Title: Pandemic Influenza: Population susceptibility, severity and spread. Rapid Research using the Health Survey for England (HSE)
Funder: Department of Health and Social Care

Abstract: Project Title: Pandemic Influenza: Population susceptibility, severity and spread. Rapid Research using the Health Survey for England (HSE) Scientific Abstract: Design. Serial cross sectional serological prevalence surveys with retrospective ascertainment of vaccination and respiratory illness history in conjunction with the National Health Survey for England (HSE). Setting. Community household setting across England. Target population. Households participating in the Health Survey for England (HSE). Technology being assessed. Use of HSE as a rapid means of determining population level immunity, severity and spread through the first two waves of a pandemic. Measurement of outcomes. Antibody response to influenza strain of interest in vaccinated and unvaccinated individuals. Measurement of population rates of clinical influenza-like-illness. National hospitalisation and case fatality rates. Phase 1 - Retrospective Validation of 2010 population level clinical illness rates derived from HSE by comparison with MRC/Wellcome Flu Watch study (March - June 2014). N= 2952 Phase 2 - Pilot of specimen and data collection alongside HSE (already happened October 2012 - April 2013) and the analysis and reporting of the data (July 2013 - March 2014). N=3216 Phase 3 - Holding phase - project ethically approved each year but only triggered in the event of a pandemic. Phase 4 - Real time monitoring through the first two phases of a pandemic - repeat methodology for phase 2 to provide rapid estimates of severity and spread and monitor through the pandemic. N= 4000 Expertise. UCL and National Centre for Social Research - Unparalleled expertise in population survey methodology and large scale serological studies. Impact. Early measures of age specific severity and spread of infection will allow targeting of vaccines, antivirals and non-pharmaceutical interventions and enable response to be proportionate to severity.

Lay abstract: The next influenza pandemic will arise suddenly and with little warning. Pandemic influenza can be severe with high death rates or, as was seen in the last pandemic, the strain may be relatively mild with low hospitalisation and death rates. Governments need information on the severity of influenza early in a pandemic to help them decide how much pandemic vaccine and antivirals to order. They need to regularly reassess the situation to decide how best to use these antivirals and vaccines throughout the pandemic. Measuring severity needs large studies to look for evidence of infection in blood samples and to ask people about their illnesses. Research on such a large scale usually takes many months to set up but in a pandemic results are needed much more quickly than this. This research is designed to overcome this problem by working alongside a very large national survey which already takes place every year -The Health Survey for England. This survey is one of the most important ways we have of monitoring the health of the general public. It involves research nurses visiting households across the country throughout the year to collect detailed health data and to take blood samples (for tests such as cholesterol levels). We will add simple questions (about influenza like illness and vaccination) and take an additional blood sample (to look for evidence of influenza infection) so that we can rapidly measure the severity of a new strain of influenza as soon as it starts to spread. The additional blood specimen uses the same needle as the sample that is already being taken and therefore will result in minimal additional discomfort to the participants. Making this a routine part of a survey that is already running means that the additional cost per participant is minimal and that in a pandemic where time is of the essence, the delays needed to plan the study, get ethical and organisational approvals, and to train staff can be avoided. The research team includes scientists from University College London, Public Health England and representatives from the Health Survey for England. We have extensive experience of running national surveys to measure the level of influenza in the community and using the results to influence national decision-making. The costs relate to: 1) The regular collection of additional blood samples and questions alongside the Health Survey for England. 2) Laboratory analysis of the blood specimens to look for evidence of influenza infection. These tests will only be conducted during pilot periods (when we are testing out methods) and during a pandemic. 3) Statistician time to develop and run analyses and to ensure that these can be automated to allow real-time reporting of results. In summary this research will allow us to measure the severity of a new strain of influenza rapidly, accurately, and at the lowest possible cost and will inform important national decisions about the purchase and use of vaccines and antivirals.

Research activity codes: 4.3 INFLUENCES AND IMPACT;4.4 POPULATION SCREENING
Health categories: INFECTION