{"id":592921,"date":"2026-04-08T07:15:09","date_gmt":"2026-04-08T07:15:09","guid":{"rendered":"https:\/\/www.newsbeep.com\/au\/592921\/"},"modified":"2026-04-08T07:15:09","modified_gmt":"2026-04-08T07:15:09","slug":"when-is-the-best-time-to-get-your-flu-shot-two-infectious-diseases-experts-explain","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/au\/592921\/","title":{"rendered":"When is the best time to get your flu shot? Two infectious diseases experts explain"},"content":{"rendered":"

We usually have to wait until winter approaches before we see an increase in cases of influenza, or the flu. But we have already seen a lot of flu this year, with 25,000 cases reported<\/a> from January to March \u2014 and that’s only a fraction of actual case numbers.<\/p>\n

Most people with the flu recover without treatment. But it can cause serious complications<\/a> in older people, young children, pregnant women and those with underlying chronic diseases such as asthma or heart disease. Influenza kills around 3,500 Australians<\/a> a year and lands 18,000 in hospital.<\/p>\n

Most flu deaths this century were recorded in 2025<\/a><\/p>\n

There were more deaths associated with influenza last year than any other year this century, according to the Australia Bureau of Statistics.<\/p>\n

Vaccination is the best way to protect against flu and is recommended<\/a> for everyone over the age of six months.<\/p>\n

Flu vaccines are free for certain risk groups<\/a>. Others can access them (usually for a fee) at pharmacies, GP clinics and local council clinics in some states and territories. Some employers also offer vaccinations for staff.<\/p>\n

Influenza has been unpredictable since the COVID pandemic, with off-season circulation. There are also concerns<\/a> that protection may lag at the end of winter. So when is the best time to get vaccinated?<\/p>\n

What are the symptoms and how does it spread?<\/p>\n

Flu symptoms<\/a> include a cough, sore throat, fever, body aches and fatigue.<\/p>\n

Flu spreads from person to person via small respiratory droplets when you talk, cough and sneeze. It may also spread by touching a surface or object where infected droplets have landed, but this is less common.<\/p>\n

So if you have flu-like symptoms<\/a>, it’s important to stay at home.<\/p>\n

Flu spreads more in the winter months due to increased contact between people and time spent indoors. Some studies also suggest influenza viruses transmit better in the cold<\/a>.<\/p>\n

What strains are around this year? And what is super-K?<\/p>\n

Typically, human flu cases<\/a> are caused by four virus strains, A(H3N2), A(H1N1), B\/Victoria, and B\/Yamagata.<\/p>\n

So far this year in Australia<\/a>, almost 98 per cent of cases have been influenza A(H3N2), and the remaining have been influenza B\/Victoria.<\/p>\n

\"A<\/p>\n

Theoretically, the best time to get the flu vaccine is about two weeks before flu cases start to rise. (ABC News: Kym Agius)<\/p>\n

In late 2025<\/a>, a new variant of the H3N2 strain known as subclade K<\/a> or “super-K” emerged in the Northern Hemisphere winter.<\/p>\n

Super-K contributed to the unusual increase<\/a> in flu numbers over summer in Australia. But there is no evidence to suggest it’s more severe than other H3N2 strains.<\/p>\n

What does this year’s vaccine protect against?<\/p>\n

Each year<\/a>, the flu vaccine is designed to protect against a mix of different virus strains, depending on what strains are currently circulating.<\/p>\n

This year’s flu vaccine contains two new strains<\/a> for the influenza A(H1N1)pdm09 and A(H3N2) subtype virus components and an existing B strain:<\/p>\n

an A\/Missouri\/11\/2025 (H1N1)pdm09-like virusan A\/Singapore\/GP20238\/2024 (H3N2)-like virusa B\/Austria\/1359417\/2021 (B\/Victoria lineage)-like virus.<\/p>\n

The Singapore strain in the vaccine is closely related to the super-K strains that have been circulating, so it should provide better protection than the vaccine used last year in the northern and southern hemispheres.<\/p>\n

The composition of the Southern Hemisphere vaccine for use in Australia is different from the Northern Hemisphere composition for the 2025\u201326 winter.<\/p>\n

