MenB Vaccine (Meningococcal B Vaccine)

Key vaccine 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. A total of around 750 people in the UK (mostly babies and children) were infected by MenB in 2011, and around 50 of these died. (See more information on meningococcal disease.)

The MenB vaccine was introduced into the routine UK schedule on 1st September 2015. The vaccine is given at 2 and 4 months, with a booster at 12 months. 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 is also recommended for people with some long-term health conditions who are at greater risk of complications from meningococcal disease. This includes people with:

  • asplenia or splenic dysfunction (a spleen that is missing or does not work properly)
  • sickle cell anaemia
  • coeliac disease
  • complement disorders (the complement system is an important part of the immune system)

The brand name of the MenB vaccine used in the UK is Bexsero (see the Patient Information Leaflet ). It will 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.

The vaccine does not contain any live bacteria and cannot cause meningococcal disease.

The UK is the first country in the world to introduce a MenB vaccine into its routine vaccination schedule. Results from the UK programme will influence other countries' decisions about including the MenB vaccine as part of routine vaccination.

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

In this short film, experts and a mother whose child was disabled by MenB infection talk about the new vaccine.


Bexsero, the MenB vaccine used in the UK, 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.

Apart from these active ingredients (the antigens), the vaccine contains very small amounts of these ingredients:

  • Aluminium, which strengthens and lengthens the immune response to the vaccine
  • salt (sodium chloride)
  • sugar (sucrose) and an amino acid called histidine, both used as acidity regulators. (Amino acids join together to make proteins. They are made by the human body and are also found in many foods including dairy products, meat and fish.)

The vaccine may also contain traces of these products used during the manufacturing process:

Latex may be used in the packaging of Bexsero.

Other brands of MenB vaccine used in other countries may contain different ingredients. If you are not in the UK, ask for the Patient Information leaflet for the vaccine you are offered.

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 (affecting more than 1 in 10 people at each dose):

  • 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 (affecting more than 1 in 10 people at each dose):

  • 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 (affecting up to 1 in 100 people at each dose). 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

Other possible 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.

If you are concerned about any reactions that occur after vaccination, consult your doctor. In the UK you can report suspected vaccine side effects to the Medicines and Healthcare products Regulatory Agency (MHRA) through the Yellow Card Scheme . You can also contact the MHRA to ask for data on Yellow Card reports for individual vaccines . See more information on the Yellow Card scheme and monitoring of vaccine safety.

More information about the vaccine

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

Charlotte Nott developed septicaemia through type B meningococcal disease infection. In the short film below, her mother, Jenny Daniels, talks about the impact on Charlotte and the rest of her family.

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

Does the vaccine work?

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.

In February 2016 Public Health England published research which showed that the MenB vaccine should help to provide protection against the aggressive strain of MenW disease circulating in the UK , as well as protecting against MenB disease.

In September 2016 Public Health England reported on research carried out on babies in the UK who were eligible to receive the new MenB vaccine. The research showed that the number of cases of meningitis and septicaemia caused by MenB infection in these babies had nearly halved over the previous year (since the MenB vaccine was introduced). See the research published in The Lancet in October 2016.

Public Health England estimates that the MenB programme has prevented about 250 cases of invasive MenB disease in the last three years. In the second year of the programme, there was an estimated 72% reduction in the number of cases of invasive MenB disease in infants, and in the third year of the programme there was a further estimated 60% reduction in cases of invasive MenB disease in infants.

Is the vaccine safe?

A European study published in 2013 assessed the MenB vaccine when given alongside the 6-in-1 vaccine, a pneumococcal vaccine and a MenC vaccine. The study found that giving the MenB vaccine together with other vaccines did increase the risk of fever and local tenderness at the injection sites. However 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 Hib/MenC vaccine, the HPV vaccine, the 13-valent PCV or flu vaccines.

Page last updated: 
Wednesday, November 28, 2018


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