Impact of pneumococcal conjugate vaccine on pneumococcal disease prevalence and genetics in the UK
Current research
- HPA Centre for Infections, London, UK
- Researchers:
Dr Bruno Pichon, Dr Mary Slack, Dr Rob George, Prof Liz Miller
- Start Date: 19 June 2009
- Type: Lay summary
- View scientific version
Pneumococcal disease is the second most common cause of bacterial meningitis in the UK and Ireland (after Group B meningococcal disease). Conjugate pneumococcal vaccine was introduced into the routine UK infant immunisation programme in 2006. This vaccine protects against the 7 types of pneumococcal bacteria that cause most cases of severe pneumococcal disease - meningitis, septicaemia, and pneumonia - in the UK. It is critically important that the impact of the vaccine on pneumococcal disease is monitored so that we can be sure the immunisation programme is working, and any problems are detected so that changes can be made to deal with them. In the USA, the vaccine was introduced in 2000 and has dramatically reduced disease rates in both young children and adults. However the USA is beginning to see an increase in pneumococcal infections not covered by the vaccine, which may compromise the positive effect of immunisation. This may be due simply to an increase in non-vaccine type pneumococci, or to 'capsule switching' - when bacteria change their outer coating so that the vaccine no longer protects against them.
With the introduction of vaccine, every case of severe pneumococcal disease is now followed up. This enables researchers on this project to conduct molecular examination of the genetic make-up of the pneumococci responsible - including cases judged to be vaccine failures and all cases of meningitis. They will establish whether the bacteria isolated from these patients are non-vaccine types, new emerging types not covered by the vaccine, or vaccine types that have undergone 'capsule switching': exchanged their protective capsule for a different type of capsule that the vaccine cannot recognise. The current "gold standard" method, Multi Locus Sequence Typing, will be used and compared with newer and potentially more cost effective methods. The results obtained will gauge the impact of the pneumococcal vaccination programme and help to inform further strategic development of pneumococcal vaccines and their use in both children and adults.
This project was featured in the Autumn 2006 edition of our newsletter, Microscope. Click to view.
This project was featured in the Edition Two 2008 of our newsletter, Microscope. Click to view.
This project was featured in our 2007 annual review. Click to view.