Each autumn brings with it the usual newspaper predictions that a duck sneezing in the Far East heralds an apocalyptic flu pandemic. As a nation, are we suffering from a bad case of flu fatigue?

Jokes about ‘man flu’ and confusing influenza with a bad cold can be amusing but they do trivialise a potentially lethal disease. Public Health England estimates that flu caused 16,415 extra deaths during the 2014/15 season in England and Wales. That is more than the death toll for both breast and prostate cancer.

Yet the yearly warnings that the next pandemic is imminent can make a real and present danger seem like a vague, distant hazard, such as those exemplified by global warming or the impact of a near earth object. Flu fatigue can breed complacency and contribute to poor vaccine uptake. More than a quarter (27.3 per cent) of people over 65 years of age did not receive a flu jab in 2014/15.

Half (49.7 per cent) of those aged six months to under 65 years of age with one or more risk factors and a similar proportion of frontline health workers (45.1 per cent) also went unvaccinated.¹ With community pharmacists in England now able to vaccinate eligible patients as part of a national service, they are ideally placed to help drive vaccine uptake.

Stroke risk

Reminding the public that the benefits of vaccination extend beyond the respiratory tract may help counter flu fatigue. For example, experiencing a respiratory infection within the previous week or month tripled or doubled (odds ratio [OR] 2.91 and 2.41 respectively) the risk of suffering an ischaemic stroke.²

Researchers from the University of Lincoln have examined the records of 17,853 stroke patients to compare the incidence of cerebrovascular events up to 180 days after immunisation with a baseline when patients were unprotected. Stroke risk fell by 36 per cent in the four to seven days after vaccination, by 30 per cent at eight to 14 days, 24 per cent at 15-28 days and 17 per cent at 29-59 days.3 Interestingly, stroke risk was 45 per cent lower in the 14 days before vaccination and 55 per cent lower in the first one to three days after vaccination.

These reductions are, however, probably artefacts. The apparent risk reduction in the 14 days before vaccination might arise because patients are less likely to receive a flu jab immediately after stroke or late entry of vaccination data.³ Flu jabs produce protective antibody titres in about 59 per cent of recipients within one week of vaccination,⁴ so the reduction in risk in the one to three days after vaccination is probably too soon for a protective immunological response.

Such a reduction might arise because individuals with prodromal symptoms, or at immediate high risk of stroke, may have been less likely to attend for their flu jab. Such artefacts might apply, to a degree, to the reduced risk four to seven days after vaccination. The vaccine, however, could confer immunity by this time.³

Stronger response

Having a jab early in the flu season (between September 1 and November 15) produced a stronger protective response than later vaccination. The stroke risk eight to 14 days and 15-28 days after vaccination declined by 30 and 24 per cent respectively in those who received early vaccination. The 16 per cent fall and 18 per cent increase in stroke risk in the late vaccination group (eight to 14 days and 15-28 days after vaccination respectively) were not statistically significant.³

Protection against stroke is therefore another reason for community pharmacists to stress the importance of early vaccination. “The findings, which could amplify community health staff advice to the public, support current recommendations for flu vaccination in people at high risk, but with the possible added benefit of stroke prevention,” comments Niro Siriwardena, professor of primary and pre-hospital health care at Lincoln University.

“We are now at the point of developing further studies into whether it could be recommended to extend vaccination to younger adults at risk of stroke. “If a causative link between influenza vaccination and reduction in stroke risk is confirmed by experimental studies, and if this leads to higher vaccination rates, there would be significant benefits for patient and population health.”

Cost-effective

The benefits of immunisation go beyond health – vaccination is highly cost-effective. The influenza programme targeting at-risk patients and the elderly in England and Wales realised a net benefit of £253m a year according to a new analysis. Extending vaccination to any low-risk group, especially if the programme vaccinates schoolchildren, is likely to be cost-effective.⁵

Apart from protecting children directly, extending the vaccination programme would provide “indirect protection by lowering flu transmission from children to other children, adults and to those in the clinical risk groups of any age, thus averting many cases of severe flu and flu-related deaths in older adults and people with clinical risk factors”.⁶ So, during the 2015/16 flu season, children who were two, three and four years old on August 31, 2015, and all year one and year two school age children, will be offered the vaccine.⁶

Pharmacists can help by explaining the programme to parents – immunisations always seem to trigger concerns – and encouraging immunisation more generally, even if it is not a service they offer themselves. It is easy to forget that even non-pandemic flu kills more people than many common cancers.

Increasing uptake is central to realising vaccination’s unequivocal benefits: vaccine efficacy is around 73 per cent in those years when the vaccine is well matched to the circulating strains,⁵ while vaccinating children drives herd immunity. With the introduction of a national flu vaccination service in England, community pharmacists are ideally placed to drive vaccine uptake and help tackle flu fatigue.

 

 

Protection against stroke is another reason for community pharmacists to stress the importance of early vaccination