Australia shares ease as latest COVID-19 cluster dampens vaccine euphoria

* Energy index slips 1.3% to drag index lower

* Insurance firms drop as court rules for insurers in test case

* Bluescope Steel is top gainer in ASX200 on hiking earnings view

Nov 19 (Reuters) - Australian shares slipped on Thursday, as a fresh cluster of COVID-19 cases sparked a lockdown in the state of South Australia while numbers in the United States also soared, denting recent optimism over promising vaccine trial results.

The S&P/ASX 200 index fell 0.3% to 6,512.70 by around 0026 GMT. The benchmark closed 0.5% higher on Wednesday.

Most businesses in South Australia will close except for some food outlets, and people will be largely confined to their homes, as the state tries to avoid a more severe breakout like the one that all but shuttered neighbouring Victoria for more than 100 days.

“The outbreak of COVID-19 in South Australia has unsurprisingly generated considerable concern given it happened so quickly and after a number of months without any locally acquired transmission,” analysts at ANZ wrote.

“Google searches for “COVID testing” in South Australia have surged. The per capita level of searching is exceeding that of Victoria during its peak,” the analysts said.

U.S. drugmaker Pfizer said its COVID-19 vaccine was 95% effective and that it would apply for emergency U.S. authorization within days, but that did little to support markets.

Energy stocks fell, with sector heavyweight Woodside Petroleum losing as much as 1% while Santos shed 1.2%.

Top insurer QBE Insurance Group fell 5.6% while Suncorp Group shed 4.7% after a New South Wales court ruled against insurers in a business interruption test case on the pandemic’s impact heard last month.

Shares of the country’s second-largest insurer Insurance Australia Group were on a trading halt pending an announcement in response to the case.

Bucking the trend, Bluescope Steel was the top ASX 200 gainer with a 6.2% rise after the steelmaker raised earnings outlook and forecast a recovery in demand from key markets.

New Zealand’s benchmark S&P/NZX 50 index fell 0.3%, with dairy company a2 Milk Company down most with a 2.5% loss.

Reporting by Rashmi Ashok in Bengaluru, Editing by Sherry Jacob-Phillips