A police officer was bitten by a protester at Auckland's northern boundary as a group blocked traffic for more than an hour.
About 50 protesters arrived from the northern side of the boundary on State Highway 1 at Te Hana.
Traffic in both directions was brought to a halt by the group and some of their vehicles.
Police said they attempted to engage with the group and a number of vehicles were towed in order to clear the roadway.
Officers physically intervened to move protesters off the road and in the process one was bitten by an "as yet unidentified protester", police said.
"Actions like this are totally avoidable and poses unnecessary risk to our staff who are simply trying do their part in preventing the spread of Covid-19," Waitematā District Commander Superintendent Naila Hassan said in a statement.
Protesters have dispersed and police will keep monitoring the site.
Protest interfering with vaccination efforts - Te Rūnanga ō Ngāti Whātua
Te Rūnanga ō Ngāti Whātua uri and chief operating officer Antony Thompson said trucks carrying food and medical supplies were being held up unnecessarily "creating major risks to our communities and whānau of the North".
He said thoughtless moves like this put whānau in danger and urged members of these groups to think about the impact they were having on those they believed they were trying to protect
Thompson said protesters were using this as an opportunity to "grandstand their issue".
Thompson told Morning Report the group arrived about 6am from the north and were stopped by police about 500m from the main checkpoint and were asked to move to the side of the road.
"A few of them parked their vehicles in the middle of the road to block the road and the traffic behind them.
"It escalated from there, police came on board and they de-escalated the situation. We were really happy with that.
"The protesters still wouldn't move so they were moved backwards and a few of their vehicles were towed."
Thompson said it got the way of vaccination efforts in the region, with people pulled off their work on mobile vaccination units to support border teams.
That was "hugely frustrating", he said.
"We've got kaitiaki that work on the border that also assist with vaccinations - because it's a large operation."
"This morning we pulled people in just to support our border team but that stops our vaccination programme " - Antony Thomson
He said a number of different groups and people were among the protesters.
As at about 8.30am traffic was clearing but still slow moving, Thompson said.