Chief Health Officer Jeannette Young seemed almost incredulous on Thursday as she said efforts to suppress the spread of the highly transmissible Delta variant had surpassed expectations.

"I didn't expect we'd be so far in front of the virus," Dr Young told reporters, allowing herself a rare smile during the daily coronavirus briefing.

"It doesn't mean we're through it yet. We've still got a long way to go, but we have done really, really, really well until now."

She expressed hope the lockdown would lift as planned, at 4pm on Sunday, returning a sense of freedom to millions of people in the southeast corner.

"If we are able to get out of this on Sunday, it'll be the quickest response to a cluster of this size anywhere," Dr Young said.

Authorities are heartened by the lack of any mystery cases.

All of the 16 new locally acquired cases reported on Thursday have been directly linked to the cluster centred on schools at Indooroopilly, Spring Hill and St Lucia, on the northern side of the Brisbane River.

Of those, 12 were in isolation for the entirety of their infectious period, with the other four active in the community for either one or two days while infectious.

The lockdown conditions mean the four who were out and about while infectious, on July 30 and 31, would have encountered far fewer people.

Thursday's new cases included three linked to Ironside State School, nine household contacts of those cases, one teacher and two students at Brisbane Grammar, and a household contact of those students.

Deputy Premier Steven Miles batted away questions about whether there'd be extra support for businesses if the lockdown went beyond Sunday, saying it was too early to talk about that.

Business groups have been pushing more assistance and the opposition has said the government's $260 million support package for small and medium-sized businesses is woefully inadequate.

That was before Dr Young began telling Queenslanders to avoid online shopping for anything but essential supplies because that would see more delivery drivers moving around the southeast, possibly taking the virus with them.

"The least amount of movement in our community that we can possibly manage, the better," Dr Young again told consumers on Thursday.

The state's list of exposure sites includes locations in southeast, central and far north Queensland. New Brisbane sites include the Gallery of Modern Art and the Brisbane Wheel at South Bank.

At neighbouring West End, police spent Thursday morning doing drive-by checks of a long line of customers waiting at acclaimed croissanterie Lune on the opening day of its first Queensland store.

For two straight days more than 50,000 Queenslanders have turned out to be tested, something Mr Miles said must continue if Dr Young is to have the confidence to lift the lockdown.

"That level of testing ... gives the chief health officer a chance to be confident that there isn't transmission other than what we've been able to identify."

On the vaccination front, the federal government has fast-tracked the delivery of 112,320 Pfizer doses which will now arrive this month instead of next, and the state government is releasing 22,000 doses of AstraZeneca to pharmacies.

Brisbane City Council is doing its bit to boost vaccination rates, saying its 8000 workers will be paid for the time it takes to go and get a shot.

Another 11 cases of COVID-19 acquired overseas were also reported on Thursday. All are workers on an LNG tanker off Gladstone and will be managed on the ship unless their conditions change.

A total of 79 cases are now associated with the Indooroopilly cluster.

Australian Associated Press