How effective will this year’s vaccine be?<\/p>\n

It’s too early to know how well the vaccine will work against preventing infection and severe disease.<\/p>\n

Preliminary Australian data<\/a> suggests people who received the flu vaccine in 2025 were 53 per cent less likely<\/a> to be hospitalised with influenza or visit a GP for flu symptoms compared with unvaccinated people.<\/p>\n

The dark side of addressing vaccine hesitancy in Australia<\/a><\/p>\n

Addressing vaccine hesitancy requires skill and patience \u2013 some days, the people who do it feel like they\u2019re drowning in a sea of lies.<\/p>\n

In the UK, during the 2025\u201326 winter, influenza vaccines were 72\u201375 per cent effective<\/a> at protecting against flu cases needing medical attention in children and adolescents, including infections caused by super-K.<\/p>\n

Herd immunity<\/a> from influenza vaccines can also help prevent transmission to others who are unable to get vaccinated.<\/p>\n

A three-year study<\/a> in the United States, which ended in 2020, found influenza vaccines were 21 per cent effective at preventing infection among other household members.<\/p>\n

Another study<\/a> in the UK and Ireland from 2010 to 2017 found that vaccinating school-aged children reduced the amount of respiratory illnesses GPs saw across all age groups.<\/p>\n

When does the flu season peak?<\/p>\n

While we see flu cases throughout the year, the “flu season” in temperate Australia typically lasts from May to October, peaking in June and July.<\/p>\n

Theoretically, the best time to get the flu vaccine is about two weeks before flu cases start to rise.<\/p>\n

However, this is difficult to predict and the rise can start anywhere between April and July in temperate Australia, and even earlier in tropical northern Australia.<\/p>\n

How long does the flu vaccine last?<\/p>\n

There is some evidence<\/a> that the protection provided by influenza vaccines falls over six months. Immunity to flu is optimal for three to four months<\/a> after you are vaccinated.<\/p>\n

However, some studies suggest this may be an artefact<\/a> of the methods by which vaccine effectiveness is measured.<\/p>\n

Other factors may also be important. Waning protection may be more prominent in older people<\/a> and may also depend on the degree to which mutations in circulating influenza strains accumulate during the season.<\/p>\n

So when is the best time to get vaccinated?<\/p>\n

When working out the best time to get your flu vaccine, you might be balancing a theoretical benefit by waiting against the chance of actually getting the flu before you get vaccinated.<\/p>\n

Our advice is to get the vaccine when it’s available and convenient, sometime around April or May<\/a>.<\/p>\n

But if you’re travelling overseas, particularly for those travelling to the Northern Hemisphere in winter, aim to get your flu vaccine around two to four weeks before you leave.<\/p>\n

If you’re pregnant<\/a>, an ideal time to get the influenza vaccine is with RSV (respiratory syncytial virus) and pertussis vaccines from 28 weeks of pregnancy. This protects both mother and baby.<\/p>\n

Finally, young children getting their first flu vaccines<\/a> should have two doses four weeks apart. Getting their first dose earlier in the season will leave plenty of time for the second dose before the influenza season starts.<\/p>\n

Meru Sheel is professor of infectious diseases and global health at the University of Sydney. Allen Cheng is professor of infectious diseases at Monash University. This piece first appeared on The Conversation<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"We usually have to wait until winter approaches before we see an increase in cases of influenza, or…\n","protected":false},"author":2,"featured_media":592922,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[64,63,289486,22659,173674,154,289487,137,17974,173673,289489,7277,289488],"class_list":{"0":"post-592921","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-health","8":"tag-au","9":"tag-australia","10":"tag-best-time-to-get-a-flu-vaccine","11":"tag-covid-vaccine","12":"tag-flu-shot","13":"tag-flu-vaccine","14":"tag-flu-vaccine-australia","15":"tag-health","16":"tag-infectious-disease","17":"tag-influenza-vaccine","18":"tag-should-i-get-a-flu-shot","19":"tag-virus","20":"tag-when-is-flu-season"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/592921","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=592921"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/592921\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/592922"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=592921"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=592921"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=592921"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}