Australia’s most populous state is reporting the worst day of its outbreak of the coronavirus delta variant, with a record 262 new local infections and five deaths from COVID-19.

New South Wales state Premier Gladys Berejiklian said Thursday that four of the dead had not been vaccinated and that one had received a single dose of AstraZeneca in late May.

Australian authorities have urged people in Sydney not to wait the optimal 12 weeks before getting their second AstraZeneca dose.

AstraZeneca and Pfizer are the only vaccines available in Australia.

There have been 21 COVID-19 deaths in Sydney since the latest outbreak began in June. Sydney and surrounding cities have been locked down since June 26.

Only 20% of Australian adults had been fully vaccinated by Wednesday, according to government figures.