Immunisation coverage, 2012.

This, the 6th annual immunisation coverage report, documents trends during 2012 for a range of standard measures derived from Australian Childhood Immunisation Register (ACIR) data, and National Human Papillomavirus (HPV) Vaccination Program Register data. These include coverage at standard age milestones and for individual vaccines included on the National Immunisation Program (NIP) and coverage in adolescents and adults. The proportion of Australian children 'fully vaccinated' at 12, 24 and 60 months of age was 91.7%, 92.5% and 91.2%, respectively. For vaccines available on the NIP but not assessed during 2012 for 'fully vaccinated' status or for eligibility for incentive payments (rotavirus and pneumococcal at 12 months and meningococcal C and varicella at 24 months) coverage varied. Although pneumococcal vaccine had similar coverage at 12 months to other vaccines, coverage was lower for rotavirus at 12 months (83.6%) and varicella at 24 months (84.4%). Although 'fully vaccinated' coverage at 12 months of age was lower among Indigenous children than non-Indigenous children in all jurisdictions, the extent of the difference varied, reaching a 15 percentage point differential in South Australia but only a 0.4 percentage point differential in the Northern Territory. Overall, Indigenous coverage at 24 months of age exceeded that at 12 months of age nationally and for all jurisdictions, but as receipt of varicella vaccine at 18 months is excluded from calculations, this represents delayed immunisation, with some contribution from immunisation incentives. The 'fully vaccinated' coverage estimates for vaccinations due by 60 months of age for Indigenous children exceeded 90% at 91% in 2012. Unlike in 2011, at 60 months of age, there was no dramatic variation in coverage between Indigenous and non-Indigenous children for individual jurisdictions. As previously documented, vaccines recommended for Indigenous children only, hepatitis A and pneumococcal vaccine, had suboptimal coverage at 60.1% and 73.1%, respectively, although there was a considerable improvement in coverage from 2011, 57.7% and 68.2% respectively. On-time receipt (before 49 months of age) of vaccines by Indigenous children at the 60-month milestone age improved substantially between 2011 (19%) and 2012 (38%) but the disparity in on-time vaccination between Indigenous and non-Indigenous children worsened at the 60-month age milestone from 2011 (from 1.8 to 5.4 percentage points) and remained the same for the 12 and 24-month age milestones. By late 2012, the percentage of children who received the 1st dose of DTPa vaccine dose at less than 8 weeks of age was greater than 50% in all but 1 jurisdiction and greater than 70% for New South Wales, the Australian Capital Territory and Tasmania. Further, by late 2012, the percentage of children who received the 4th dose of DTPa vaccine dose at less than 4 years of age was greater than 30% in 3 jurisdictions. The percentage of children whose parents officially objected to vaccination in Australia was 1.7% and this figure varied by jurisdiction. However, there is a further 2.1% of children whose parents don't officially object but whose children have no vaccines recorded on the ACIR. Coverage data for the 3rd dose of HPV from the national HPV register in the school catch up program was similar to 2011 at 71% but was substantially lower for the catch up program for females outside school (44%-69%), although this was an improvement from 2011.

Surveillance of adverse events following immunisation in Australia, 2012.

This report summarises Australian passive surveillance data for adverse events following immunisation (AEFI) reported to the Therapeutic Goods Administration (TGA) for 2012. It also describes reporting trends over the 13-year period 1 January 2000 to 31 December 2012. There were 1,897 AEFI records for vaccines administered in 2012, a decrease of 22% from 2,417 in 2011. The decrease in 2012 compared with 2011 was mainly attributable to a drop in the reports following receipt of the 23-valent pneumococcal polysaccharide vaccine (405 reduced to 133). However, reporting rates for some other vaccines such as rotavirus and varicella vaccines were higher in 2012 than 2011. Although an increase was observed in estimated reporting rates for rotavirus and varicella in children aged < 7 years in 2012 compared with 2011, it was not statistically significant. There were 370 AEFI records (37.2 per 100,000 doses) for the pneumococcal conjugate vaccine in 2012, which was fewer than in 2011 (43.4 per 100,000 doses). The most commonly reported reactions were injection site reactions (40%), fever (22%), allergic reactions (19%) and rash (10%). Only 7% of all the reported adverse events were categorised as serious. There were 2 reports of death, which were investigated by the TGA and no clear causal relationship with vaccination was found.

