MenB Vaccine (Meningococcal B Vaccine)

Expand All

This new vaccine was developed to protect against disease caused by MenB (type B meningococcal bacteria), 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 vaccine does not contain any live bacteria and cannot cause meningococcal disease.

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.

Who should have the vaccine?

In the UK the MenB vaccine is given to babies at 8 and 16 weeks, with a booster at 12-13 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 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)

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

The new MenB vaccine in the UK


Bexsero, the MenB vaccine used in the UK, contains different 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 are the building blocks of proteins.)

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.


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 8 and 16 weeks 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 extremely serious but can be treated with adrenaline. Health care workers who give vaccines know how to do this. In the UK between 1997 and 2003 there were a total of 130 reports of anaphylaxis following ALL immunisations. Around 117 million doses of vaccines were given in the UK during this period. This means that the overall rate of anaphylaxis is around 1 in 900,000.

More information on side effects

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.


The MenB vaccine was introduced into the UK schedule on 1st September 2015. The UK is the first country in the world to introduce a MenB vaccine into its routine vaccination schedule. It is expected that 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 .

Before 1999, most cases of meningococcal disease in the UK were caused by MenC infection. A 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.


Meningococcal Septicaemia (MenB) - Charlotte's story

Click here for an accessible text version of this video


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 prevented about 250 cases of invasive MenB disease in the first three years of the programme. 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.


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, January 19, 2022