Skip to main content

MenB vaccine

The MenB vaccine helps protect against meningococcal group B bacteria that can cause serious illnesses, including meningitis and sepsis. It's given to children when they're 8 weeks, 16 weeks and 1 year old.

What the MenB vaccine is for

The MenB vaccine helps protect children against bacterial infections caused by meningococcal group B bacteria (MenB).

MenB can cause serious illnesses, including:

  • meningitis (an infection in the brain and spinal cord)
  • septicaemia (blood poisoning)
  • sepsis (a life-threatening reaction to an infection)

When children should have the MenB vaccine

Children are offered 3 doses of the MenB vaccine as part of the NHS vaccination schedule.

They're offered the vaccine with other routine vaccines at:

  • 8 weeks old
  • 16 weeks old
  • 1 year old

It's best to have the MenB vaccines on time so children are protected when they're most at risk of getting MenB illnesses.

But if your child has missed any of their MenB vaccines, contact their GP surgery. They can still have the MenB vaccine up to the age of 2.

Children who cannot have the MenB vaccine

Most children can have the MenB vaccine.

They only reasons they cannot have the vaccine are if either:

  • they've had a serious allergic reaction (anaphylaxis) to a previous dose of the vaccine
  • they've had a serious allergic reaction to an ingredient in the vaccine

Getting vaccinated if your child is unwell

Your child can have the MenB vaccine if they're unwell but they do not have a high temperature.

If your child has a high temperature, wait until they're feeling better before having the vaccine.

MenB vaccine ingredients

There is 1 type of MenB vaccine routinely given to children in the UK. You can check the ingredients in the patient leaflet:

Bexsero MenB vaccine patient leaflet (Electronic Medicines Compendium website; PDF only, 140KB)

How to get the MenB vaccine

Your GP surgery will usually contact you about your child's MenB vaccinations. This will usually be by letter, text, phone call or email.

It's best to have the vaccinations on time, but your child can still have the MenB vaccine up to the age of 2.

Non-urgent advice: Speak to your GP surgery if:

  • you have not been contacted to get your child's MenB vaccinations
  • your child has missed their MenB vaccinations, or you're not sure if they've had all 3 doses of the vaccine
  • your child is unwell with a high temperature and is due to have the MenB vaccine – they'll need to wait until they're feeling better before having the vaccine
  • you need to change a vaccination appointment

Your GP surgery can book or rearrange an appointment.

Side effects of the MenB vaccine

Like all medicines, the MenB vaccine can cause side effects, but not all children get them.

Common side effects of the MenB vaccine include:

  • swelling or pain where the injection was given
  • a high temperature
  • feeling tired or irritable
  • loss of appetite
  • diarrhoea

These side effects usually get better within 1 or 2 days.

To help prevent or treat a high temperature, it's recommended you give your baby child's paracetamol after their MenB vaccinations at 8 weeks and 16 weeks old.

You'll need to give your baby 3 doses of paracetamol. Give them 1 dose as soon as possible after being vaccinated, give them a 2nd dose 4 to 6 hours later, and a 3rd dose 4 to 6 hours after that.

Make sure you leave at least 4 hours between each dose and do not give them more than 4 doses in 24 hours.

Urgent advice: Ask for an urgent GP appointment or call NHS 111 if your child:

  • is under 3 months old and has a temperature of 38C or higher, or you think they have a high temperature
  • is 3 to 6 months old and has a temperature of 39C or higher, or you think they have a high temperature
  • still has a high temperature more than 48 hours after having their MenB vaccination
  • is unwell and you're worried about them

Allergic reactions

More serious side effects such as a severe allergic reaction (anaphylaxis) are very rare and usually happen within minutes.

The person who vaccinates your child will be trained to deal with allergic reactions and treat them immediately.

How well the MenB vaccine works

The MenB vaccine works very well at protecting children against most types of meningococcal group B bacteria in the UK.

Research has shown that the vaccine is very effective at preventing illnesses caused by these bacteria.

Before the MenB vaccine was introduced, meningococcal group B bacteria were the biggest cause of meningitis and sepsis in the UK.

Since the vaccine has been used in the UK, there has been a big drop in the number of young children getting MenB illnesses.

The MenB vaccine does not protect against other causes of meningitis and sepsis, so it's still important to be aware of the symptoms.

Page last reviewed: 13 March 2024
Next review due: 13 March 2027