Influenza (sometimes called ‘the flu’) can be much worse than a bad cold. Some babies and children who have influenza get so sick they can’t go to childcare or preschool for two weeks or more. Every year in Australia, hundreds of children get so unwell from influenza they need to be treated in hospital. Most of them are babies and children under five years.

An influenza vaccine is the best way to protect your child from serious influenza. Influenza vaccines give better protection in some years than others. This is because the types of influenza viruses making people sick from year to year can change, and the vaccines may have to be updated. 

Before the influenza season, experts gather information from around the world to work out which influenza viruses are most likely to circulate. They often get it right, but sometimes it can be hard to predict. Experts use the best information available at the time.

Influenza vaccines give your child good protection, even if they aren’t always perfect. By getting an influenza vaccine, your child will be less likely to get influenza, and less likely to get the serious conditions that influenza can cause, like severe lung infections (pneumonia) or swelling in the brain (encephalitis).

Your child can’t get influenza from an influenza vaccine. Influenza vaccines contain pieces of influenza viruses, but these can’t make your child sick like the whole virus. Some vaccines given to children in other countries have whole, weakened influenza viruses in them, but these vaccines are not used in Australia. 

It’s normal for babies and children to be a bit unsettled or even feverish for a day or two after influenza vaccination. While these side-effects can look like the flu, they are a sign that your child’s immune system is responding to the vaccine, which is exactly what’s supposed to happen. Also, the vaccine starts to protect your child after about two weeks, so if your child caught the virus before they were vaccinated (but wasn’t feeling sick yet), or in the two weeks after they were vaccinated, it might seem like the vaccine made them sick.

Serious side effects are very rare. Less than two in every 100,000 children under two years have febrile convulsions (fever fits or seizures) in the days after vaccination.¹ Febrile convulsions are caused by a sudden increase in body temperature. They can be frightening, but are usually harmless. Children are much more likely to have febrile convulsions if they get sick from influenza. In one study, about four in 100 children who were treated in hospital for influenza had a febrile convulsion.²

About one child out of every million who get an influenza vaccine has a severe allergic reaction (anaphylaxis) to one of the ingredients. Any reactions usually occur before you leave the clinic, and the medical staff are trained to help children who have this reaction recover quickly. Anaphylaxis is frightening but extremely rare.

It’s safe for children with egg allergies to get influenza vaccines.³ This is because the amount of egg in influenza vaccines is tiny (usually less than 1 microgram of egg protein per dose, which is too small to trigger an allergic reaction). Many years ago, influenza vaccines used to contain more egg protein, but the way the vaccines are manufactured is much better now. 

About one in one million (1,000,000) people who get an influenza vaccine get Guillian-Barre syndrome, which is a disorder that can cause muscle weakness, numbness and paralysis. Although it can be very serious, most people who get this disorder don’t experience any long-term effects. People infected with influenza are more likely to get Guillain–Barré syndrome than people who get the influenza vaccine.¹⁴

Children and babies six months or older need to get an influenza vaccine every year. This is because the types of influenza viruses circulating often change from year to year. Also, protection from an influenza vaccine generally lasts less than a year.

The best time to get an influenza vaccine is in April or May, before the influenza season, which is usually June to September. Your child can get an influenza vaccine at the same time as other vaccines.

Influenza vaccines must be assessed for safety by the Therapeutic Goods Administration (TGA) before they can be used in Australia. 

Once the TGA approves an influenza vaccine, it doesn’t need to be tested each year. Although the types of influenza virus particles in the vaccines may change from year to year, the way the vaccines are manufactured stays much the same. Influenza vaccines only need to be tested for safety again if the manufacturing process changes.

There are systems in place to detect any unexpected side-effects while a vaccine is being used.  For example, AusVaxSafety collects information about side-effects directly from people who have gotten the vaccine, and publishes this information every week during influenza season. The TGA, along with other health authorities and experts, investigate any potential issues detected through these monitoring systems. In very rare circumstances, they may suspend use of a vaccine. 

This is what happened in 2010, when one brand of influenza vaccine (Seqirus/ bioCSL Fluvax and Fluvax Junior) was found to have caused febrile convulsions in children under five years. We don’t give this specific vaccine to babies or children in Australia anymore.

