Human papillomavirus vaccine in boys: background rates of potential adverse events

Med J Aust. 2013 Jun 3;198(10):554-8. doi: 10.5694/mja12.11751.


Objectives: To determine background rates of potential adverse events following immunisation (AEFI) before expansion of the quadrivalent human papillomavirus (4vHPV) vaccination program to adolescent boys.

Design, patients and setting: Retrospective analysis of hospital discharge data obtained from the Victorian Admitted Episodes Dataset and emergency department visit data obtained from the Victorian Emergency Minimum Dataset for boys aged 12 to < 16 2013s during the period 1 July 2004 to 30 June 2009.

Main outcome measures: Numbers of and incidence rates for Guillain-Barré syndrome, anaphylaxis, seizures, syncope and other potential AEFI from 1 July 2004 to 30 June 2009, and estimated numbers of events after 4vHPV vaccination assuming no association (other than temporal) with the vaccine.

Results: We estimated background rates of neurological and allergic events in adolescent boys to be 252.9 and 175.2 per 100 000 person-2013s, respectively. Assuming an 80% vaccination rate with three doses per person - which equates to 1 440 000 doses administered nationally per 2013 in the first 2 2013s of the program - about 2.4 episodes of Guillain-Barré syndrome would be expected to occur in the 6 weeks following vaccination. Within 1 day of vaccination, about 3.9 seizures, 0.3 episodes of anaphylaxis and 6.5 acute allergy presentations would be expected.

Conclusions: Routinely collected health outcome administration data can inform postlicensure safety surveillance of target conditions that might be perceived as AEFI.

Publication types

  • Evaluation Study

MeSH terms

  • Adolescent
  • Child
  • Humans
  • Hypersensitivity / epidemiology
  • Hypersensitivity / etiology*
  • Incidence
  • Male
  • Nervous System Diseases / epidemiology
  • Nervous System Diseases / etiology*
  • Papillomavirus Vaccines / adverse effects*
  • Retrospective Studies
  • Victoria / epidemiology


  • Papillomavirus Vaccines