The short term safety of COVID-19 vaccines in Australia: AusVaxSafety active surveillance, February - August 2021.

OBJECTIVE: To assess the short term safety of the COVID-19 vaccines Comirnaty (Pfizer-BioNTech BNT162b2) and Vaxzevria (AstraZeneca ChAdOx1) in Australia. DESIGN: Prospective observational cohort study; online surveys by AusVaxSafety, a national active vaccine safety surveillance system, three and eight days after vaccination. SETTING, PARTICIPANTS: People aged 16 years or more who received COVID-19 vaccines at sentinel vaccination hubs, general practices, or Aboriginal Community Controlled Health Organisation clinics, 22 February - 30 August 2021. MAIN OUTCOME MEASURES: Primary outcome: proportion of respondents who reported any adverse event following immunisation (AEFI) 0-3 days after vaccination. SECONDARY OUTCOMES: proportions of respondents who reported specific adverse events or medical review for AEFI within seven days of vaccination; impact on usual daily activities; recovery. RESULTS: 4 851 480 people received COVID-19 vaccines at participating sentinel sites during the study period (25% of all COVID-19 vaccine doses administered in Australia to 30 August 2021). 3 035 983 people responded to both surveys (response rate, 62.6%); 35.9% of respondents reported one or more AEFI 0-3 days after Comirnaty dose 1, 54.7% after Comirnaty dose 2, 52.8% after Vaxzevria dose 1, and 22.0% after Vaxzevria dose 2. Local pain, fatigue, headache, and myalgia were the most frequently reported symptoms. After adjusting for demographic characteristics, vaccination site type, jurisdiction, and self-reported medical conditions, the odds of reporting any AEFI were higher for women than men (range of adjusted odd ratios [aORs], by vaccine and dose, 1.53-1.84), for people with a history of anaphylaxis (aOR range, 1.28-1.45), and for people reporting certain underlying conditions, including obesity (aOR range, 1.15-1.75), immunodeficiency (aOR range, 1.04-2.24), or chronic inflammatory disease (aOR range, 1.05-1.75). 0.9% of respondents sought medical advice in the three days following vaccination, most frequently after Comirnaty dose 2 (1.4%) and Vaxzevria dose 1 (1.2%). CONCLUSION: AusVaxSafety active surveillance affirms the short term safety profile of Comirnaty and Vaxzevria vaccines in a large population sample during the first six months of the Australian COVID-19 vaccination program.

The impact of 10 years of human papillomavirus (HPV) vaccination in Australia: what additional disease burden will a nonavalent vaccine prevent?

BACKGROUND: A National human papilloma virus (HPV) Vaccination Programme for the prevention of HPV infection and associated disease using the quadrivalent HPV vaccine (4vHPV) has been funded and implemented in Australia since 2007, initially for girls only and extended to boys in 2013, with uptake rates among the highest observed worldwide. AIM: We report on the impact of this national programme on HPV prevalence and associated disease burden and estimate the potential impact of adopting a nonavalent HPV (9vHPV) vaccine. METHODS: We performed a non-systematic literature review of studies measuring the burden of HPV-associated disease and infection in Australia before and after introduction of HPV vaccination. We also included key national reports with estimates of HPV-related disease burden. RESULTS: Substantial declines in high-grade cervical disease and genital warts among vaccine-eligible women have been observed. Reductions in genital warts incidence and HPV prevalence among heterosexual men of similar age were observed before introduction of the male vaccination programme, indicating a substantial herd effect. 9vHPV vaccine is expected to prevent up to 90% of cervical and 96% of anal cancers. Of an estimated 1,544 HPV-associated cancers in 2012, 1,242 would have been preventable by the 4vHPV vaccine and an additional 187 anogenital cancers by the 9vHPV vaccine. CONCLUSIONS: Vaccination using 4vHPV vaccine has had a large demonstrable impact on HPV-related disease in Australia. A switch to 9vHPV could further reduce the HPV-associated cancer burden. With continued high coverage among both males and females, elimination of vaccine-type HPV disease seems achievable in Australia.

