Factbox - The key moments in how Australia's COVID-19 success soured

CANBERRA: Australia has been widely lauded for its success in curtailing the spread of COVID-19 and limiting deaths to fewer than 1,000.

But while other developed nations have pressed ahead with vaccinating a large portion of their population, fewer than 10% of Australians have been fully vaccinated so far and Sydney is fighting its worst outbreak of the year.

Here are critical moments in Australia's vaccination programme.

August 2020:

Australia orders 54 million doses of AstraZeneca's COVID-19 vaccine, the vast majority of which will be manufactured locally. Critically, Australia only buys 20 million doses of Pfizer's COVID-19 vaccine, and the country does not have the ability to manufacture RNA vaccines, such as those made by Pfizer and Moderna.

January 2021:

Australia approves the use of the Pfizer vaccine, but warns supplies are limited.

February 2021:

Australia approves the use of AstraZeneca vaccine, with nearly 4 million doses scheduled to be imported from Europe.

February 2021:

Prime Minister Scott Morrison is vaccinated with the Pfizer vaccine, marking the start of Canberra's inoculation programme that is scheduled to be completed by October.

March 2021: The AstraZeneca vaccine begins to be manufactured in Australia. Initially doses are given to the elderly and people with underlying health issues.

April 2021:

Australia and the EU row amid issues over importing nearly 4 million doses of AstraZeneca vaccine, which Morrison says is responsible for delaying the government's inoculation programme.

April 2021:

Australia recommends people under 50 now receive the Pfizer vaccine after some cases of blood clots are reported in younger people who have received the AstraZeneca inoculation.

Australia doubles its order of Pfizer's COVID-19 vaccines, but these will not be supplied until late in 2021.

Morrison says Australia will now complete its COVID-19 vaccination programme by the end of the year.

May 2021: Australia orders 25 million doses of Moderna's COVID-19 vaccine, which are scheduled to arrive in Australia in the fourth quarter of 2021.

June 2021:

Australia recommends people under 60 can now receive the Pfizer vaccine after blood clot cases in some middle-aged people who had received the AstraZeneca vaccine. That shift means Canberra is effectively phasing out the use of the AstraZeneca vaccine that was to be the backbone of its inoculation programme.

June 2021:

Australia's most populous state records first locally acquired COVID-19 infections in more than a month. Tests show the cases are all the highly infectious Delta variant, which begins to spread in the community.

June 2021: Morrison suggests some younger Australians take the AstraZeneca vaccine after discussing it with their doctor, a move opposed by some state governments who accuse him of failing to secure sufficient supplies of the Pfizer vaccine.

June 2021: Nearly all Australians under 40 are prevented from receiving the Pfizer COVID-19 vaccine due to inadequate supplies, prompting widespread anger and frustration.

Australia is receiving about 300,000 doses of the Pfizer vaccine a week. Australia's Minister for Health Greg Hunt says supplies of the Pfizer vaccine will increase to about 1 million doses a week in August before growing to 2 million a week in October. This, he says, will mean Australia can rapidly accelerate its COVID-19 inoculation programme late in the year.