A mere second of close contact is all it might have taken for a plane cleaner in Auckland to catch COVID-19 despite wearing PPE being fully vaccinated, an epidemiologist says.
New Zealand authorities are desperately trying to figure out how the cleaner at Auckland International Airport came to test positive for the virus on Monday, the same day the long-awaited trans-Tasman bubble finally opened.
So far, officials have confirmed the worker, who wore full PPE, cleaned planes bound for Australia as well as those from “red zone” countries where COVID infection is considered widespread.
It is not yet clear whether she had any person-to-person contact with passengers, however genome sequencing has linked the case to an infected traveller from Ethiopia via Dubai who went into hotel quarantine after arriving in New Zealand on April 10.
Both genomes match the variant known as the highly infectious UK strain.
The worker, who is now in isolation, had received her full course of the Pfizer vaccine.
Epidemiologist Michael Baker from Otago University said the infection seemed to happen despite them having done “all the right things”.
“It’s a huge challenge to figure out how they got infected because they were doing all the right things with PPE and being vaccinated,” Prof Baker told the New Zealand Herald.
He said the worker might have brushed past the infected passenger in the plane aisle or on an air bridge connecting the plane to the terminal.
Prof Baker suggested arriving international aircraft should be left to sit empty for longer before workers boarded to clean them.
“I’m not aware of any recorded examples of aerosols being left in an environment and then infecting someone after a significant delay, so that may just be the change that’s needed,” he said.
New Zealand authorities named three Auckland venues as locations of interest visited by the worker on the weekend, however no new infections have been reported following the new case.
She worked three shifts during the infectious period, so far seven of her 17 close workplace contacts have returned negative results. One is being followed up and the others are yet to be tested, the Herald reported.
None of the woman’s household contacts have tested positive.
Yesterday, authorities sought to quell alarm over the positive case on the same day about 1800 travellers from Australia arrived in New Zealand without having to quarantine, as well as concerns about the worker having been fully vaccinated.
New Zealand Prime Minister Jacinda Ardern said health experts “entirely expected” people who were vaccinated to contract the virus, and the Pfizer vaccine was 95 per cent effective at reducing the severity of symptoms.
“This is not a worker who is very unwell,” Ms Ardern said.
“In this case this is working as intended … it’s doing its job, it doesn’t mean people won’t get it. It reduces the likelihood you pass it onto others.
“Previously … we couldn’t guarantee that workers wouldn’t be hospitalised or worse yet, that they wouldn’t die. The vaccine is saving lives.”