Informing national and international influenza vaccination policy
Submitting Institution
University College LondonUnit of Assessment
Public Health, Health Services and Primary CareSummary Impact Type
HealthResearch Subject Area(s)
Medical and Health Sciences: Public Health and Health Services
Summary of the impact
Research undertaken at UCL's Centre for Infectious Disease Epidemiology
has provided evidence about vaccination of different groups against
influenza which have influenced policy and practice. In particular, our
work underpins the government's ongoing policy on vaccination of
healthcare workers, and is cited every year in the Chief Medical Officer's
letter to healthcare workers as well as international recommendations on
influenza vaccination of healthcare workers, including widespread
mandatory vaccination programmes in North America. Research on influenza
and acute cardiovascular events has informed US recommendations for
prevention of stroke through vaccination. Recent work also informed the
decision in the UK to extend regular influenza vaccination to children.
Underpinning research
Research led by Dr Andrew Hayward at UCL's Centre for Infectious Disease
Epidemiology, in collaboration with others at Southampton University, the
London School of Hygiene & Tropical Medicine (LSHTM) and the Health
Protection Agency (HPA), has informed national influenza vaccination and
control policy.
Between 2003 and 2005, Hayward designed and led a seminal cluster
randomised controlled trial, funded by the Department of Health (DH) to
encourage influenza vaccination of staff in 44 nursing homes [1].
The study, which involved more than 1,700 healthcare workers and 2,600
residents, showed a significant decrease in patient mortality,
Influenza-like illness (ILI), consultations for ILI with general
practitioners, and ILI hospitalizations during a moderate influenza season
among residents of homes in the healthcare worker vaccination arm,
compared with those residing in control facilities. This provided clear
evidence in favour of vaccinating healthcare workers, which is continually
cited in key communications and international recommendations on this
topic.
Hayward was also part of the team that conducting the only national study
of influenza vaccine attitudes amongst NHS staff [2, 3]. This
DH-funded study among 6,302 NHS staff showed that 19% of responders had
taken up influenza immunisation during winter 2002/3. Amongst those
vaccinated, the majority who accepted vaccination (66%) were most strongly
influenced by the personal benefits of protection against influenza.
Prevention of sickness absence and protection of patients were the prime
motivation for only 10% and 7% of subjects, respectively. Among 3,967 who
declined vaccination, the most common primary demotivators were concern
about safety (31%) and efficacy (29%). 22% were most strongly deterred by
lack of time to attend for vaccination. Free text answers indicated that
37% declined because of a perceived low ratio of personal benefits to
adverse effects. Subjects said they would be persuaded to take up
vaccination in future by easier access (36%), more information about
personal benefit and risk (34%) and more information about effects on
staff absence (24%).
Hayward is lead author in a systematic review and meta-analysis of the
impact of influenza on triggering acute cardiovascular events showing this
is an important preventable risk factor [4].
Since 2006, Hayward has led the MRC/Wellcome Flu Watch study, the world's
largest community study of influenza transmission and immunity. This study
recruited households across England to monitor levels of illness over five
flu seasons, via serological testing of pre- and post-season blood
samples, weekly follow up to record any flu-like illness, and nasal swabs
for those who reported such illness. The main results, which are under
review by the Lancet, provide the most robust measures to date of
influenza burden across different age groups and highlight the
particularly high rates in children [5]. Further results showed
the importance of T-cell mediated immunity in protecting against seasonal
and pandemic influenza.
References to the research
[1] Hayward AC, Harling R, Wetten S, Johnson AM, Munro S, Smedley J, et
al. Effectiveness of an influenza vaccine programme for care home staff to
prevent death, morbidity, and health service use among residents: cluster
randomised controlled trial. BMJ (Clinical Research Ed). 2006 Dec
16;333(7581):1241. http://dx.doi.org/10.1136/bmj.39010.581354.55
[2] Smedley J, Poole J, Waclawski E, Stevens A, Harrison J, Watson J, et
al. Influenza immunisation: attitudes and beliefs of UK healthcare
workers. Occupational and Environmental Medicine. 2007 Apr;64(4):223-7.
http://dx.doi.org/10.1136/oem.2005.023564
[3] Hayward AC, Watson J. Effectiveness of influenza vaccination of staff
on morbidity, and mortality of residents of long term care facilities for
the elderly. Vaccine. 2011 Mar 16;29(13):2357-8. http://dx.doi.org/10.1016/j.vaccine.2011.01.020
[4] Warren-Gash C, Smeeth L, Hayward AC. Influenza as a trigger for acute
myocardial infarction or death from cardiovascular disease: a systematic
review. The Lancet Infectious Diseases. 2009 Oct;9(10):601-10. http://dx.doi.org/10.1016/S1473-3099(09)70233-6
[5] Summary results published online at:
http://www.fluwatch.co.uk/Content.aspx?ContentName=ResultsSummary
(Publication currently under review by the Lancet)
Peer-reviewed funding
Influenza Vaccination of Health Care Workers. Jun 2003-Jun 2005.
Department of Health Policy Research Programme. £139,829.
