A Sydney traveller to Wellington receiving a first dose of the COVID-19 vaccine may be to thank for potentially saving New Zealand from another outbreak, a virus expert says.
Last week, greater Wellington moved to alert level 2 when a Sydney tourist, who'd received one dose of the AstraZeneca vaccine, tested positive for COVID-19 after returning from a trip to the capital - with officials believing he caught the virus before arriving in Wellington.
No cases of COVID-19 have been reported in the Wellington community since the traveller, later confirmed to have the highly contagious Delta variant first identified in India, tested positive early last week. Restrictions are due to be lifted in the capital on Tuesday.
Shaun Hendy, a COVID-19 modelling expert, says New Zealand has been fortunate with the latest scare.
"The virus follows the '80/20 rule' and that means that only about one in five people go on to create most of the spread," Prof Hendy told The AM Show on Tuesday. "In this case, it looks like we've got lucky.
"He'd had the first dose of the vaccine and that may have helped stop transmission."
Experts have said global uptake and distribution of COVID-19 vaccines is crucial to returning to normality. Prof Hendy noted the sooner people get vaccinated, the less chance there is for COVID-19 to evolve and mutate.
"It is changing because it's had so much opportunity to infect people - it's tweaking its method of getting into cells."
Across the Tasman, five of Australia's eight states and territories have been hit by outbreaks of the Delta variant - with Sydney beginning a two-week lockdown at the weekend. Officials have since made it mandatory for rest home and quarantine workers to get vaccinated.
"The Delta variant is presenting very different challenges from those we have faced in the past," Australia Prime Minister Scott Morrison said on Monday.
Eighteen new local cases were reported in New South Wales on Monday, compared with 30 a day earlier, taking the total infections in the latest outbreak to 130 since the first case was detected nearly two weeks ago in a driver for overseas airline crews.
The state has been told, "to be prepared for the numbers to go up considerably".
Australia has registered 30,500 COVID-19 cases and 910 deaths while New Zealand has recorded 2382 infections and 26 deaths.
Vaccine rollouts on both sides of the Tasman, however, have been slow.
Quarantine-free travel between New Zealand and Australia remains paused.
Reuters / Newshub.