Population-Level Herd Protection of Males From a Female Human Papillomavirus Vaccination Program: Evidence from Australian Serosurveillance.

BACKGROUND: Australia instituted funded female human papillomavirus (HPV) immunization in 2007, followed by a targeted male vaccination program in 2013. To date, Australia is one of only several countries with a funded male HPV immunization program. In 2012-2013, we conducted a survey of HPV seroprevalence in males to assess whether or not a herd impact of female vaccination could be observed. METHODS: We conducted a cross-sectional study of de-identified residual diagnostic test serum samples from males aged 15-39 years from laboratories in 3 Australian states and calculated the proportion seropositive to HPV types 6, 11, 16, and 18. We compared type-specific results by age group against those from a baseline 2005 Australian HPV serosurvey. RESULTS: There were decreases in proportion seropositive for every HPV type across all age groups, many statistically significant. The largest decrease was observed for HPV-11, with decreases of 8- and 9-fold for ages 20-29 and 30-39 years, respectively. Despite substantial reductions in seroprevalence, at least 9% of males were seropositive for at least 1 of the 4 HPV types. CONCLUSIONS: This is the first serosurvey confirming broad population-level impact in males from female HPV vaccination. Our research may assist policy makers considering implementing HPV vaccination programs.

Real-time safety surveillance of seasonal influenza vaccines in children, Australia, 2015.

Increased febrile reactions in Australian children from one influenza vaccine brand in 2010 diminished confidence in influenza immunisation, highlighting the need for improved vaccine safety surveillance. AusVaxSafety, a national vaccine safety surveillance system collected adverse events in young children for 2015 influenza vaccine brands in real time through parent/carer reports via SMS/email. Weekly cumulative data on 3,340 children demonstrated low rates of fever (4.4%) and medical attendance (1.1%). Fever was more frequent with concomitant vaccination.

Australian vaccine preventable disease epidemiological review series: pertussis, 2006-2012.

Despite pertussis vaccine being available since the 1940s and immunisation programs using combined diphtheria-tetanus-pertussis vaccine since the mid-1950s, pertussis has been the most commonly notified vaccine preventable disease in Australia over the past 20 years. Pertussis notification and hospitalisation data have been available nationally since 1993, and provide different perspectives for understanding epidemiological trends. This report follows on from a previous review of Australian pertussis epidemiology from 1995-2005 and summarises routinely collected notification, hospitalisation and mortality data for 2006-2012. During the latter 7-year period, which incorporated epidemics in all jurisdictions, and in which acellular vaccines (as opposed to whole cell vaccines) were used exclusively, the average annual notification rate was more than 2.8 times that of the previous decade. In contrast, hospitalisation and mortality rates remained similar. The pattern of age-specific notification rates changed substantially, with cases aged 15 years or over representing 93% of total cases in 2006, but only 58% by 2012; the steepest increases were seen in children 2-4 and 6-9 years of age. In South Australia, where acellular vaccines were introduced into the primary schedule 2 years earlier than in other jurisdictions except the Northern Territory, a peak in notifications among those aged 5-9 and 10-12 years was observed earlier. Likely contributors to both the overall increase in notifications and changes in age distribution include increased diagnostic testing and more rapid waning of effectiveness following vaccination with acellular compared with whole cell vaccines, exacerbated by cessation of the 18-month dose in the National Immunisation Program from 2003.

An outbreak of staphylococcal food poisoning in a commercially catered buffet.

Staphylococcal food poisoning is a common cause of foodborne illness. In Australia, since 2000, approximately 30% of foodborne Staphylococcus aureus outbreaks reported to OzFoodNet have been associated with foods prepared by commercial caterers. We conducted a retrospective cohort analysis of an outbreak of gastrointestinal illness among participants of an elite sporting event during which 22 individuals became ill after eating a commercially catered buffet dinner in June 2012. All recalled eating fried rice which had been intended for lunch service earlier that day and 20 of the 22 reported eating chicken stir-fry. Though no food samples were available for analysis, laboratory analysis conducted on four faecal specimens resulted in S. aureus being cultured from one specimen and S. aureus enterotoxin detected in another. The known epidemiology of staphylococcal food poisoning suggests a food contaminated by an infected food handler which was subject to temperature abuse may have caused the outbreak. As S. aureus foodborne outbreaks are often underreported, this investigation is a valuable contribution to the evidence-base and understanding of foodborne illness due to S. aureus and staphylococcal enterotoxin.

