Measuring immunity to meningococcal Y and W135 bacteria in England and Wales

Establishing the baseline immunity.

Scientific version
  • Researchers:
    Dr Caroline Trotter, Dr Helen Findlow, Professor Ray Borrow
  • Start Date:
    01 July 2010
  • Category:
  • Location:
    Health Protection Agency North West, Vaccine Evaluation Unit, Manchester, UK
Measuring immunity to meningococcal Y and W135 bacteria in England and Wales
Completed September 2011

Measuring immunity to disease in a representative sample of the population has been used to inform vaccine policy for several diseases, including meningococcal C. But prior to this project, it wasn’t clear how many people had antibodies that protected them against meningococcal disease caused by group Y and W bacteria.

Blood samples collected from individuals of all ages in 2009 were obtained from the Health Protection Agency Seroepidemiology Unit, which collects samples from participating laboratories across the country. A test which looks at how many bugs are killed by the person’s blood (termed the Serum Bactericidal Antibody (SBA) assay) was used to find out how many people have immunity to meningococcal Y and W bacteria and whether there are any differences in people of different ages. 

What is meningococcal Y or meningococcal W disease?

There are several groups of meningococcal bacteria (A,B,C,W135,Y and Z). In the past 50 years, most meningococcal disease in the UK and Ireland has been due to MenB and MenC, while other groups have dominated in other parts of the world.

You can read more about meningococcal disease on our information pages

Who this project will help

Edward Bright

Meningococcal disease

An inspiration to all who meet him.

» Read this story

Why is this important?

This information is important because it helps us to understand the patterns of disease we observe and investigate the potential usefulness of new ACWY vaccines in the UK.

A meningococcal conjugate vaccine that protects against groups A, C, W and Y was licensed in Europe early in 2010. Although it is unclear how this vaccine will be used in the UK except as a travel vaccine, a rise in group Y or W disease could make it much more useful as routine vaccine, which could be used in place of the MenC vaccine in the childhood immunisation schedule. Alternatively it may be used in adolescence to boost immunity to meningococcal C and provide protection against meningococcal Y, W (and serogroup A which causes epidemic meningitis in Africa). 

Although there are currently few cases of meningitis and septicaemia due to groups Y and W in the UK, disease due to these bacteria is more common in other countries and cases could potentially increase. In the US, the proportion of meningococcal cases caused by serogroup Y increased from 2% at the beginning of the 1990s to 37% at the end of that decade. Although still rare here, Group Y disease is rising as is carriage of the bacteria (see poster from Dr C. Bayliss at MRF conference). Group W is normally not a major cause of disease in the UK, but caused outbreaks here and around the world, associated with the Hajj pilgrimage to Mecca in 2000 and 2001. 


Overall 18.4% and 19.6% of subjects were protected against types W135 and Y, respectively. Antibody prevalence varied by age. In general, levels were low in younger children with 7% and 13% of children under 5 years protected against types W135 and Y, respectively. Antibody levels peaked in 20-24 year olds for type W135 and in 30-44 year olds for type Y. Unlike antibody studies against type B meningococci, there was not an obvious peak of antibody in teenagers. Naturally occurring antibodies against types W135 and Y meningococci in England appears to be low.

Papers and presentations

Scientific results are shared with other doctors and scientists through scientific journals (papers) and presentations at conferences.

This work has been presented at:

Poster P036 entitled “Seroprevalence of serum bactericidal antibodies against group W135 and Y meningococci in England in 2009”

It has also been published in the journal “Clinical Vaccine Immunology”

Trotter C, Findlow H, Borrow R