Infant fever trends following the launch of the meningococcal B vaccine in the UK
Authors: Harcourt Sally , Morbey Roger , Bates Chris , Carter Helen , Ladhani Shamez , Elliot Alex J. , Smith Gillian E. 
Published: May 2017

ObjectiveTo use syndromic surveillance data to assess whether there hasbeen an increase in GP fever consultations since the inclusion of themeningococcal B (MenB) vaccine in the UK vaccination schedule.IntroductionFrom 1 September 2015, babies in the United Kingdom (UK)born on/after 1 July 2015 became eligible to receive the MenBvaccine, given at 2 and 4 months of age, with a booster at 12 months.1Early trials found a high prevalence of fever (over 38°C) in babiesgiven the vaccine with other routine vaccines at 2 and 4 months.We used syndromic surveillance2data to assess whether there hadbeen increased family doctor (general practitioner (GP)) consultationsfor fever in young infants following the introduction of the vaccine.MethodsGP consultations for fever in infants aged under 1 year wereextracted from The Phoenix Partnership (TPP) ResearchOne database(400 GP surgeries in England).3Data were stratified by week ofage over the period 1 September 2015 to 30 November 2015 and1 December 2015 to 29 February 2016. Fever consultation rates(per 100,000 registered practice population in the database) werecompared to the same 3 month periods of the previous 5 years(2010-14) using incident rate ratios (IRR). Pre- and post-vaccinationconsultation rates were applied to the England 0-26 week populationto estimate excess fever consultations.ResultsBetween 1 September and 30 November 2015 the average dailyfever consultation rate for infants aged 0-26 weeks was 4.72/100,000;the incident rate ratio was 1.46 (95% CI, 1.09-1.92). In the 7-10 weekage group the average daily fever consultation rate was 7.79/100,000.The incidence rate was 2.68 times higher than in previous years(95% CI, 1.42-4.94).Between 1 December 2015 and 29 February 2016 the averagedaily consultation rate for infants aged 0-26 weeks was 6.19/100,000.The incidence rate was 1.49 times higher than in the same 3 monthperiod of previous years (95% CI, 1.16-1.90). In infants aged7-10 weeks the average daily consultation rate was 8.44/100,000and the incidence rate was 1.83 times higher than previous years(95% CI 1.03-3.16).Between 1 September 2015 and 29 February 2016 there werean estimated additional 959 fever consultations for infants aged0-26 weeks to English family doctors.ConclusionsWe have demonstrated an innovative use of syndromic surveillanceto quickly and easily assess the impact on healthcare seekingbehaviour for infants with fever following the introduction of a newvaccination into the routine vaccination programme in England. Ourstudy provides reassurance that in infants aged 0-26 weeks therewas no marked increase in consultations following the introductionof the new MenB vaccination. However, in some age groups below0-26 weeks there was an increase in healthcare seeking behaviour forfever, in particular, the 7-10 week age group which includes infantsaged 8 weeks receiving their first vaccination. Other age groups alsodemonstrated increased fever consultations during these two periods,albeit at less significant levels. We will analyse data for the full yearfrom 1 September 2015 to further explore these findings, investigatepotential confounders and assess trends since vaccine introduction.