Over the past 20 years, evidence has accumulated that occupations entailing exposure to metal fume (principally welders) are at increased risk of developing and dying from pneumococcal and unspecified lobar pneumonia.1–9 The hazard is apparent in people working with ferrous metal,2 ,4 may extend to other metals4 and is reversible following cessation of exposure.1 ,4 ,5 There are indications that the ultrafine particles in welding fume promote adherence of pneumococci to bronchial epithelium,10 but the underlying mechanisms are not yet well established. Nevertheless, in 2011, the independent Joint Committee on Vaccination at the English Department of Health (DH) judged that the evidence of increased risk was sufficient to recommend that employers offer welders vaccination against pneumococcus.11 This was a new measure that had not previously been applied in other countries.

Subsequently, on the advice of the UK Health and Safety Executive (HSE), the DH weakened its recommendation, stating only that vaccination ‘should be considered for those at risk of frequent or continuous occupational exposure to metal fume (e.g. welders), taking into account the exposure control measures in place’.12 Then after some delay, HSE published guidance for employers in which they were advised to …