Background incidence rates of selected adverse events of special interest (AESI) to monitor the safety of COVID-19 vaccines.

BACKGROUND: Determining background rates of medical conditions identified as adverse events of special interest (AESI) that may occur following COVID-19 vaccination is important for contextualising and investigating potential vaccine safety signals. METHODS: We conducted a retrospective population-based cohort study using linked emergency department, hospitalisation and death data for 2017 and 2018 from Australia's most populous state, New South Wales. Incident cases of select neurological conditions, arterial or venous thromboembolic conditions, secondary thrombocytopenia, myocarditis/pericarditis, and unique events of anaphylaxis and generalised convulsions were identified using internationally agreed upon diagnostic (ICD-10) codes. State-specific rates per 100,000 person-years were calculated, with further stratification by age group and sex where clinically relevant to the condition, and the number of expected cases nationally in one and 6 weeks was estimated. RESULTS: Background rates of selected neurological conditions were low with the exception of generalised convulsions for which 1,599-1,872 cases were estimated nationally in a 1-week period in the absence of vaccination. Using a narrow case definition, rates of Guillain-Barré Syndrome (3.9 per 100,000 person-years) were higher than international rates reported elsewhere. Thromboembolic and cerebral venous sinus thrombosis event rates increased with age. Myocarditis occurred more commonly in males, and was highest in males aged 18-24 years, with an estimated 1-4 cases expected nationally in a 1-week period. CONCLUSIONS: Using routinely collected linked healthcare data provides localised estimates of background rates of new onset or periodic AESI which enables rapid estimation of observed-versus-expected rates of events reported following COVID-19 vaccination. This Australian-specific analysis contributes AESI background rates which can be compared with those from other countries to enhance understanding of geographic variability in the frequency of specific AESI in the absence of vaccination, and can be utilised for signal detection during program implementation.

Surveillance of adverse events following immunisation in Australia annual report, 2020.

This report summarises Australian spontaneous surveillance data for adverse events following immunisation (AEFI) for 2020, reported to the Therapeutic Goods Administration (TGA), and describes reporting trends over the 21-year period from 1 January 2000 to 31 December 2020. There were 3,827 AEFI records for vaccines administered in 2020, an annual AEFI reporting rate of 14.9 per 100,000 population. There was a slight (3.8%) decrease in the overall AEFI reporting rate in 2020 compared with 2019 (15.5 per 100,000 population). This decrease in the AEFI reporting rate in 2020 is potentially due to the impact of coronavirus disease 2019 (COVID-19) and was mainly from a decline in reported adverse events related to HPV, dTpa, and seasonal influenza vaccines. AEFI reporting rates for most individual vaccines in 2020 were similar to 2019. The most commonly reported adverse events were injection site reaction (37.1%); pyrexia (18.1%); rash (15.8%); vomiting (7.6%); pain (7.4%); headache (5.7%); and urticaria (5.1%). There were six deaths reported to the TGA. In one of the reports, the timing and clinical findings were consistent with a causal association with vaccination. In the remaining five reports, no clear causal relationship with vaccination was found.

Australian vaccine preventable disease epidemiological review series: Pertussis, 2013-2018.

