SYDNEY, April 11 (Reuters) - Australia has abandoned a goal to vaccinate nearly all of its 26 million people by the end of 2021 following advice that people under the age of 50 take Pfizer-BioNTech's COVID-19 vaccine rather than AstraZeneca's shot.

Australia, which had banked on the AstraZeneca vaccine for the majority of its shots, had no plans to set any new targets for completing its vaccination programme, Prime Minister Scott Morrison said in a Facebook post on Sunday afternoon (Apr 11).

"While we would like to see these doses completed before the end of the year, it is not possible to set such targets given the many uncertainties involved," Morrison said.

Authorities in Canberra changed their recommendation on Pfizer-BioNTech shots for under-50s on Thursday, after European regulators reiterated the possibility of links between the AstraZeneca shot and reports of rare cases of blood clots.

Australia, which raced to double its order of the Pfizer-BioNTech vaccine last week, had originally planned to have its entire population vaccinated by the end of October.

Australia's hardline response to the virus largely stopped community transmissions but the vaccination rollout has become a hot political topic - and a source of friction between Morrison and state and territory leaders - after the country vaccinated only a fraction of its 4 million target by the end of March.

About 1.16 million COVID-19 doses have now been administered, Morrison added, noting the speed of Australia's vaccination programme was in line with other peer nations, including Germany and France, and ahead of Canada and Japan.

Australia began vaccinations much later than some other nations, partly because of its low number of infections, which stand at just under 29,400, with 909 deaths, since the pandemic began.