Information about influenza (flu) disease, vaccines and recommendations for vaccination from the Australian Immunisation Handbook.

National Centre for Immunisation Research and Surveillance: Influenza vaccines for Australians - FAQs

Children get as many vaccines as possible in the first two years so they can be protected as soon as possible from diseases that can be serious.

It takes many years of research to work out the right time to give each vaccine. Independent experts gather information to help them make their recommendations. They consider which diseases Australian children are most likely to be exposed to; how serious those diseases can be for children at different ages: which vaccines are safest and which work best; how many doses are needed to provide full protection; and the age when the vaccines will give the best protection.

When vaccination is delayed or spaced out, children are left without protection from diseases for longer than they need to be. That’s why we recommend vaccinating children on time – so they can be protected as soon as possible.

Children and babies are often more likely to catch infectious diseases when they are young, and more likely to get seriously ill when they do catch them. The National Immunisation Program Schedule has been designed to protect children when they need it most.

If you choose to space out the vaccines, it means your child will need to have more vaccination appointments. Researchers have found that visiting the doctor for one needle is just as stressful for children as visiting the doctor for two needles at once.¹

Some of the diseases children are vaccinated against, like whooping cough and flu, are still common among children living in Australia. In 2017 four people caught tetanus. One was a boy under four years old and one was a girl between 5 and 9 years old (10).

Others, like measles are less common in Australia but are more common in nearby countries in the Pacific and South East Asia. Vaccinating your child will protect them from diseases which could be brought into Australia by travellers, or which they might catch if they travel overseas with you.

Some of the diseases we vaccinate children against, like polio, have become very rare in Australia because vaccination has stopped them from spreading. We still vaccinate Australian children against these diseases to stop them from coming back.

The schedule of recommended vaccinations changes from time to time for a number of reasons. For example:

• A new vaccine could be added to the schedule, protecting children from a disease it hasn’t been possible to protect them from before.

• A ‘combination vaccine’ that provides protection against multiple diseases might be released after years of research and development, reducing the number of needles children need to get overall.

• A vaccine that is better, safer, more effective or less expensive than previous versions might be introduced.

Sometimes booster doses are added to the schedule to strengthen the protective effect of a vaccine.

The schedule is different in other countries because patterns of disease, strains of viruses or bacteria, medical care, available vaccines and their costs vary from country to country.

Medical experts and health economists consider all the available information about children and diseases and decide which vaccines should be given to children in their countries at what ages. In Australia, medical experts and health economists from a variety of independent advisory groups decide which vaccines should be provided to children living in Australia.²

Adjuvants help strengthen the immune system’s response to the antigens in vaccines. In some cases this means fewer needles are needed for a child to be fully protected against a disease.

The most commonly used adjuvants are salts called aluminium hydroxide, aluminium sulphate and potassium aluminium sulphate. They are commonly referred to as ‘alum’. The amount of aluminium contained in vaccines is tiny.

Preservatives protect vaccines from becoming contaminated with harmful bacteria or fungi. The most common preservative used in vaccines is a tiny amount of alcohol.

Thiomersal, which is a salt that contains a tiny amount of mercury, is no longer used as a preservative in any vaccines routinely given to children in Australia. This is because the vaccines we use come in a single dose package and therefore do not need a preservative. Thiomersal is still used in some other parts of the world where single dose packages are too expensive or too expensive to transport. However, it is safe and effective as a preservative.

Stabilisers are usually sugars or oils that prevent vaccines from going off (spoiling) or sticking to the sides of their containers or syringes.

Residues are tiny amounts of substances that remain in the vaccine after the manufacturing process.

Most of these substances are removed from the final vaccine product, but small amounts remain. In such tiny amounts, these residues are harmless, and most are already present in our bodies. For example, tiny traces of formaldehyde can be detected in some vaccines. Formaldehyde is used to inactivate viruses, so they can be safely used as antigens in vaccines. Much larger amounts of formaldehyde are produced naturally in healthy human bodies than can be detected in vaccines.³

The diluent used in vaccines is usually sterile water or saline (salt water). Diluents have no effect on the body. They are included in vaccines to ensure that the smallest useful dose can be given to children. Vaccines are mostly made up of water or saline.