INTRODUCTION: Significant recent changes in Australian pertussis immunisation policy include the progressive introduction of funded pertussis immunisation programs for pregnant women, from late 2014 to mid-2015 at jurisdictional level and then under the National Immunisation Program from July 2018, and reintroduction of the 18-month booster dose in 2016. This study analyses pertussis notification, hospitalisation, and mortality data from 2013 to 2018 in the context of trends since 1995. METHODS: This study used data from the National Notifiable Diseases Surveillance System, the National Hospital Morbidity Database, and the Australian Coordinating Registry, for descriptive analysis of pertussis notifications, hospitalisations and deaths in Australia by Aboriginal and Torres Strait Islander (Indigenous) status from 2013 to 2018, examining trends between 1995 and 2012 at both the national and jurisdictional level. Incidence rate ratios (IRR) were utilised to compare pertussis incidence in infants aged < 2 months and 6-11 months for each year from the 2015-2018 (post-maternal-vaccination) period against the 2010-2013 (pre-maternal-vaccination) period. RESULTS AND DISCUSSION: Annual national all-age incidence of pertussis notifications between 2013 and 2018 was 63.6 per 100,000 population, 40% less than between 2006 and 2012. Between 2016 and 2018, infants aged < 2 months had the lowest notification rates of age groups < 5 years old, with the highest notification rates in pre-adolescents aged 9-11 years. Compared with the baseline period (2010-2013), the IRR for infants aged < 2 months decreased in each year during the post-maternal-vaccination period from 0.4 (95% confidence interval [95% CI]: 0.3-0.5) in 2015 to 0.1 (95% CI: 0.1-0.2) in 2018. For infants aged 6-11 months, the IRR was 0.9 (95% CI: 0.8-1.0) in 2015, 1.1 (95% CI: 1.0-1.2) in 2016 and declined to 0.7 (95% CI: 0.6-0.8) in 2017 and 2018. Notification and hospitalisation rates in Indigenous children were 3-8 times as high as rates in non-Indigenous children across all age groups < 5 years old. CONCLUSION: Pertussis remains the second most frequently notified vaccine preventable disease in Australia, after influenza, but dramatic decreases in incidence have been observed in infants too young to receive any doses of pertussis-containing vaccine.

Surveillance of adverse events following immunisation in Australia annual report, 2019.

ABSTRACT: This report summarises Australian spontaneous surveillance data for adverse events following immunisation (AEFI) for 2019 reported to the Therapeutic Goods Administration (TGA) and describes reporting trends over the 20-year period from 1 January 2000 to 31 December 2019. There were 3,782 AEFI records for vaccines administered in 2019, an annual AEFI reporting rate of 14.9 per 100,000 population. There was an 11.8% decrease in the overall AEFI reporting rate in 2019 compared to 2018 (16.9 per 100,000 population). This decrease in the AEFI reporting rate in 2019 was mainly attributable to a decline in reported adverse events related to the human papillomavirus (HPV), dTpa, meningococcal ACWY and seasonal influenza vaccines. AEFI reporting rates for most individual vaccines in 2019 were similar to 2018. The most commonly-reported adverse events were injection site reaction (35.8%), rash (16.6%), pyrexia (15.3%), vomiting (8.1%), urticaria (5.8%), pain (5.8%) and headache (5.7%). There were five deaths reported to the TGA. In one report, the timing and clinical findings were consistent with a causal association with vaccination. In the remaining four reports, no clear causal relationship with vaccination was found.

Comparative Postmarket Safety Profile of Adjuvanted and High-Dose Influenza Vaccines in Individuals 65 Years or Older.

