This guidance is aimed at occupational physicians responsible for the care of workers outside the health and social care sector.
Over 200 viruses cause influenza-like illness (ILI). In mild disease, symptoms of influenza generally last less than a week, though can last up to two weeks. While serious illness is unusual in healthy adults, those with underlying conditions or who are pregnant are more likely to suffer significant complications.
The virus strains in seasonal vaccines are those expected to circulate in the next season, according to World Health Organization (WHO) recommendation. The strain matching is generally good, for example the 2013/14 mid-year estimate for all strains in the trivalent vaccine was 61%, with meta-analysis showing that in seasons with an effective vaccine the average efficacy was 59%. However, genetic drift and genetic shift in the virus is unpredictable, which results in an unmatched strain in some years. WHO recommend continuation of immunisation campaigns even if there is a strain mismatch.
The Joint Committee on Vaccination and Immunisation (JCVI) concluded in 2011, after considering all the data, that raising vaccine uptake in over 65s and at-risk groups would be most beneficial.
Considering that influenza is a time-limiting illness, the WHO recommends annual seasonal immunisation for people at higher risk of serious complications such as pregnant women, children aged 6 months to 5 years, individuals with specific chronic medical conditions, the elderly and healthcare workers.
The BMA's position is that:
- Influenza immunisation can reduce the rates of illness and lost work days in healthy adults in years when there are high levels of influenza activity and a good match between vaccine strain and circulating strain
- It is not recommended to offer annual seasonal influenza immunisation to employees who do not work in health or caring roles, or other specific occupational groups as occasionally defined by the respective Chief Medical Officer's letter
- Employees in targeted immunisation groups, such as the elderly or those in clinical risk groups should be encouraged to be immunized for seasonal influenza
- It may be appropriate to encourage some workers to have influenza immunisation. Considerations include:
Occupational physicians should work with employers to ensure immunisation is offered to employees for whom a risk assessment has identified a risk of exposure eg laboratory workers working with influenza virus.
- A high level of influenza activity is reported by UK government public health agencies
- Key workers in whom absence would cause significant service disruption
- Business travelers - there is a low but measurable increased risk from air travel
Download the full position statement (PDF, August 2015)