MenACWY is a conjugate vaccine (see our page on 'Types of vaccine'). Sugars (polysaccharides) are taken from the capsule around the meningococcal bacteria and joined to a non-toxic protein from diphtheria (called CRM197) or from tetanus. 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 main aim of giving this vaccine is to protect young people against four different types of meningococcal disease. Those aged 15 to 19 are more at risk from meningococcal disease than any other age group, except the under 5s.
However, it is expected that vaccinating this age group will also offer herd protection against MenW and MenC disease for the rest of the population, including infants. This is because teenagers and young adults are the main carriers of meningococcal bacteria, which are carried at the back of the nose and throat. People who are immunised can no longer carry the bacteria and pass them on to others in the population.
To achieve herd protection a high proportion of young people need to be vaccinated.
In October 2018 the Joint Committee on Vaccination and Immunisation (JCVI) issued a statement outlining the importance of improving vaccine uptake in 18-25 year olds who have missed out on MenACWY vaccination. Across childhood vaccines, the target in the UK for vaccination coverage is 95%.
At just under 80% for children in school year 10, MenACWY coverage for 2021 to 2022 is not yet back up to pre COVID-19 pandemic levels when it stood at almost 87% for that year group.
As well as teenagers and young people, the MenACWY vaccine is also recommended for travellers to parts of the world which are high risk for meningococcal disease. This includes 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. When required for travel, the MenACWY vaccine is not provided free of charge if you are over the age of 25.
Does the vaccine work?
Since the introduction of the different vaccines against meningococcal disease from 1999, there has been a large decline in the number of cases. And recent modelling suggests that the disease will eventually be eradicated in the UK as a result of the vaccination programme.
UK Health Security Agency data show that in England confirmed cases of meningococcal disease peaked at 2,595 cases in 1999 to 2000 before a steep decline. There were just 205 confirmed cases for 2021 to 2022, although the lockdowns and social distancing measures of the COVID-19 pandemic have affected these figures.
The incidence of meningococcal disease has decreased from 2 per 100,000 in 2006 to 2007, to 1 per 100,000 in 2011 to 2012. It is currently below 1 per 100,000.