Importance: Every year, influenza vaccines are administered to millions of people worldwide to reduce morbidity and mortality from influenza. As new vaccine formulations are increasingly used, monitoring and comparing safety, in addition to vaccine effectiveness, in target populations are essential. Objective: To assess the postmarketing safety profile of 2018 Southern Hemisphere influenza vaccines, particularly 2 new enhanced trivalent inactivated influenza vaccines: an adjuvanted trivalent inactivated influenza vaccine (aIIV3) and high-dose trivalent inactivated influenza vaccine (HD-IIV3), among Australian individuals 65 years or older. Design, Setting, and Participants: This cohort study used solicited short message service-based self-reported survey data on adverse events occurring within 3 to 5 days after receipt of an influenza vaccination. Participants included individuals 65 years or older who received routinely recommended influenza vaccines at 1 of 265 sentinel immunization sites, including primary care, hospital, and community-based clinics, participating in Australia's AusVaxSafety active vaccine safety surveillance system from April 1 to August 31, 2018. Data were analyzed from September 1, 2018, to June 30, 2019. Exposure: Any licensed 2018 influenza vaccine administered in clinical practice. Main Outcomes and Measures: Rates (overall, by brand, and by concomitant vaccine receipt) of adverse events, including medical attendance as a proxy for serious adverse events. Results: Of 72 013 individuals 65 years or older who received an influenza vaccine in 2018, 50 134 individuals (69.6%) responded to the initial survey regarding adverse events experienced after vaccination (median [interquartile range] age, 71 [68-76] years; 27 056 [54.0%] women). Most individuals received an enhanced trivalent inactivated influenza vaccine, including 28 003 individuals (55.9%) who received aIIV3 and 19 306 individuals (38.5%) who received HD-IIV3; 2208 individuals (4.4%) received a quadrivalent inactivated influenza vaccine. Individuals who received HD-IIV3 reported significantly higher rates of any adverse event compared with individuals who received aIIV3 (1716 individuals [8.9%] vs 1796 individuals [6.4%]; P < .001) as well as specific adverse events, including fever (195 individuals [1.1%] vs 164 individuals [0.6%]; P < .001), injection site pain (383 individuals [2.1%] vs 350 individuals [1.3%]; P < .001), and injection site swelling or redness (256 individuals [1.4%] vs 248 individuals [0.9%]; P < .001). Adverse event rates reported by those receiving any quadrivalent inactivated influenza vaccine were similar to rates reported by those receiving aIIV3. Rates of medical care seeking for adverse events associated with aIIV3 and HD-IIV3 were low and comparable (80 individuals [0.3%] vs 56 individuals [0.3%]; P = .91). Conclusions and Relevance: The findings of this large-scale participant-based postmarketing assessment of the safety of 2 new enhanced influenza vaccines used in individuals 65 years or older provide reassuring near-real-time and cumulative data to inform and support confidence in ongoing vaccine use.

Timeliness of signal detection for adverse events following influenza vaccination in young children: a simulation case study.

OBJECTIVES: To determine how soon after commencement of the seasonal influenza vaccination programme, the AusVaxSafety active vaccine safety surveillance system, currently in use across Australia, would have detected a safety signal had it been operating in 2010 when there was an unprecedented number of febrile seizures in young children associated with one specific influenza vaccine brand, Fluvax (CSL Biotherapies). DESIGN: Simulation study. SETTING: Western Australian vaccine influenza coverage and adverse event surveillance data. OUTCOME MEASURES: Simulated solicited responses from caregivers who would have received an SMS survey about adverse events experienced following seasonal influenza vaccination of their children aged 6 months to <5 years. PARTICIPANTS: None. RESULTS: We estimated a >90% probability of a safety signal being detected by AusVaxSafety based on solicited reports for either fever or medical attendance at or before the week ending 28 March 2010, 3 weeks after the start of vaccine distribution. Suspension of the national paediatric influenza vaccination programme as a result of the passive adverse events surveillance operating at the time did not occur until 23 April 2010. CONCLUSIONS: Active vaccine safety surveillance leading to rapid detection of a safety signal would likely have resulted in earlier suspension of Fluvax from the vaccination programme, prevention of many febrile convulsions and maintenance of public confidence in influenza vaccination for young children.

Surveillance of adverse events following immunisation in Australia: annual report, 2018.

This report summarises Australian spontaneous surveillance data for adverse events following immunisation (AEFI) for 2018 reported to the Therapeutic Goods Administration and describes reporting trends over the 19-year period 1 January 2000 to 31 December 2018. There were 4221 AEFI records for vaccines administered in 2018, an annual AEFI reporting rate of 16.9 per 100,000 population. There was a 2.9% increase in the overall AEFI reporting rate in 2018 compared to 2017. This slight increase in reported adverse events in 2018 was likely due to new additions to the National Immunisation Program schedule, namely meningococcal ACWY vaccination for children aged 12 months, enhanced immunogenicity trivalent influenza vaccines for adults aged ≥65 years, and state- and territory-funded seasonal influenza vaccination programs for children aged 6 months to <5 years. AEFI reporting rates for most individual vaccines in 2018 were similar to 2017. The most commonly reported adverse events were injection site reaction (34%), pyrexia (15%), rash (15%), vomiting (8%), headache (6%) and pain (6%). Two deaths were reported to the TGA but no clear causal relationship with vaccination was found.

