive upon arrival on Monday.

Prof Wilson says that suggests the pre-departure testing system is not working and red zone countries should be suspended from entering, while allegations about fake negative results are investigated.

The government should prioritise a bubble with Australia over the risk posed by Covid-19-riddled countries, he says.

"The economic benefits of an effective trans-Tasman green zone are very large, it might be a reasonable trade off to focus on that successful arrangement and turn down the tap of all these infected people coming in from the US, UK and India. The risks are enormously great with one group of countries and very low with Australia. So it seems like we've got the balance wrong."

Prof Wilson says high-risk returnees could spread the virus on the plane, among other returnees and potentially infect frontline staff.

National Party Covid-19 spokesperson Chris Bishop says restrictions for red zone returnees needs to be escalated.

"I don't think they should stop people from high-risk countries coming in, but the protocols around those passengers need to be better.

"We've been saying for some months now that there should be dedicated hotels for high-risk passengers. That hasn't happened.

"And instead, we still hear stories of mixing and mingling on things like buses and the common areas of the hotels."

Bishop could not believe exercise bus trips are being allowed to resume.

Prof Wilson says small changes could make a big difference to the country's risk.

"We need to reduce the number of infected people coming from high-risk red zone countries, we need to look at vaccinating people potentially when they arrive in New Zealand.

"We need to look at moving MIQ facilities out of the cities, eliminate shared spaces and exercise areas and smoking areas - they need to be removed."

He says daily saliva testing of border staff and returnees is another good option and the cost of implementing the changes is worth the investment.

This month, Director-General of Health Ashley Bloomfield says saliva testing is being trialled in quarantine facilities.

Vaccines

The February outbreak was most likely linked to the border and heavily impacted the South Auckland community.

It's hoped vaccinations of border and MIQ workers will lessen the chance of a border breach.

So far, more than 40,000 have had their first jab.

As the next phase of the roll-out begins, Immunisation Advisory Centre director Nikki Turner says she would like to see an increase in targeted messaging about vaccinations to vulnerable communities.

"What I'd like to see the New Zealand government do is to really ramp up the communication, the science, the messages to all our different communities, particularly those who have traditionally missed out.

"So I really want to see that our Māori communities, our Pasifika communities, elderly rest home and residential care, really get to hear the messages."

She says the government should be focusing on groups of people rather than meeting a vaccination or herd immunity percentage.

Anyone calling the Covid-19 Healthline can speak with someone in their own language, with access to interpreters for over 150 languages, including te reo Māori and the nine main Pacific languages.

A Ministry of Health spokesperson previously said Māori and Pacific providers hold trusted relationships with the whānau they serve and play a crucial role to maximise uptake and achieve equity.

Associate Minister of Health Aupito William Sio has also held online meetings with Pacific leaders and groups about the vaccine.

Deputy Director-General of Māori Health John Whaanga previously said they would be working hard to ensure everyone had a chance to get accurate information.

"There will be more than one opportunity to be trying to influence people. It is really important that we don't see, I think, anybody as a lost cause. We're really interested in making sure that we get the best information out.

"It's our intention to take a comprehensive approach and to leave no stone unturned in terms of providing good information and opportunities for people to be vaccinated."

-RNZ/Charlotte Cook.