“I would expect it to be as mandatory as you could possibly make it,” Morrison told Australian radio station 3AW. “There are always exemptions for any vaccine on medical grounds, but that should be the only basis.”

Australia signed an agreement with pharmaceutical giant AstraZeneca to produce and distribute AZD1222, the coronavirus vaccine candidate licensed to AstraZeneca and developed by researchers at Oxford University, Morrison announced late Tuesday.

AZD1222 is widely considered the global front-runner in coronavirus vaccine candidates. It is currently in Phase III clinical trials, which will test the efficacy and safety of the vaccine in thousands of human volunteers. Australia’s government is also supporting vaccine development efforts by researchers at the University of Queensland and Australian biotech firm CSL Ltd., but the Oxford vaccine is “more advanced,” Morrison said.

If clinical trials for the vaccine are successful, Morrison said on Wednesday, doses will be made available to Australians “hopefully early next year. If it can be done sooner than that, great.”

Vaccine doses will be free and available to the whole population, but health care workers and more vulnerable groups like elderly people and people with disabilities may get priority access. For a vaccine to work, at least 90% of the population needs to be inoculated.

Morrison told 3AW that Australia needs “about 95%” of the population to be vaccinated, and he said he is prepared for possible backlash at the prospect of a mandatory vaccine.

“I was the minister that established ‘No jab, no play,’ so my view on this is pretty clear,” Morrison said.

“No jab, no play” refers to national and state legislation that requires children to meet certain vaccination requirements for families to receive childcare services and other subsidies. The government introduced the program when Morrison was Australia’s minister for social services, and in 2015, Morrison announced that “conscientious objector” exclusions from the immunization requirements would no longer be given out.

“We need the most extensive and comprehensive response to this to get Australia back to normal,” Morrison said, adding that the government has not yet made an official decision on making vaccines mandatory and will do so when trials are finished and more medical information is available.

By comparison, Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, told Healthline on Tuesday that he does not think the U.S. government will make a coronavirus vaccination mandatory.

According to data from the Organization for Economic Co-operation and Development (OECD), 95% of children in Australia are vaccinated against measles, higher than the 92% figure for the U.S. and 90% in Canada, and lower than other countries including Portugal, Japan, and Greece at 99%.

Australia had one of the world’s most successful coronavirus responses earlier this year, logging no more than 50 daily cases between late April and late June, but an outbreak at a hotel for quarantining return travelers sparked a second wave. A total of 438 people have died of COVID-19 in Australia, almost 24,000 have been infected, and 15,000 have recovered.