Some side effects are so rare they can’t be detected even after studying the effects of a vaccine on tens of thousands of people. For that reason, the safety of vaccines continues to be monitored even after they are in routine use. Reports of possible side effects made by parents and health professionals are carefully reviewed. These reviews can signal the need for further investigation and studies.

In addition, large populations of people who receive vaccines are often studied to identify any possible links between vaccination and rare or serious health conditions.

Any suspected problem with a vaccine is thoroughly investigated by the Therapeutic Goods Administration (TGA). These investigations involve other health authorities including state and federal governments and medical experts. Investigations usually involve more tests of vaccine quality and manufacturing processes and studies of vaccinated and unvaccinated people who have and who have not had reactions.  

If a suspected problem could be serious, authorities will consider a range of actions including suspending use of the vaccine during the investigation.

This is what happened in 2010 when doctors and parents began reporting that some children were experiencing febrile seizures (fever fits) after receiving an influenza vaccine. Febrile seizures are caused by a sudden increase in body temperature and are usually harmless.⁴ I Influenza vaccination for children was temporarily suspended until the matter could be investigated.

The investigation found that children who received one particular brand of influenza vaccine – BioCSL Fluvax^TM – experienced febrile seizures much more often than children who received other brands. That vaccine is no longer registered for use in children under five years of age but there are other seasonal influenza vaccines that children can have.

Vaccinating babies when they are older leaves them without protection against diseases that can be serious. This means they aren’t protected at an age when those diseases are most common or most serious.

Babies and young children are most vulnerable to infections when they are very young. Vaccinating them before they come into contact with serious infectious diseases gives babies the best possible protection.

Allowing children to develop immunity by catching infectious diseases is not safe. Catching a vaccine-preventable disease can protect a child from catching it again, but it can also make them seriously ill in the process. Occasionally children in Australia still die as a result of catching a vaccine-preventable disease.

Vaccination is recommended because it is the safest way to develop immunity. Vaccines are designed to stimulate immunity without causing disease. The side effects of vaccination are usually mild (like getting a sore arm) and pass quickly but the diseases they prevent can cause serious illness requiring hospital treatment.

Some of the diseases children are vaccinated against, like whooping cough and flu, are still common among children living in Australia. In 2017 four people caught tetanus. One was a boy under four years old and one was a girl between 5 and 9 years old ¹⁰.

Others, like measles are less common in Australia but are more common in nearby countries in the Pacific and South East Asia. Vaccinating your child will protect them from diseases which could be brought into Australia by travellers, or which they might catch if they travel overseas with you.

Some of the diseases we vaccinate children against, like polio, have become very rare in Australia because vaccination has stopped them from spreading. We still vaccinate Australian children against these diseases to stop them from coming back.

A number of high-quality studies have compared the health of large numbers of vaccinated and unvaccinated children over many years. The largest study included 537,303 children born in Denmark and found that unvaccinated children were just as likely to develop autism as vaccinated children.⁵ When the results of this study were combined with the results of nine other studies to include medical information from nearly 1.5 million children living all around the world, researchers were able to confirm that vaccination could not be causing autism.⁶

Some people think there is a connection because a British a research group, led by Andrew Wakefield, suggested that some children who had received the measles-mumps-rubella (MMR) vaccine went on to develop bowel disease and developmental disorders such as autism.⁷ The results of the research, which had included only twelve children, were published in a respected medical journal in 1998. However, in 2004 the authors retracted their claim that there was any association between vaccination and autism. The paper was withdrawn from the journal in 2010 after the General Medical Council found that results reported in the paper had “proven to be false”.⁸ The journal printed an apology.⁹

After it became clear that the MMR vaccine was not the problem, some people suggested a preservative sometimes used in vaccines packaged in multi-dose containers might be linked to autism. The preservative, called thiomersal, is a salt that contains a tiny amount of mercury. The mercury salt in thiomersal (ethylmercury) is not like the mercury compound (methylmercury) that accumulates in the human body.

None of the vaccines normally given to children in Australia are packaged in multi-dose containers, so none of them contain thiomersal or any other form or mercury.

You can’t get separate vaccines for measles, mumps, and rubella for your child because they are not available in Australia. Some people suggest using separate vaccines for measles, mumps, and rubella instead of the combined measles, mumps, and rubella (MMR) vaccine. Medical researchers are confident that vaccines don’t cause autism.