Meningitis B Vaccine

What is meningococcal disease?

Meningococcal disease is a serious illness caused by the bacteriaNeisseria meningitidis. This bacterial infection can cause meningitis (inflammation of the lining around the brain) and septicaemia (blood poisoning).

How does meningococcal B (MenB) vaccine work?

MenB vaccine contains extracts from the meningococcal B bacteria. The vaccine works by making the body's immune system respond to the bacteria, without causing disease.

How long is the incubation period for meningococcal B disease?

an incubation period which is typically 1-10 days, although usually less than four days.

What are the symptoms of meningococcal disease?

The onset of meningococcal disease can be very quick. The symptoms of meningococcal disease include fever, stiff neck, headache, joint pains, and a rash. If you think your child or baby has signs of meningococcal disease get medical help immediately from your G.P. or nearest paediatric Emergency Department. In some cases acting quickly to get medical help can mean the difference between life and death.

Meningococcal disease is a very serious life threatening illness.

Of the people who get meningococcal disease:

  • 1 in 20 will die
  • 1 in 10 people who recover will have a major disability such as deafness, brain damage or loss of fingers, toes, hands, feet, arms or legs.

Early diagnosis leads to early treatment with antibiotics and a greater chance that the person will make a full recovery. Early diagnosis is the key so if you suspect that someone may have meningitis or septicaemia seek medical attention immediately.

What are the side effects of MenB vaccine?

MenB vaccine is well tolerated by most babies and has a very good safety profile. The following are side effects which have been noted with this vaccine. Please see patient information leaflet (PIL) for full details available at

Very Common (1 in 10 babies)

  • Fever (>38C)
  • Tenderness / pain at injection site
  • Skin rash
  • Irritable
  • Vomiting / diarrhoea
  • Unusual crying

Uncommon (1 in 100 to 1 in 1000 babies)

  • High fever (>40C)
  • Seizures (including febrile seizures)
  • Eczema

Rare (1 in 1,000 to 1 in 10,000 babies)

  • Urticaria

Kawasaki's disease

What is the pattern of fever expected after MenB vaccine?

Ibuprofen is not recommended.

Fever after MenB vaccine follows a predictable pattern. The fever rises over the first 6 hours and peaks at this point. It then decreases over 24 hours, when most fevers will be gone. By 36 hours post vaccination very few babies would be expected to still have a persisting fever.

Evidence has shown that if parents are told about the possibility of fever and give paracetamol (most particularly the first dose) then very few parents medically present because of their baby's fever.

How much paracetamol should be given to babies?

Babies at their 2 and 4 month vaccine should receive 2.5ml (60mg) of liquid infant paracetamol.

Liquid infant paracetamol Dosage 2 month visit 4 month visit
(120mg / 5 ml)
Dose 1 2.5ml At the time of injection At the time of injection
Dose 2 2.5ml 4-6 hours after dose 1 4-6 hours after dose 1
Dose 3 2.5ml 4-6 hours after dose 2 4-6 hours after dose 2

Should paracetamol be given before vaccination?

It is important that babies are not given paracetamol prior to vaccination, as the GP or practice nurse will need to be able to assess that the baby is well to receive the vaccines.

How effective is MenB vaccine?

MenB vaccine has been shown to very effective at producing an immune response to the particular strains of meningococcal B causing invasive meningococcal disease in Ireland. Research has suggested that up to 88% of meningococcal B strains should be protected by MenB vaccine.