Infection raises question of how

AUCKLAND: Two vital questions hang over the case of a fully vaccinated border worker who has tested positive for Covid19, a leading epidemiologist says.

Yesterday’s new case, which came on day two of the transtasman bubble, is the second Auckland Airport cleaner to be infected through their work.

The new case worked cleaning planes from highrisk countries and had received both vaccine jabs.

The earlier case was an LSG Sky Chefs worker who is believed to be the index case of the Valentine’s Day Papatoetoe cluster earlier in the year which infected 15 people.

Three new locations of interest have been identified relating to the latest case, including the food court at Westfield St Lukes mall, in Auckland.

Both the Australian and New Zealand Governments stressed yesterday that new cases of the virus were expected and the latest infection did not threaten the transtasman travel bubble.

University of Otago epidemiologist Prof Michael Baker said two huge questions hung over the new Covid19 case: how the person became infected — given that they had been fully vaccinated — and what the mode of infection was.

‘‘This case is very interesting in a lot of respects — the fact that they were only found on routine testing, they didn’t have symptoms, they were vaccinated.

‘‘It’s quite likely that they may have had a very low . . . risk of infecting other people in those circumstances.

‘‘This is right at the core of one of the great questions of vaccination, does it prevent you from transmitting the virus?

‘‘Obviously, in this person’s case, it didn’t stop them from getting infected.

‘‘It might be that their viral load remained very low, and their risk of infecting other people very small.

‘‘That’s what we’re hoping the vaccine does.’’

Prof Baker said the new case raised the possibility of the virus being transmitted on a surface or aerosols.

‘‘Aerosols can linger in the air for some time after an infected person has left an area.

‘‘I don’t think that has ever been documented, that someone has ever been infected from an aerosol after passengers have disembarked [the aircraft].

He said genome sequencing was critical as it would confirm if the new case’s infection matched any other known genomes that had come through the border at that time.

Prof Baker did not think the case threatened transtasman quarantinefree travel.

There were two new cases of Covid19 reported in managed quarantine facilities yesterday. — The New Zealand Herald