It is essential to continue to study vaccines after they have been licensed for use in the population. This includes monitoring their effectiveness when given to all sectors of the public, and ensuring that they are safe (including identifying any vary rare side effects that might only become apparent when the vaccine has been given to very large numbers of individuals or over a long period of time). It is also important to assess who gets the vaccine, to help plan interventions to address any vaccine-related health inequalities.
Much of the vaccine research we do is carried out jointly with colleagues at Public Health England and with other key collaborators as part of the NIHR Health Protection Research Unit (HPRU) in Immunisation. Within the HPRU, the Electronic Health Records Theme aims to use linked electronic health records, other routine data, and innovative methods to support Public Health England’s programme of work on vaccines.
One aspect of our HPRU work is to use linked electronic health data to investigate the changing burden of vaccine-preventable disease. We do this both for diseases for which vaccines have not yet been introduced in the UK (to help inform decisions about whether to introduce a vaccine), and for diseases for which a vaccine is already available (to monitor the impact of vaccination on disease frequency). Examples of this work include:
- assessing the impact of introducing infant rotavirus vaccination on the incidence of acute gastroenteritis in children and in adults
- monitoring changes over time in the frequency of chickenpox seen in general practice in the UK, to help support decision-making by the UK Joint Committee on Vaccination and Immunisation on whether to introduce chickenpox vaccination
Our HPRU vaccine uptake work has involved developing methods to identify social factors in linked anonymised electronic health data. We are using these methods to investigate factors associated with lower uptake of vaccines in children, in older individuals and in pregnant women.
Examples of our HPRU vaccine safety work include:
- use of electronic health records to conduct near “real-time” vaccine safety surveillance, for early detection of rare side effects in newly introduced and re-formulated vaccines. We have examined near real-time surveillance systems in existence world-wide, and we are now assessing the feasibility of implementing such a system in the UK.
- investigations of the safety of vaccines given in pregnancy, for women and their unborn children.
Our research group also has a long track record of investigating vaccines and vaccine preventable diseases outside of our HPRU work. A key study was the use of electronic health records to demonstrate the safety of MMR vaccine in relation to autism, which helped to restore public confidence in the vaccine. More recent work includes assessing the vaccine effectiveness of the shingles vaccine in routine use, and studies to show that a range of vaccine-preventable infections (such as influenza, pneumonia, chickenpox) can trigger acute cardiovascular events such as heart attacks and strokes (see our Cardiovascular Disease page).