Transmission of SARS-CoV-2 in Australian educational settings: a prospective cohort study.

BACKGROUND: School closures have occurred globally during the COVID-19 pandemic. However, empiric data on transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) among children and in educational settings are scarce. In Australia, most schools have remained open during the first epidemic wave, albeit with reduced student physical attendance at the epidemic peak. We examined SARS-CoV-2 transmission among children and staff in schools and early childhood education and care (ECEC) settings in the Australian state of New South Wales (NSW). METHODS: Laboratory-confirmed paediatric (aged ≤18 years) and adult COVID-19 cases who attended a school or ECEC setting while considered infectious (defined as 24 h before symptom onset based on national guidelines during the study period) in NSW from Jan 25 to April 10, 2020, were investigated for onward transmission. All identified school and ECEC settings close contacts were required to home quarantine for 14 days, and were monitored and offered SARS-CoV-2 nucleic acid testing if symptomatic. Enhanced investigations in selected educational settings included nucleic acid testing and SARS-CoV-2 antibody testing in symptomatic and asymptomatic contacts. Secondary attack rates were calculated and compared with state-wide COVID-19 rates. FINDINGS: 15 schools and ten ECEC settings had children (n=12) or adults (n=15) attend while infectious, with 1448 contacts monitored. Of these, 633 (43·7%) of 1448 had nucleic acid testing, or antibody testing, or both, with 18 secondary cases identified (attack rate 1·2%). Five secondary cases (three children; two adults) were identified (attack rate 0·5%; 5/914) in three schools. No secondary transmission occurred in nine of ten ECEC settings among 497 contacts. However, one outbreak in an ECEC setting involved transmission to six adults and seven children (attack rate 35·1%; 13/37). Across all settings, five (28·0%) of 18 secondary infections were asymptomatic (three infants [all aged 1 year], one adolescent [age 15 years], and one adult). INTERPRETATION: SARS-CoV-2 transmission rates were low in NSW educational settings during the first COVID-19 epidemic wave, consistent with mild infrequent disease in the 1·8 million child population. With effective case-contact testing and epidemic management strategies and associated small numbers of attendances while infected, children and teachers did not contribute significantly to COVID-19 transmission via attendance in educational settings. These findings could be used to inform modelling and public health policy regarding school closures during the COVID-19 pandemic. FUNDING: NSW Government Department of Health.

Safety of Human Papillomavirus Vaccines: An Updated Review.

Human papillomavirus (HPV) vaccines are now included in immunisation programmes in 71 countries. Unfortunately, uptake has been impacted in some countries by reduced confidence in the safety of the HPV vaccine. In 2013, we published an extensive review demonstrating a reassuring safety profile for bivalent (2vHPV) and quadrivalent (4vHPV) vaccines. A nonavalent (9vHPV) vaccine is now available and HPV immunisation programmes have been extended to males in 11 countries. The aim of this updated narrative review was to examine the evidence on HPV vaccine safety, focusing on the 9vHPV vaccine, special populations and adverse events of special interest (AESI). The previous searches were replicated to identify studies to August 2016, including additional search terms for AESI. We identified 109 studies, including 15 population-based studies in over 2.5 million vaccinated individuals across six countries. All vaccines demonstrated an acceptable safety profile; injection-site reactions were slightly more common for 9vHPV vaccine than for 4vHPV vaccine. There was no consistent evidence of an increased risk of any AESI, including demyelinating syndromes or neurological conditions such as complex regional pain or postural orthostatic tachycardia syndromes. The risk-benefit profile for HPV vaccines remains highly favourable.

Active surveillance of 2017 seasonal influenza vaccine safety: an observational cohort study of individuals aged 6 months and older in Australia.

