SYDNEY - The Australian government has agreed to purchase 2 more COVID-19 vaccines in development, beefing up the country's prospective arsenal against the pandemic to 135 million doses as it aims to complete a mass inoculation program within months.

Prime Minister Scott Morrison said on Thursday the government will buy 40 million vaccine doses from Novavax, and 10 million from Pfizer and BioNTech.

That adds to the 85 million doses Australia has already committed to buy from AstraZeneca and CSL Ltd should trials prove successful, taking the country's total anticipated outlay to A$3.2 billion ($2.3 billion).

"We aren't putting all our eggs in one basket," Morrison told reporters in Sydney.

Health Minister Greg Hunt said the Novavax and Pfizer-BioNTech vaccines, which would be manufactured in the United States and Europe, would complement the AstraZeneca and CSL products, which would be manufactured in Australia.

"That means we are now in a very strong position with the portfolio of 4 different vaccines, 2 protein, 1 viral vector and 1 MRMA, which is the Pfizer vaccine, and that's innovative - the world hasn't had an MRMA vaccine before," Hunt told TV broadcaster Nine Network.

The Pfizer-BioNTech, AstraZeneca and Novavax vaccines are considered to be among the leading candidates in the global race to receive regulatory approval.

Should trials prove successful, Australia expects to receive the first batches of the AstraZeneca vaccine in early 2021 and begin a mass rollout in March to be completed by the end of the year.

If all 4 vaccines come to market, Australia and its population of 26 million people will find itself with excess doses, even allowing for the fact that many of the candidates in development require 2 doses to be effective.

Australia has said it plans to donate any excess doses to Pacific Island countries and has committed to spending around A$525 million to ensure Pacific nations and East Timor achieve full immunization coverage.

Australia is the largest aid donor to the Pacific islands and has sought in recent months to step up its engagement out of concern it risks being overshadowed by Chinese aid and financial support.

ZERO LOCAL TRANSMISSION

The announcement of the new planned vaccine purchases came as Australia recorded no cases of locally transmitted COVID-19 over the past 24 hours for the second time in a week. The country on Sunday recorded the first day without any local cases since early June.

Australia has reported just over 27,600 coronavirus cases and 907 deaths, far fewer than most other developed countries thanks to extensive testing, contact tracing and lockdowns.

As national case numbers have slowed to fewer than 10 each day, states and territories have been reopening borders and relaxing differing levels of social distancing restrictions.

Qantas Airways on Thursday said it would boost the number of flights between New South Wales and Victoria states after officials announced on Wednesday that border restrictions would be lifted later this month.

The national carrier will go from the 10 return flights it is currently operating each week between Sydney and Melbourne to more than 250 flights between the 2 states weekly. The Sydney-Melbourne route was one of the busiest in the world before the pandemic.

($1 = 1.3916 Australian dollars)