Australia had an unusually early and fairly severe flu season this year. Since that may foretell a serious outbreak on its way in the United States, public health experts now are urging Americans to get their flu shots as soon as possible.

“It’s too early to tell for sure, because sometimes Australia is predictive and sometimes it’s not,” said Dr. Daniel Jernigan, director of the influenza division of the Centers for Disease Control and Prevention. “But the best move is to get the vaccine right now.”

The number of cases of flu in this country is still quite low, according to the weekly CDC FluView released Friday. But as the weather cools, it is expected to ramp up.

In 2017, Australia suffered its worst outbreak in the 20 years since modern surveillance techniques were adopted. The 2017-18 flu season in the U.S., which followed six months later as winter came to the Northern Hemisphere, was one of the worst in modern U.S. memory, with an estimated 79,000 dead.

This year’s Australian outbreak began in April, two months earlier than usual, and persisted into October.

And there were more flu-related deaths than usual, while hospitalization rates and nursing home outbreaks “were at moderate to high levels,” said Ian Barr, deputy director of the World Health Organization Collaborating Center for Reference and Research on Influenza in Melbourne.

Direct comparisons of mortality rates are difficult because Australia counts only deaths in which a hospital declares influenza the cause; there were 662 this year, and 745 in 2017.

Not only is the U.S. population 13 times bigger, but the CDC — aware that flu triggers even more deaths from pneumonia, sepsis, heart attack and other illnesses — looks at the increased death rates from many illnesses in bad flu years and calculates how many were probably due to influenza.

At the peak of the 2017-2018 season, the CDC estimated that more than 56,000 Americans would die. Officials later calculated that 79,000 had — which, the agency noted, is more people than usually fill a Super Bowl stadium.

In 2017, Australia’s deadly season set off alarm bells in Britain, where tabloids featured headlines about the “killer Aussie flu.”

But no such dire warnings were issued to Americans, in part because of turmoil at the CDC and the Department of Health and Human Services.

The Trump administration’s first HHS secretary, Dr. Tom Price, resigned in September 2017 after it was revealed that he had spent $400,000 chartering private jets at taxpayer expense. (One day earlier, Price had set an example by getting a flu shot on camera, but the room was filled with political reporters shouting questions, and he fled with his suit jacket in hand.)

Last month, Price’s successor, Alex Azar, also got a flu shot on camera at a news conference that the National Foundation for Infectious Diseases holds every year to urge Americans to get vaccinated.

Azar — who stayed through the question and answer session — made it clear that the Trump administration is firmly behind vaccination.

In his first years in office, Trump was vague about the topic; in a 2015 radio interview, he boasted that he had never had a flu shot, saying, “I don’t like the idea of injecting bad stuff into your body.” In April, however, as a measles outbreak struck New York and other states, he said American children “have to get their shots.”