MenACWY Vaccine (Meningococcal group A, C, W-135 and Y conjugate vaccine)

Key vaccine facts

This vaccine gives protection against four types of meningococcal disease caused by groups A, C, W and Y (MenA, MenC, MenW and MenY). Meningococcal disease is a major cause of meningitis and septicaemia.

The MenACWY vaccine is given to teenagers and new university students in the UK as part of the routine NHS schedule. It replaced the dose of MenC vaccine which was previously given to teenagers and also to student freshers. These changes were made in summer 2015 because of the recent increase in cases of MenW disease in the UK (see 'More information about the vaccine' below). It is expected that vaccinating this age group will offer herd protection against MenW for the rest of the population, including infants.

The MenACWY vaccine is offered to all 17-18 year olds, and to student freshers up to the age of 25 (all those starting university between 2015 and 2017). Since autumn 2015 the MenACWY vaccine has been given to teenagers in year 9 or 10 in place of the MenC booster vaccine.

The vaccine boosts protection against MenC disease and also protects against MenA, MenW and MenY meningococcal disease. One dose of the vaccine offers very good protection. It has been used for many years as a travel vaccine and has an excellent safety profile.

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

The vaccine can safely be given at the same time as the Teenage Booster vaccine.

The MenACWY 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 MenACWY vaccine may contain very small amountsof these ingredients:

  • Sucrose (sugar), used as a stabiliser
  • Sodium chloride (salt)
  • Other harmless sodium and potassium salts used as acidity regulators during the manufacture of the vaccine
  • Trometamol, another acidity regulator used during the manufacture of the vaccine

MenACWY is a conjugate vaccine. Sugars are taken from the capsule around each of the four different types of the bacteria, and joined to a non-toxic protein from tetanus or diphtheria. The protein helps to stimulate the immune system in a broader way to respond well to the vaccine. This gives a better immune response in individuals of all ages.

The MenACWY vaccines used in the UK do not contain the preservative thiomersal (mercury).

Side effects

Very common side effects (affecting more than 1 in 10 people)

  • Pain, redness and swelling at the injection site
  • Headache
  • Feeling tired, irritable or sleepy
  • Feeling generally unwell
  • Loss of appetite
  • Fever

Common side effects (affecting between 1 in 10 and 1 in 100 people)

  • Stomach upsets (such as feeling sick, diarrhoea or vomiting)
  • A hard lump or a large amount of redness and swelling at the injection site
  • Rash
  • Muscle or joint pain

Uncommon side effects (affecting between 1 in 100 and 1 in 1000 people)

  • In babies: crying or sleeplessness
  • Dizziness
  • Loss of feeling, warmth or itching at the injection site

Rare (affecting between 1 in 1000 and 1 in 10000 people)

  • Swelling of the injected limb
  • Febrile convulsions (fits)

Many of the common symptoms can be relieved by giving paracetamol or ibuprofen.

It is quite common for teenagers to have panic attacks before vaccination, or to faint during vaccination. These should not be confused with reactions to the vaccination itself.

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 about the vaccine

There have been a number of changes to the schedule for meningococcal vaccines in the last few years. A teenage MenC booster was introduced in 2013, and a booster for student freshers in 2014. Both of these were replaced by the MenACWY vaccine in 2015.

These changes have been made because of the recent increase in cases of MenW disease in the UK. Overall, the number of cases of meningococcal disease has been falling in the UK since the MenC vaccine was introduced in 1999, but disease caused by MenW is on the increase in the UK. In 2014/15, 176 confirmed cases of MenW disease were reported in the UK across all age groups. See more information from Public Health England and our blog post from March 2015.

Following introduction of the MenC vaccine in 1999, the number of cases of meningococcal disease caused by group C bacteria fell by over 90% in vaccinated groups:

The MenACWY vaccine is also recommended for travellers to parts of the world which are high risk for meningococcal disease (including parts of Africa and Saudi Arabia). All visitors to the Hajj and Umrah pilgrimages in Saudi Arabia need proof that they have been vaccinated against type A, C, W and Y meningococcal disease. Travel vaccines are not provided free of charge.

Does the vaccine work?

Since the Men ACWY programme started, there has not been a case of MenA, MenC, MenW or MenY disease in a vaccinated teenager in the UK.

Page last updated: 
Thursday, April 20, 2017


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