What we know about the strain that triggered SA lockdown
The COVID-19 strain that escaped Peppers medi-hotel on Waymouth St and triggered a six-day lockdown across South Australia has an extremely short incubation period, with many infected showing no symptoms at all.
Chief Public Health Officer Professor Nicola Spurrier said when someone was exposed they became infectious within 24 hours or less, which was incredibly fast.
"The other characteristic of the cases we've seen so far is they've had minimal symptoms, and sometimes no symptoms, but have been able to pass it on to other people," Prof Spurrier said.
That characteristic meant that a generation, or stage of people passing on the virus to others, was only about three days.
SA was now at the virus's fifth generation but contact tracing had been done up to the fourth generation.
"We don't have any time to wait," Prof Spurrier said.
SA Health has confirmed the strain originated from an overseas case of an ex-pat in his 50s who travelled from Britain in early November. The cluster is now at 23 cases.
It comes as new research out of Melbourne shows children exposed to coronavirus from their infected parents have produced antibodies to the virus without testing positive.
It followed cases during the Melbourne lockdown where children had close contact with symptomatic infected parents but never got the virus.
The Murdoch Children's Research Institute found the children were producing an antibody in their saliva to produce an immune response.
The study suggest the antibodies may have stopped the virus from invading their system.
The institute is monitoring more than 20 families, including some in which parents were COVID-19 infected but their children weren't, to obtain more information on immunity in children.
Originally published as What we know about the COVID strain that triggered SA lockdown