A New Zealand man has been labeled "unbelievably selfish" after he received up to 10 COVID-19 vaccines in one day.

The news website Stuff said the man, who has not been named and is now under investigation, visited several vaccination centers.

Local media reported that he was paid to take the shots on behalf of other people, pretending to be the individuals who had allegedly hired him.

The country's Ministry of Health was taking the matter seriously, COVID-19 vaccine and immunization program manager Astrid Koornneef told Stuff.

"We are very concerned about this situation and are working with the appropriate agencies," she said.

Lives put at risk

"To assume another person's identity and receive a medical treatment is dangerous," Koornneef was cited by the New Zealand Herald as saying. "This puts at risk the person who receives a vaccination under an assumed identity and the person whose health record will show they have been vaccinated when they have not."

The ministry would not say where the incidents took place but advised the man to visit a doctor for advice as soon as possible.

University of Auckland vaccinologist Helen Petousis-Harris told Stuff that studies did not cover such excessive doses so it was difficult to predict what might happen to someone who had 10 vaccines in a single day.

Petousis-Harris said the man was likely to feel rough for a day or two as his body mounts an immune response to the multiple vaccines. "It’s unbelievably selfish," she added.

Malaghan Institute director and immunologist Graham Le Gros said the actions were "silly and dangerous."

Man 'unlikely to die'

He added that the man was unlikely to die from 10 jabs, but having so many doses could mean the vaccine doesn’t work as well.

Le Gros said those who receive vaccines on behalf of other people are "not making themselves safer, and they're certainly foolish by aiding people who need to be made safe."

In New Zealand, people do not have to show identification when receiving the vaccine.

The country dropped its zero-COVID strategy in October after infections spiked.

The government was widely praised for a very low infection rate for most of the pandemic. Vaccinated visitors will be welcomed again from April.

Many of the country's businesses and facilities use a domestic vaccination certificate that only allows fully vaccinated people access to places.

With a population of 5 million, the country has reported about 12,500 cases and 46 deaths since the onset of the pandemic.

About 89% of residents are fully vaccinated.

With material from Agence France-Presse.