Vaccination catch-up campaign in response to recent increase in invasive Hib infection in the United Kingdom – implications for the rest of Europe?

A catch-up immunisation campaign against Haemophilus influenzae type b (Hib) is scheduled to commence in England and Wales in the second week of May (http://www.doh.gov.uk/cmo/letters/cmo0301.htm). This decision has been made in response to a recent increase in invasive infections due to this organism, with 145 cases of confirmed Hib disease reported in children under five in England and Wales last year. While this is still far lower than the 773 cases observed in this age group in 1990, before routine immunisation was implemented, it is a dramatic rise from the nadir of 22 in 1998 (1). To the end of 2001, surveillance in several European Union (EU) countries indicated that this experience was unique to the United Kingdom (UK) (http://www.phls.org.uk/inter/eu_ibis/aims.htm). A more recent report of a rise in cases in the Netherlands in 2002 is cause for concern (2).