Immunisation coverage annual report, 2011.

This, the 5th annual immunisation coverage report, documents trends during 2011 for a range of standard measures derived from Australian Childhood Immunisation Register data, and National Human Papillomavirus (HPV) Vaccination Program Register data. The proportion of children 'fully vaccinated' at 12, 24 and 60 months of age was 91.4%, 92.2% and 89.5% respectively. Although pneumococcal vaccine had similar coverage at 12 months to other vaccines, coverage was lower for rotavirus at 12 months (83.8%) and varicella at 24 months (83.9%). By late 2011, the percentage of children who received the 1st dose of DTPa vaccine dose at less than 8 weeks of age was greater than 50% in 3 jurisdictions, the Australian Capital Territory, Victoria, and Queensland and at 70% for New South Wales and Tasmania. Although coverage at 12 months of age was lower among Indigenous children than non-Indigenous children in all jurisdictions, the extent of the difference varied. Overall, coverage at 24 months of age exceeded that at 12 months of age nationally. At 60 months of age, there was dramatic variation between individual jurisdictions, ranging from coverage 8% lower in Indigenous children in South Australia to 6% higher in the Northern Territory. As previously documented, vaccines recommended for Indigenous children only (hepatitis A and pneumococcal polysaccharide vaccine) had suboptimal coverage at 60% and 68%, respectively. On-time receipt (before 49 months of age) of vaccines by Indigenous children at the 60-month milestone age improved between 2010 (18%) and 2011 (19%) but the disparity in on-time vaccination between Indigenous and non-Indigenous children increased at all 3 age milestones. The percentage of vaccine objectors in 2011 (1.7%) has increased from 2007 when it was 1.1%. Coverage data for the 3rd dose of HPV from the national HPV register in the school catch up program was 71% but was substantially lower for the catch-up program for women outside school (39%-67%), although this was an improvement from 2010.

Annual report: Surveillance of adverse events following immunisation in Australia, 2011.

This report summarises Australian passive surveillance data for adverse events following immunisation (AEFI) reported to the Therapeutic Goods Administration (TGA) for 2011, and describes reporting trends over the 12-year period 2000 to 2011. There were 2,327 AEFI records for vaccines administered in 2011, a decrease of 40% from 3,894 in 2010. The decrease in 2011 was attributable to a decline in reporting following seasonal influenza (2,354 to 483) and pandemic H1N1 (pH1N1) influenza vaccines (514 to 2). However, reporting rates for some other vaccines were higher in 2011 compared with 2010. The 13-valent pneumococcal conjugate vaccine (13vPCV) replaced the 7-valent pneumococcal conjugate vaccine (7vPCV) and was suspected of involvement in 236 AEFI cases (48 per 100,000 doses). An increase in the number of reports following rotavirus (from 40 to 56 per 100,000 doses), and the hexavalent infant vaccine (from 27 to 40 per 100,000 doses), may have been due at least in part to co-administration with 13vPCV. Reports following DTPa-IPV also increased (from 94 to 139 per 100,000 doses), continuing a trend since 2009. AEFI reports following receipt of the 23-valent pneumococcal vaccine also increased markedly in those aged ≥65 years, from 155 to 288 records. In response to the increase in reports following 23vPPV, boosters are no longer recommended for those without medical risk factors. The most commonly reported reactions were injection site reactions, fever, allergic reactions and malaise. Only 7% of all the reported adverse events were categorised as serious, as per the database definitions, although some events classified as non-serious may have caused severe illness. Three deaths were temporally associated with vaccination; however, all were attributed to causes other than vaccination. The increase in 2011 was predominately due to reports of injection site reactions (49% increase in 2011). Increases in some instances may also be partly attributable to an increasing propensity to report AEFI.

Tetanus Immunity and Epidemiology in Australia, 1993-2010.

BACKGROUND: This study evaluates trends in tetanus immunity and epidemiology over the last two decades in Australia, drawing on two national serological surveys and national tetanus morbidity data, to justify current Australian adult tetanus booster recommendations. METHODS: We compare tetanus immunity level between two national serosurveys, and examine incidence trends using the most accurate estimation of the true number of cases by correcting for under-ascertainment. RESULTS: Tetanus immunity in people aged <60 years is high, but the elderly, particularly the female elderly, may not be adequately protected. Over the past twenty years older people have regularly accounted for the highest number of tetanus cases, with an increasing proportion of cases. CONCLUSION: Despite a positive decrease in tetanus incidence, there remains a significant burden in the elderly population of an entirely preventable disease. Supplying a funded booster dose of dTpa at 65 years would be, potentially, an effective strategy to prevent tetanus cases in Australia.

