The Hib vaccine

The Hiberix vaccine (produced by GlaxoSmithKline) provides protection against the very contagious Haemophilus influenza type B (Hib) bacterium. Hib can cause very serious illness, including meningitis and blood poisoning (septicaemia), especially in children and young babies. Children in Ireland are given three vaccinations against Hib at 2 months, 4 months and 6 months old, as part of the 6-in-1 vaccine, and are given a booster vaccine at 13 months (Hiberix). Hiberix is a conjugate vaccine.

Hib infections have reduced in Ireland since the introduction of a vaccine in 1992 (from about 100 per year in the 1980s to 10 in 2002), though a few cases continue to be reported. The Hib vaccine has been given to over 20 million people worldwide, with no serious adverse reactions (medical conditions that may or may not be caused by the vaccine) and is considered to be extremely safe.

Most common side effects are mild and temporary. They are a result of the child's immune system responding to the vaccination, and making antibodies that will protect the child in the future. Most side effects will ease after a day or two and any discomfort can be treated with over-the-counter medicines such as paracetamol or ibuprofen (ask your pharmacist for medicine appropriate for your child's age).

Before getting the vaccination, speak to your doctor if your child has been sick or 'off form' over the past few days. Illness can reduce the effectiveness of a vaccine. The nurse or doctor administering the vaccine will check your child's temperature first, to see if they may have any other infections or illnesses.

Common side effects of Hiberix that are usually no cause for concern: soreness, redness or swelling at the injection site, high temperature, loss of appetite, vomiting, diarrhoea, irritability and unusual crying.

Other rarer side effects of Hiberix include sleepiness, fainting, rash, swelling of the injected limb, and a hard lump at the injection site. These side effects are rare and have been reported in very few children.

Remember that the benefits of receiving vaccines that protect your child from serious diseases hugely outweigh any mild side effects from vaccination.

If you are concerned about your child, contact your doctor or local hospital for advice.

Allergies to substances within vaccines can occur, though they are very rare (they happen in fewer than 1 in 10,000 people receiving the vaccine). An allergic reaction to a vaccine would happen quickly - probably before you left the GP's surgery. Signs of an allergic reaction may include itchy skin, rash, shortness of breath and swelling of the face or tongue.

Before getting the vaccination, speak to your doctor if your child has experienced any allergic reactions previously.

If you are concerned about your child, contact your doctor or local hospital for advice.

Vaccines are tested exhaustively before they are provided to the public (it normally takes 10-15 years to develop a new vaccine). Hib vaccines have been given to millions of people around the world, reducing rates of Hib (a leading cause of bacterial meningitis). The Hiberix vaccine (produced by GlaxoSmithKline) was licenced for use in Ireland in 1999, and was approved for use in the USA in 2009 following 7 clinical trials in Europe that studied the safety and effectiveness of the vaccine in more than 1,000 children.