Group B Meningococcal (MenB) Vaccine


The new MenB vaccine was introduced into the routine schedule on 1st September 2015. In this short film, experts and a mother whose child was disabled by MenB infection talk about the new vaccine.

Key Facts

This new vaccine was developed to protect against disease caused by MenB (the bacterium serogroup B Neisseria meningitidis), a major cause of meningitis and blood poisoning. (See more information on meningococcal disease.)

The MenB vaccine was introduced into the routine UK schedule on 1st September 2015. It is available to all new babies born on or after 1st July 2015. The vaccine is given at 2 and 4 months, with a booster at 12 months. There is a catch-up programme for babies born between 1st May 2015 and 30th June 2015. There are no plans for a catch-up programme for older children, because the main burden of the disease is in young babies, with a peak around 5 to 6 months of age.

The MenB vaccine will also offer protection against other types of meningococcal infection, including the MenW strain which is on the increase in the UK. (See our blog post on MenW for more information.) This is because some of the antigens (proteins) in the MenB vaccine are found in other types of meningococcal bacteria as well.

There is a useful list of FAQs about the MenB vaccine on the Meningitis Research Foundation website .


The vaccine is inactivated, and cannot cause the disease itself.

It contains four proteins taken from group B Neisseria meningitidis bacteria. The combination of proteins was chosen to protect against the majority of MenB strains. They are also expected to protect against other types of meningococcal bacteria, including MenW.

It contains a small amount of aluminium which strengthens and lengthens the immune response to the vaccine. This is not a cause for concern. See more information on aluminium in vaccines.

It also contains small amounts of:

  • salt (sodium chloride)
  • sugar (sucrose) and an amino acid called histidine, both used as acidity regulators. (Amino acids are proteins made by the human body which are also found in many foods including dairy products, meat and fish.)

The vaccine may contain traces of kanamycin, an antibiotic used in the production process. See more information on antibiotics in vaccines.

Latex may be used in the packaging of the MenB vaccine.

The MenB vaccine used in the UK does not contain the preservative thiomersal (mercury).

Side Effects

Studies show that about 2 out of every 3 babies get a fever over 38º C when they are given the MenB vaccine with other routine vaccines at 2 and 4 months of age. The level of fever depends on the child, and has nothing to do with how well the vaccine has worked. The NHS has produced a leaflet for parents on using paracetamol to prevent and treat fever after MenB vaccination .

Very common side effects in babies and children up to 10 years old:

  • Fever between 38º C and 40º C (affecting about 2 out of every 3 babies)
  • Loss of appetite
  • Sleepiness
  • Unusual crying
  • Sickness and diarrhoea

Very common side effects in children, teenagers and adults:

  • Pain, tenderness, redness, swelling, rash and/or hardness of the skin at the injection site

Uncommon side effects in babies and children up to 10 years old (you should consult your doctor if these occur, mainly to check that it is the vaccine causing these symptoms, and not some unrelated disease):

  • High fever (over 40º C)
  • Seizures
  • Dry or itchy skin

Side effects in children over 11 and adults:

  • Painful muscles and joints
  • Feeling sick
  • Feeling generally unwell
  • Headache

More serious reactions to the vaccine have not been identified yet. However, there is not enough data to rule out the possibility of a rare but serious reaction.

As with any vaccine, medicine or food, there is a very small chance of a severe allergic reaction (anaphylaxis). Anaphylaxis is different from less severe allergic reactions because it causes life-threatening breathing and/or circulation problems. It is always serious but can be treated with adrenaline. In the UK between 1997 and 2003 there were a total of 130 reports of anaphylaxis following ALL immunisations, but all of these people survived. Around 117 million doses of vaccines were given in the UK during this period, making the overall rate around 1 in 900,000. Depending on the cause of the reaction, and following expert guidance, the person may be able to have vaccinations in the future.

Reactions listed under ‘possible side effects’ or ‘adverse events’ on vaccine product information sheets may not all be directly linked to the vaccine. See Vaccine side effects and adverse reactions for more information on why this is the case.

See more information on the monitoring of vaccine safety.

More information

The MenC vaccination programme was successfully introduced in the UK in 1999. In the last 10 years, about 90% of the cases of meningococcal disease in the UK have been caused by group B infections. Around 600 people a year in the UK are infected by MenB, mainly babies and children. About 10% of those who get the disease will die (50-60 people a year).

The MenB vaccine has been tested on thousands of adults and children, and from these clinical trials it is thought that the new vaccine will prevent a high proportion of cases of group B meningococcal disease. However because the disease is rare, the exact number of cases that will be prevented will not be known until the vaccine has been used routinely.

Trials have assessed the MenB vaccine when it is given alongside vaccines containing diphtheria, tetanus, polio, pertussis, Hib and Hepatitis B, and this has shown that they can be given together. Higher rates of fever and local tenderness at the injection sites were noted when the vaccines were given together, but there was no effect on the vaccines’ ability to stimulate an immune response. There are no data yet on giving the licensed MenB vaccine with the rotavirus vaccine, the MenC vaccine, the HPV vaccine, the 13-valent PCV or flu vaccines.

See also our blog posts on the MenB vaccine in the UK:

January 2013: new MenB vaccine licensed in Europe

July 2013: UK says 'no' to MenB vaccine

March 2014: MenB vaccine recommended for introduction into the UK schedule

March 2015: UK government announces introduction of MenB vaccine

Published by Sarah Loving
Medical content reviewed by Professor Andrew Pollard
Please email us if you have comments about the Vaccine Knowledge website. We can’t answer all the individual queries we get, but we will use your suggestions and questions to improve the website. You should consult your doctor or other healthcare provider if you need specific advice on vaccines for you or your child.
Last updated 14 December 2015

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Using paracetamol after MenB vaccine - NHS leaflet for parents

MenB: Charlotte's story

The MenB vaccine in the UK

MenB blog: January 2013

MenB blog: July 2013

MenB blog: March 2014

MenB blog: March 2015