Hepatitis B Seroepidemiology in Australia, One Decade After Universal Vaccination of Infants and Adolescents.

BACKGROUND: This study assessed the impact of the staged introduction of universal infant and adolescent catch-up hepatitis B vaccination programs on the prevalence of immunity and past hepatitis B virus (HBV) infection in targeted cohorts over almost a decade in Australia. METHODS: We compared the prevalence of immunity in relevant cohorts of children and adolescents in repeated national serological surveys conducted in 1998-99, 2002 and 2007. Residual sera (n =2210) collected opportunistically from Australian laboratories in 2007 were tested for antibody to hepatitis B surface antigen (anti-HBs) indicating vaccine-induced immunity; sera from individuals aged 12-29 years with anti-HBs detected (n =386) were then tested for hepatitis B core antibody (anti-HBc) to identify past hepatitis B infection. RESULTS: In 2007, compared with the baseline period of 1998-99, anti-HBs prevalence had increased significantly in all age groups below 24 years, by more than double in target children. Prevalence of anti-HBc was zero in the 12-14 years and reduced by 71% in those aged 15-19 years. The hepatitis B vaccination protected a significant number of targeted adolescents with a modest vaccine uptake (57% to 60% nationally). CONCLUSION: In a setting without incentives or school entry requirements, adolescent vaccination coverage was significantly higher when delivered by school-based rather than GP-based mechanisms. A cohort of children was growing up in Australia with a high prevalence of vaccineinduced immunity against hepatitis B, providing the best opportunity for controlling HBV infection in Australia.

Diphtheria Immunity in Australia: Should we be Concerned?

OBJECTIVES: We report the results of the 2007 national serological survey of immunity to diphtheria in Australia to assess the impact of recent schedule changes on diphtheria immunity, and the adequacy of current policy in the context of increased international travel of people and pathogens. METHODS: Residual sera (n =1656) collected opportunistically from Australian laboratories in 2007 were tested for diphtheria antibody levels using an enzyme immunoassay, with the protective threshold defined as ≥0.1 IU/mL. About 40% of adults aged ≥30 years are susceptible to diphtheria; following the removal of the 18-month booster and its replacement with a dose in adolescence offered through school-based dTpa vaccination program, 59% of children aged 3 years were susceptible to diphtheria, whilst adolescents demonstrated improved immunity. RESULTS: There is no apparent boosting of diphtheria immunity from meningococcal group C conjugate (MCC) or seven-valent pneumococcal conjugate (7vPCV) vaccines in relevant age groups. CONCLUSION: Australians who travel to diphtheria-endemic areas should be up-to-date with their vaccinations. Close monitoring of population immunity levels against diphtheria remains important to ensure that immunity does not decline to a level where wide-spread transmission would be possible.

Annual report: surveillance of adverse events following immunisation in Australia, 2010.

This report summarises Australian passive surveillance data for adverse events following immunisation (AEFI) reported to the Therapeutic Goods Administration (TGA) for 2010, and describes reporting trends over the 11-year period 2000 to 2010. There were 3,894 AEFI records for vaccines administered in 2010, the highest number reported in any year, and a 63% increase over the 2,396 in 2009. The increase was almost entirely attributable to the large number of reports following seasonal influenza (n = 2,354) and pandemic H1N1 (pH1N1) influenza vaccines (n = 514). In children < 7 years of age, the number of reports following influenza vaccine increased almost 100-fold from 17 in 2009 to 1,693 in 2010 and, for people aged > or =18 years, from 135 to 496. For seasonal influenza vaccine, a disproportionate number of reports were from Western Australia (34%), consistent with more widespread influenza vaccination of children in that state, and 79% were identified as being associated with Fluvax or Fluvax junior (CSL Biotherapies). For pH1N1 vaccine, the number of reports in children < 7 years of age increased from 23 in 2009 to 329 in 2010, but was available for this age group for only 1 month (December) in 2009. In those aged > or = 18 years, for whom the pH1N1 vaccine was available from late September 2009, pH1N1 vaccine reports decreased from 1,209 in 2009 to 109 in 2010. For influenza vaccines, 79% of reports included fever, 45% allergic reactions and 15% malaise. In children aged < 7 years, there were 169 reports of convulsions (127 febrile), compared with 19 in 2009. In contrast, for non-influenza vaccines, reporting rates in children < 7 years of age increased only marginally from 14.1 per 100,000 in 2009 to 19.3 per 100,000 in 2010. Four deaths temporally associated with immunisation were reported but none were considered to have a causal association.

