Australia was virtually flu-free for a couple of years, but the disease has recovered, and then for about the last month or so.
All 10,600 cases of influenza were reported to the National Notification Disease Surveillance System during the first third of this year, with more than 7,000 diagnosed in the fortnight between April 25 and May 8.
This compares to only 598 reported cases of flu throughout 2021, thanks in large part to the closure of borders and restrictions on COVID.
Now, as Australians go into winter with little natural immunity and face the potential risk of co-infection with COVID-19, experts say getting vaccinated against the flu is more important than ever.
“We have about 600,000 children under the age of two who have never seen the flu, so it’s a pretty sizeable population of young children who are totally susceptible,” Sheena Sullivan, an infectious disease epidemiologist at the Doherty Institute, told ABC News. .
“And then for our larger populations … we don’t know exactly how often people get infected, but there would normally be a higher level of protection in the community than there is now.”
Sydney pediatrician Nick Wood said hospitals were already seeing more flu cases in young children, who, along with older adults, pregnant women and adults with chronic illnesses, face a higher risk of complications if they infect.
“In the pediatric space, there are definitely more hospitalizations in children under 5 than we saw with COVID-19,” said Dr. Wood, who is also associate director of the National Center for Immunization Research and Surveillance. (NCIRS).
“Because [the flu] it has not circulated, there is not much prior natural exposure, so they are effectively naive immunologists. “
Capture of the slow flu vaccine
Some 6 million Australians have already been vaccinated against the flu this year, but that’s less than a quarter of the eligible population, said Ian Barr, deputy director of the Collaborating Center for Influenza Reference and Research of the World Health Organization at the Doherty Institute.
“It’s low. Last year, we vaccinated around 35% of eligible Australians. So right now we’re even below that.”
That said, older Australians tend to have much higher seasonal flu vaccination rates than their younger counterparts. (In 2019, only 15% of people between the ages of 20 and 50 were vaccinated against the flu).
This year’s flu vaccine helps protect against four different flu viruses. (ABC Central West: Donal Sheil)
In Australia, all people over the age of 6 months are recommended to get vaccinated against seasonal flu. Vaccination protects you from serious illnesses and also helps to protect those around you by reducing the risk of transmitting them.
Dr. Wood suspected that “vaccine fatigue” may be helping to slow absorption rates in some age groups.
“I also think the healthcare workforce is suddenly changing from‘ going to go ’with COVID-19 to‘ going to go with the flu, ’” he said.
The launch of COVID-19 vaccines, especially reinforcements over the past six months, may also have led some people to postpone their flu vaccine, Dr. Sullivan said.
“There was a bit of confusion about whether the flu vaccine could be obtained at the same time, and that meant that the absorption of the vaccine was a little lower.”
(You can now get your COVID-19 booster and flu shot at the same time).
The flu vaccine is an “excellent combination” so far
While vaccination is the best way to protect yourself from the flu, flu vaccines offer better protection in some years than in others.
This is because the flu-causing viruses can mutate quickly and escape our immune defenses, as well as any protection afforded by vaccines.
To stay one step ahead, the World Health Organization (WHO) keeps track of which viruses are circulating and where, and uses it to predict, in September of each year, what will be in our next seasonal flu vaccine.
Vax flu protects against four viruses
- Two flu A:
- Two B flu:
- B / Victoria tends to infect younger people
- B / Yamagata can now be eradicated
So how have you been this year?
According to Professor Barr, things are looking pretty good right now.
“Now things may change over the course of the season, but we have a game as good as we could expect.
“Actually, it’s too early to tell how it works in terms of vaccine effectiveness, but in terms of circulating viruses and the coincidence of the vaccine, they’re a great combination at this stage.”
Of the four flu viruses covered by the vaccine, two are influenza A and two are influenza B.
In general, influenza B viruses only infect people, while influenza A viruses, such as H1N1 or swine flu, can bounce between us and other animals.
This year, influenza A viruses have been behind the lion’s share of laboratory-confirmed cases, Professor Barr said: “It’s about 75% H3N2 and 25% H1N1.”
The highest level of protection against a flu vaccine occurs during the three to four months after vaccination. (ABC: Emma Wynne)
Although there is very little circulating B virus, which only includes 0.2% of laboratory-confirmed cases, the vaccine appears to be less effective against it, said University of Queensland virologist Ian Mackay.
“This is something that needs to be monitored, because if we were to expand it or we should have more cases [travellers] introducing it to Australia … could cause more disease. “
Most powerful vaccines for older Australians
The proper functioning of the flu vaccine also depends on your age and general health.
The INCIRS estimates that about 50-60% of young children and healthy adults under the age of 65 can prevent the flu vaccine, although this figure varies from year to year.
But older people and those with compromised immune systems may not respond as well to vaccination, which means they may be less protected.
That’s why Australians over the age of 65 are recommended to take one of the two improved flu shots, specifically designed to boost their immune system’s response to the vaccine.
“They have an adjuvant [in the vaccine] or higher dose vaccine, basically because the immune system only needs more immune stimulant, “Dr. Wood said.
“For younger children, their immune system is a little more robust … it’s the same thing we were seeing with COVID vaccines.”
How serious is this year’s flu?
While the flu can be a mild illness, which causes a few days off work with fever, aches and sore throats, it can also cause very serious illnesses and should not be confused with the common cold.
“I think people get a little complacent about the flu,” Dr. Mackay said.
“But we saw in 2017 and 2019 very big flu years that had a lot of people in the hospital. We saw deaths, visits to the ICU and a lot of free time.”
The flu is easily transmitted, mainly through large drops of particles produced by sneezing and coughing. (ABC News: Cason Ho)
According to this year’s annual FluTracking data, respiratory disease levels are “moderate and rising sharply, especially in children 17 and under.”
Officially reported figures suggest that the flu hospitalizes about 5,100 people and kills 100 each year in Australia, but it is believed that these figures do not represent the true burden of the disease.
A mathematical modeling study in 2008 suggests that the flu is likely to be responsible for more than 3,000 deaths and 13,500 hospitalizations each year, and only in people over the age of 50.
It is never too late to get vaccinated
The INCIRS recommends that eligible Australians go out for the flu around April or May, when the flu season begins to rise.
Like other vaccines, the effectiveness of an influenza vaccine decreases over time, but an April / May vaccine should still provide good protection when the flu season peaks in August or September. .
If you haven’t been vaccinated against the flu this year, it’s not too late, but try to get it as soon as you can to get some protection, according to the INCIRS.
Whenever available, flu vaccines will be offered throughout the flu season.
What if you already had the flu? You should still get your chance.
It will help reduce the risk of getting sick from other strains of the flu virus that make the rounds.
Other ways to reduce the risk of getting the flu (and other illnesses) should be fairly familiar by now: social distancing, wearing a mask when you’re around other people, washing your hands. hands and stay home.
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