Australia's deputy prime minister has condemned the "disgusting" behaviour of some Australian Open tennis final fans who loudly booed mention of the country's Covid-19 vaccine rollout.
The booing happened during an awards ceremony after the men's final, when a tennis official referred to global vaccine efforts as a sign of optimism.
Australia started its national inoculation programme on Monday.
Some cities saw anti-vaccination protests held at the weekend.
The men's number one player Novak Djokovic won the final against Russian Daniil Medvedev on Sunday.
Djokovic has been criticised in the past for appearing to have a casual attitude towards virus-related restrictions and faced scrutiny last year over comments he made about vaccinations.
The demonstration was criticised by Deputy Prime Minister Michael McCormack on Monday.
"I don't like booing at any event, and certainly any sporting event," he told reporters in Canberra.
"This vaccine is going to get our country back to some sort of pre-Covid normality."
Australia kicked off the first stage of its vaccine programme on Monday. Frontline, health and quarantine workers are in line to get the first of 60,000 Pfizer vaccine doses this week.
While the vaccine has broad support locally, it has also sparked protests. On Saturday, small crowds of anti-vaccination demonstrators marched in cities, including Melbourne and Sydney, to protest against its rollout.
In Melbourne, where the Australian Open was held, the crowd also booed mention of the Victorian state government when Tennis Australia chief Jayne Hrdlicka thanked authorities.
Last week, the government ordered Victoria residents into a snap five-day lockdown amid fears of an outbreak. The tennis event was allowed to proceed and the virus did not spread.
Australia's low case numbers
The vaccine is not mandatory in Australia but is highly encouraged by health authorities. Australia aims to inoculate four million people - about a sixth of the population - by early March.
Prime Minister Scott Morrison was among the first to get his jab on Sunday, broadcasting the event in an effort to boost national confidence.
Government polling has shown that close to two-thirds of Australians say they will "definitely" get vaccinated, while just over one quarter are "unsure".
Australia has received doses of the Pfizer vaccine and last week approved the AstraZeneca jab.
Both have undergone extensive safety checks and are already being used in several countries.
Critics have suggested the relative delay of the vaccine's roll-out in Australia - compared to other Western nations - could explain a recent small uptick in people "unsure" about receiving it.
The government has defended the slow roll-out, saying it wanted all elements fully approved by regulators, and that the low infection rate meant it didn't warrant urgent distribution.
As of Monday, Australia had under 40 active cases, with most in its hotel quarantine programme. The nation has recorded about 29,000 cases and 909 deaths in the pandemic - far fewer than many nations.