Close contacts of people with COVID in New South Wales and Victoria will soon no longer have to be in isolation for seven days. Other states and territories, including Queensland and the Australian Capital Territory, are considering or likely to announce similar measures.
In NSW from 6pm tomorrow and in Victoria from just before midnight tomorrow, close contacts of COVID cases will no longer need to be isolated at home as long as they test negative for COVID, and follow other rules designed to limit the spread of the virus. to limit.
The move frees up close contacts to return to work outside the home, but carries a slightly increased risk of the virus spreading to the wider community. However, not everyone agrees on whether even this small risk is worth taking.
So what is the risk of a domestic contact contracting COVID? And what else can we do to minimize the risk to the wider community after isolation rules are relaxed?
Read more: Many places are starting to roll back COVID restrictions, but it doesn’t mean the pandemic is over yet
What is changing?
The upcoming changes in NSW and Victoria only address the isolation requirements of close contacts. People with COVID have to be in isolation for another seven days.
Details of what this means for close contacts in NSW or Victoria differ slightly. However, governments wisely ask close contacts to take some measures to reduce the risk of them infecting other people. Including:
work from home where possible
tell their employer that they are a close contact
wear a mask indoors when they are outdoors
taking multiple rapid antigen tests over seven days
avoiding contact with immunocompromised and elderly people
avoiding vulnerable settings such as residential aged care or hospitals
These will further reduce the already low risk of transmitting the virus.
Read more: Time to lift vaccine mandates? Not so fast – it could have unintended consequences
These changes come after much lobbying by corporate groups and some unions who say their members are struggling with so many employees who don’t have COVID, or because they are in close contact with someone who is infected.
We have also seen schools, airports and other sectors struggle to find workers.
The changes also follow the relaxation of close contact isolation requirements made in January for several categories of essential workers, such as emergency and childcare workers.
Read more: The latest isolation rules for critical workers strike the right balance. But that’s not the end of the story
So many of us are immune
All states and territories are now past the second Omicron peak, caused by the BA.2 subvariant. Western Australia has never had the BA.1 wave due to closed borders, and is now also comes from the peak of its BA.2 wave.
With about 50,000 cases diagnosed each day, Australia is still in the throes of a massive outbreak, and the true number of daily cases is likely several times this.
This is because the rate of asymptomatic infections is estimated to be 25-54%, so many people wouldn’t think of getting tested. Not everyone who feels unwell is tested. And even if people test positive with a rapid antigen test, not everyone will report it to authorities.
So the majority of people in the community have either natural immunity to infection, vaccine-induced immunity, or both (hybrid immunity). It is therefore high time to ask whether insulation is still essential for close contacts.
What is the real risk at home?
If you live in a household with someone who is infected, what is your risk of contracting the BA.2 subvariant of Omicron, which is dominant in Australia?
Despite the fact that it is highly contagious, there appears to be only a 13% chance that you will become infected. So the risk is actually quite small.
Read more: BA.2 is like Omicron’s sister. Here’s what we know about it so far
What about the risk to the wider community?
At the moment, about 20% of PCR tests in Australia are positive in a single day, indicating a huge amount of infection in the community, much of it undiagnosed.
However, due to the high level of immunity in the population and the relatively low contribution of the close contact rule changes to transmission risk, I do not believe the changes will have a major impact on the number of cases. The changes will also be a big relief for business.
What should happen next?
To prevent these changes from driving up the number of cases, we must assume that close contacts are doing the right thing – masking, avoiding contact with vulnerable people outdoors and testing themselves regularly. Let’s hope this happens.
Finally, daily rapid antigen tests (under certain circumstances) for close contacts will be expensive. Imagine a family of five where one person is infected. That’s up to 28 rapid antigen tests for the four close contacts, for about A$10 per test.
Currently, only concession card holders receive a free limited supply of rapid antigen testing. So governments will have to seriously think about some kind of subsidy for close contacts, or better yet, provide it for free.
Author: Adrian Esterman – Professor of Biostatistics and Epidemiology, University of South Australia