Flu Watch: Community study of behavioural & biological determinants
of transmission to inform seasonal & pandemic planning. Jul 2006-Dec
2008. Medical Research Council. £1,094,090
Flu Watch 2008. Jul 2007-Jan 2009. Medical Research Council. £1,143,819
Flu Watch Pandemic Extension. Sep 2009-Oct 2012. MRC Wellcome. £2,319,272
Details of the impact
Vaccination of healthcare workers
Hayward's DH Policy Research Programme research on vaccination of
healthcare workers against influenza in nursing homes and acute care
settings has led to national recommendations to immunise staff in nursing
homes and other social care settings [a] and is one of the main
streams of evidence supporting vaccination of healthcare workers against
influenza. Annual campaigns to increase uptake of the vaccination amongst
NHS staff have cited the publication for many years. (See, for example,
the current year's letter from the Chief Medical Officer [b].) The
evidence on low uptake contributed to DH decisions to set up mandatory
routine monitoring of influenza vaccine uptake in England and informs the
content of the DH "Flu Fighters" campaign (launched in 2010/11) aimed at
increasing uptake amongst front line healthcare staff including protection
of patients, safety and effectiveness as key messages. This has led to a
range of local NHS trust campaigns [c]. Since the publication of
our research, healthcare worker vaccination in acute trusts in England has
increased from a steady low of around 15% to around 45% in the 2010/11
season [d].
Internationally, the trial is cited in annual US guidance on healthcare
worker vaccination [e] and has also contributed to 27 States in
the US making healthcare worker influenza vaccination mandatory [f].
Our work was presented as key evidence in a 2013 test-case trial in Canada
on mandatory vaccination [g].
Informing US recommendations of prevention of stroke
Our systematic review and meta-analysis of the influence of influenza as
a trigger for acute vascular events was the first of its kind. It is now
cited in American Heart Association/American Stroke Association guidance
for prevention of stroke, recommending influenza vaccine for all those at
raised risk of stroke [h].
Routine vaccination of children
Our work has also impacted on the recent recommendation by the Joint
Committee on Vaccination and Immunisation (JCVI) of routine vaccination of
all children against influenza every year and the decision not to
recommend extension of vaccination to all adults aged over 50 years. This
decision was largely based on the findings of a dynamic transmission
model, commissioned by the DH and conducted by LSHTM and HPA, to assess
the effectiveness and cost effectiveness of the national influenza
vaccination campaign and consider options for extending this to other
groups. The model predicted that 30% coverage in children would result in
net savings of around £65m and prevent loss of around 17,000 Quality
Adjusted Life Years annually. The model also suggested that extending
vaccination to all those aged greater than 50 years would not be cost
effective [i].
In order to increase confidence in the findings of the economic model the
committee requested that the age specific baseline levels of infection and
disease inferred by the model be validated against Flu Watch data
(provided prior to publication) to check that the model provided an
accurate representation of the true community burden. The fact that model
output and the empirical measures from Flu Watch matched gave confidence
in the validity of the model and thus supported the recommendation to
extend routine influenza vaccination to children but not to all adults
aged over 50. In deliberating on the type of vaccine to be used the Flu
Watch finding that cellular immune responses provide protection against
both seasonal and pandemic disease was discussed and contributed to the
decision to use Live Attenuated Influenza Vaccine (which stimulates both
cellular and humoral immunity) rather than Trivalent Inactivated Vaccine
(which only stimulates humoral immunity) [j]. The childhood
vaccination campaign is being launched in test regions in 2013.
Sources to corroborate the impact
[a] Immunisation Against Infectious Disease — The Green Book
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/147958/Green-
Book-Chapter-19-v4_71.pdf
[b] CMO letter detailing 2012-3 campaign to vaccinated NHS staff against
influenza:
https://www.gov.uk/government/publications/the-flu-immunisation-programme-2012-13
[c] National NHS staff seasonal flu vaccination campaign 2013/14 Flu
fighter communications toolkit — for use by communications teams in NHS
organisations.
http://www.nhsemployers.org/SiteCollectionDocuments/NHS%20Flu%20fighter%20communic
ations%20toolkit%20for%202013-14.pdf, Royal Free local campaign —
Flu Show — Flu Fighter Campaign Video. http://www.youtube.com/watch?v=YoNyxceDMLg&feature=related
[d] Seasonal influenza vaccine uptake amongst frontline healthcare
workers (HCWs) in England Winter season 2010/11 (p 44)
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/216394/dh_129
857.pdf
[e] MMWR — Prevention and Control of Influenza with Vaccines.
Recommendations of the Advisory Committee on Immunization Practices
(ACIP), 2010 Early Release, July 29, 2010
http://www.cdc.gov/mmwr/preview/mmwrhtml/rr59e0729a1.htm?s_c
[f] Stewart AM, Cox MA. State law and influenza vaccination of health
care personnel. Vaccine. 2013 Jan 21;31(5):827-32. http://dx.doi.org/10.1016/j.vaccine.2012.11.063
[g] Letter from Vice President Public Health Chief Medical Health
Officer, Fraser Health Authority highlighting role of our research on
Canada Test Case regarding mandatory health care worker vaccination. Copy
available on request.
[h] AHA/ASA Guideline Guidelines for the Primary Prevention of Stroke. A
Guideline for Healthcare Professionals From the American Heart
Association/American Stroke Association. Stroke. 2011; 42: 517-584 http://dx.doi.org/10.1161/STR.0b013e3181fcb238
[i] Baguelin M, Flasche S, Edmunds J. The cost-effectiveness of
vaccination against seasonal influenza in England. 2012. Copy available on
request.
[j] JCVI statement on the annual influenza vaccination programme —
extension of the programme to children. 25 July 2012. Copy available on
request.