Usual symptoms

• Hib can cause a few different kinds of infection. These include septicaemia (blood poisoning), pneumonia (infected lungs), arthritis (infected joints), cellulitis (skin infection), meningitis (brain infection) and epiglottitis (throat infection that causes swelling and can stop a child from breathing).
• Babies who get Hib infections usually have a fever, are unusually sleepy, and don’t feed well.
• Children who get Hib infections before they are two years old do not usually develop natural immunity.

Less common symptoms

• About 5 per cent of people with Hib-meningitis die. 
• About 25 per cent of people who survive Hib-meningitis have permanent brain or nerve damage. 

In Australia, children receive a ‘combined’ vaccine (also called ‘hexavalent’), which strengthens immunity to Hib, as well as diphtheria, tetanus, pertussis, polio and hepatitis B.

It is recommended that children get a vaccine that protects against Hib at two months, four months, six months and 18 months.

It is important that children get all their vaccinations on time to ensure they have the best possible protection against infectious diseases.

The vaccine works by training your child’s immune system to recognise and get rid of the Hib bacteria and their toxins. The vaccine contains antigens, which are tiny, harmless fragments of the outer layer of the Hib bacteria (the ‘bacteria capsule’). 

When your immune system detects the antigens in the vaccine, it produces proteins called antibodies. These antibodies are like soldiers that recognise and remember the Hib outer layer. If your child is ever exposed to the real Hib bacteria, their immune system will recognise them quickly and fight them off using the antibodies it created after vaccination.²

The Hib vaccine does not contain any blood products and is not a ‘live’ vaccine. The antigens are made synthetically and are not the real bacteria. They cannot replicate themselves or cause disease. 

Children who have their first three doses of the Hib vaccine have an approximately 94 per cent lower risk of becoming ill from Hib disease.³ 

In Australia, research shows that children who have received at least one dose of a Hib vaccine are at an approximately 90 per cent lower risk of becoming ill from Hib disease.⁴ 

No, there is no risk that your child will catch Hib because the vaccine does not contain the live bacteria that causes the disease.

• Up to 33 per cent of children who have vaccines that protect against diphtheria, tetanus, pertussis (whooping cough), Hib, or polio experience redness at the injection site that lasts up to a few days.
• Up to 20 per cent of children who have vaccines that protect against diphtheria, tetanus, pertussis (whooping cough), Hib, or polio develop a mild fever that lasts one or two days.  
• About 10 to 13 per cent of people who have vaccines that protect against diphtheria, tetanus, pertussis (whooping cough), Hib, polio, or hepatitis B experience mild swelling or pain at the injection site that lasts one or two days. 
• About 5 to 10 per cent of babies who have vaccines that protect against polio experience decreased appetite.
• About 2 per cent of people who get booster doses of a vaccine that protects against diphtheria, tetanus and pertussis (whooping cough) get a sore red, swollen arm. The swelling starts in the first two days after vaccination. It lasts for one to seven days and then gets better. 
• About 1 per cent of children who have a vaccine that protects against polio get a hard lump at the injection site that lasts a few days or weeks. 

• Babies who get a fever (for any reason) occasionally experience a fit (febrile convulsion) that lasts from a few seconds to a few minutes. Febrile convulsions don’t have long-term effects on a child’s health and development.
• Some people who get vaccines that protect against hepatitis B experience nausea or aches in their muscles or joints in the days afterwards.
• About 0.0032 per cent of children aged 12 months or under who get a vaccine that protects against pertussis (whooping cough) experience hypotonic-hyporesponsive episodes (HHE). These children get very pale, go limp, and don’t respond to their surroundings. Their lips and fingernails can also turn blue. Most reactions last less than 30 minutes and can occur anytime from vaccination up to about 48 hours after vaccination.⁵ HHEs don’t usually have any long-term effects on children’s health.
• About 0.0001 per cent of people have an allergic reaction following vaccination that affects their whole body, called anaphylaxis. This reaction usually happens within 15 minutes of getting the vaccination and can be treated with an injection of adrenaline. People who have this reaction usually recover quickly and don’t experience any long-term effects.

Prior to the introduction of immunisation, Hib was the most common cause of bacterial meningitis in Australian children. Vaccination has had a significant impact on the incidence of the disease among Australian infants. In the seven-year period between 1993 (when the vaccination was introduced) to 2000, Hib notifications declined by 87 per cent among children under 4 years of age. It is now a very rare disease in Australia.^6,7