Annual report: surveillance of adverse events following immunisation in Australia, 2009.

This report summarises Australian passive surveillance data for adverse events following immunisation (AEFI) reported to the Therapeutic Goods Administration (TGA) for 2009, and describes reporting trends over the 10-year period 2000 to 2009. There were 2,396 AEFI records for vaccines administered in 2009, the highest number reported, a 46% increase over the 1,638 in 2008. The increase was almost entirely due to reports related to the introduction of pandemic H1N1 (pH1N1) 2009 influenza vaccine from September 2009 (n = 1,312) largely from the members of the public. The pH1N1 AEFI reporting rate for people aged > or = 18 years was 34.2 per 100,000 administered doses compared with 2.8 for seasonal influenza vaccine. The rates in > or = 65 year-olds were 28.0, 1.6 and 13.3 for pH1N1, seasonal influenza and polysaccharide pneumococcal, respectively. The high reporting rate for pH1N1 vaccine is likely to be at least partly due to enhanced reporting seen for all new vaccines and greater levels of reporting from members of the public in response to the implementation of strategies to encourage reporting, as part of the pH1N1 program. For children < 7 years, AEFI reporting rates in 2009 (14.1 per 100,000 administered doses) were similar to previous years. There were 193 (8%) AEFI reports classified as serious; 6 deaths temporally associated with immunisation were reported but none were judged to have a causal association. As in previous years, the most commonly reported reactions were allergic reaction, injection site reaction, fever, headache, malaise, nausea and myalgia. The most commonly reported reactions following pH1N1 influenza vaccine were allergic reaction (n = 381), headache (n = 289), fever (n = 235), pain (n = 186), nausea (n = 180) and injection site reaction (n = 178). The data within the limitation of passive surveillance provide a reference point for ongoing reporting of trends in AEFI by age group, severity and vaccine type and illustrate the value of the national TGA database as a surveillance tool for monitoring AEFI nationally.

Immunisation coverage annual report, 2008.

This, the 2nd annual immunisation coverage report, documents trends during 2008 for a range of standard measures derived from Australian Childhood Immunisation Register data, including overall coverage at standard age milestones and for individual vaccines included on the National Immunisation Program (NIP). Coverage by indigenous status and mapping by smaller geographic areas as well as trends in timeliness are also summarised according to standard templates. With respect to overall coverage, Immunise Australia Program targets have been reached for children at 12 and 24 months of age but not for children at 5 years of age. Coverage at 24 months of age exceeds that at 12 months of age, but as receipt of varicella vaccine at 18 months is excluded from calculations of 'fully immunised' this probably represents delayed immunisation, with some contribution from immunisation incentives. Similarly, the decrease in coverage estimates for immunisations due at 4 years of age from March 2008, is primarily due to changing the assessment age from 6 years to 5 years of age from December 2007. A number of individual vaccines on the NIP are not currently assessed for 'fully immunised' status or for eligibility for incentive payments. These include pneumococcal conjugate and meningococcal C conjugate vaccines for which coverage is comparable to vaccines which are assessed for 'fully immunised' status, and rotavirus and varicella vaccines for which coverage is lower. Coverage is also suboptimal for vaccines recommended for Indigenous children only (i.e. hepatitis A and pneumococcal polysaccharide vaccine) as previously reported for other vaccines for both children and adults. Delayed receipt of vaccines is an important issue for vaccines recommended for Indigenous children and has not improved among non-Indigenous children despite improvements in coverage at the 24-month milestone. Although Indigenous children in Australia have coverage levels that are similar to non-indigenous children at 24 months of age, the disparity in delayed vaccination between Indigenous and non-indigenous children, which is up to 18% for the 3rd dose of DTP, remains a challenge.