Measuring immunity to meningococcal Y and W135 bacteria in England and Wales
Establishing a baseline for immunity.
Dr Caroline Trotter, Dr Helen Findlow, Professor Ray Borrow
- Start Date:
01 November 2012
Health Protection Agency North West, Vaccine Evaluation Unit, Manchester, UK
What is this project about?
We do not know what proportion of people have antibodies that protect them against meningococcal disease caused by group Y and W135 bacteria. Serological surveillance – measuring immunity to disease in a representative sample of the population – has been used to inform vaccine policy for several diseases, including meningococcal C. It is important to establish a baseline for immunity against meningococcal Y and W135. In our study, we will use serum from the blood samples routinely collected by the Health Protection Agency for national surveillance of the immunisation programme. We will determine the levels of antibody in these samples that can kill groups Y and W135 and define the percentage of people who are protected against disease in each age group.
Why is this important?
This information is important because it will help us to understand the patterns of disease we observe and investigate the potential usefulness of new ACWY vaccines in the UK.
The United Kingdom was the first country to introduce the meningococcal C vaccine, in 1999, incorporating it into the childhood immunisation schedule and performing a catch-up campaign offering the vaccine to all those aged less than 18 years, and eventually to everyone under 25. Since then the numbers of group C cases have declined dramatically.
A meningococcal conjugate vaccine that protects against groups A, C, W135 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 W135 disease could make it much more useful as routine vaccine, which could be used in place of 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, W135 (and serogroup A which causes epidemic meningitis in Africa).
Although there are currently few cases of meningitis and septicaemia due to groups Y and W135 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
). Group W135 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.
This project will provide valuable information for vaccine researchers, those involved in setting UK immunisation policy, and the vaccine industry.