What you need to know

  • Australia experienced a big increase in rates of influenza during its most recent flu season.
  • Flu activity in the southern hemisphere can sometimes indicate similar patterns in the northern hemisphere.
  • The influenza A (H3N2) strain of the virus was the main culprit behind most of the reported cases in Australia.
  • It’s important to receive your flu shot before flu season starts in October.

What happened in Australia?

It’s always a good idea to get vaccinated as flu season approaches. But this year, it’s even more so, as chances of catching the virus could be higher than usual. Australia’s Department of Health reported a significant uptick in the prevalence of the influenza virus during its current flu season, which lasts from May to October. Flu activity in the southern hemisphere can sometimes indicate similar patterns in the northern hemisphere, which begins flu season in October.

“It is important to note that influenza is always unpredictable,” said Litjen Tan, MS, Ph.D., and Chief Strategy Officer of the Minnesota-based Immunization Action Coalition in an email. “However, the southern hemisphere has certainly been severely hit during their current flu season, and often that does suggest a more severe flu season for us as well.”

Australia’s National Notifiable Diseases Surveillance System confirmed that there were 93,711 cases of influenza by mid-August — more than twice the number of infections reported within the same period last year. There were also twice as many influenza-related hospitalizations in the country, with 1,429 occurring this year and 719 last year. More people also died as a result of contracting the illness, with 52 deaths, compared to 27 last year.

What can we expect in the United States?

The government report named the influenza A (H3N2) strain as the main culprit behind most of the reported cases of influenza in Australia. It was also responsible for 81% of deaths related to catching the flu. Arnold Monto, a professor at the University of Michigan School of Public Health, said that this type of virus is known to cause a high rate of severe flu symptoms. But without more information about Australia’s vaccines and other variables, he finds it difficult to predict the outcome in the U.S.

"At this point, it is hard to draw conclusions about what the Australian situation means to the U.S.,”  Monto said in an email. “We need to learn more about the exact nature of the outbreak, and we will probably have more news soon. Questions to be answered are how well the vaccine is working and whether antivirals were appropriately used in the reported nursing home outbreaks.”

Monto thinks Australia’s flu season might mean that the U.S. experiences an earlier seasonal onset. Viral activity could peak toward the end of November instead of mid-January. However, he noted that it is often difficult to make conclusions based on what occurs in other parts of the world.

How can you protect yourself?

According to the Centers for Disease Control and Prevention (CDC), each flu season can bring a new strain of the virus and vaccine effectiveness can vary. For the upcoming 2017-18 season, which begins in October and ends in May, vaccine strains are selected based on global surveillance data, the genetic makeup of viruses, immune responses to influenza strains, antiviral resistance, and vaccine effectiveness. Trivalent vaccines will protect against influenza A (H1N1), influenza A (H3N2), and influenza B (Victoria lineage). Quadrivalent vaccines will protect against the three strains in addition to influenza B (Yamagata lineage).

The CDC recommends a yearly flu shot for everyone 6 months and older before flu season begins, which can be done by visiting your general practitioner or local pharmacy. Taking preventative measures can reduce the chances of falling ill, doctor visits, taking sick days, and flu-related hospitalizations. Pregnant women, the elderly, very young children, and those with certain health conditions and compromised immune systems can be more susceptible to serious flu complications. Getting a flu shot can also help ensure that you don't pass the illness to one of these more vulnerable people. Those who are very sick or are at risk for more severe symptoms should seek immediate treatment from their doctors with influenza antiviral medication.

The University of Michigan School of Public Health also suggests some common sense practices that can help prevent spreading the flu. These practices include washing your hands often; keeping hands away from your eyes, nose or mouth; leading a healthy lifestyle, avoiding contact with sick people and shielding others from coughs and sneezes with a tissue.

“The most important thing for all of us is to not gamble with whether the upcoming season will be more or less severe,” Tan said. “Why take a chance? We have safe and effective influenza vaccines that are already beginning to become available. It's a no-brainer — vaccine in the arm can protect you against flu; vaccine sitting on a shelf protects nothing.”