OBJECTIVE: To actively solicit adverse events experienced in the days following immunisation with quadrivalent inactivated influenza vaccine using Australia's near real-time, participant-based vaccine safety surveillance system, AusVaxSafety. DESIGN AND SETTING: Observational cohort study conducted in 194 sentinel surveillance immunisation sites (primary care, hospital and community-based clinics) across Australia. PARTICIPANTS: Individuals aged ≥6 months who received a routine seasonal influenza vaccine at a participating site (n=102 911) and responded to a survey (via short message service or email) sent 3 days after vaccination about adverse events experienced (n=73 892; 71.8%). MAIN OUTCOME MEASURE: Near real-time and cumulative participant-reported rates of any adverse event, fever or medical attendance experienced within 3 days after vaccination overall, by brand, age, pregnancy status and concomitant vaccine receipt. RESULTS: Participant median age was 57 years (range: 6 months to 102 years); 58.1% (n=42 869) were female and 2.7% (n=2018) were pregnant. Near real-time fast initial response cumulative summation and Bayesian analyses of weekly event rates did not demonstrate a safety signal. Children aged 6 months to 4 years had higher event rates (522/6180; 8.4%) compared with older ages; participants aged ≥65 years reported fewer events (1695/28 154; 6.0%). There were no clinically significant differences in safety between brands, by age group or overall. Cumulative data analysis demonstrated that concomitant vaccination was associated with increased rates of fever (2.1% vs 0.8%) and medical attendance (0.8% vs 0.4%), although all rates were low and did not exceed expected levels. CONCLUSIONS: Novel, postmarketing AusVaxSafety surveillance demonstrated comparable and expected safety outcomes for the 2017 quadrivalent inactivated influenza vaccine brands used in Australia. These near real-time, participant-reported data are expected to encourage confidence in vaccine safety and promote uptake.

Active SMS-based influenza vaccine safety surveillance in Australian children.

INTRODUCTION: Australia's novel, active surveillance system, AusVaxSafety, monitors the post-market safety of vaccines in near real time. We analysed cumulative surveillance data for children aged 6 months to 4 years who received seasonal influenza vaccine in 2015 and/or 2016 to determine: adverse event following immunisation (AEFI) rates by vaccine brand, age and concomitant vaccine administration. METHODS: Parent/carer reports of AEFI occurring within 3 days of their child receiving an influenza vaccine in sentinel immunisation clinics were solicited by Short Message Service (SMS) and/or email-based survey. Retrospective data from 2 years were combined to examine specific AEFI rates, particularly fever and medical attendance as a proxy for serious adverse events (SAE), with and without concomitant vaccine administration. As trivalent influenza vaccines (TIV) were funded in Australia's National Immunisation Program (NIP) in 2015 and quadrivalent (QIV) in 2016, respectively, we compared their safety profiles. RESULTS: 7402 children were included. Data were reported weekly through each vaccination season; no safety signals or excess of adverse events were detected. More children who received a concomitant vaccine had fever (7.5% versus 2.8%; p < .001). Meningococcal B vaccine was associated with the highest increase in AEFI rates among children receiving a specified concomitant vaccine: 30.3% reported an AEFI compared with 7.3% who received an influenza vaccine alone (p < .001). Reported fever was strongly associated with medical attendance (OR: 42.6; 95% Confidence Interval (CI): 25.6-71.0). TIV and QIV safety profiles included low and expected AEFI rates (fever: 4.3% for TIV compared with 3.2% for QIV (p = .015); injection site reaction: 1.9% for TIV compared with 3.0% for QIV (p < .001)). There was no difference in safety profile between brands. DISCUSSION: Active participant-reported data provided timely vaccine brand-specific safety information. Our surveillance system has particular utility in monitoring the safety of influenza vaccines, given that they may vary in composition annually.

The changing epidemiology of measles in an era of elimination: lessons from health-care-setting transmissions of measles during an outbreak in New South Wales, Australia, 2012.

INTRODUCTION: In countries where measles is rare, health-care-setting transmissions remain problematic. Australia experienced its largest measles outbreak in 15 years in 2012 with 199 cases reported nationally; 170 cases occurred in the state of New South Wales (NSW) with symptom onset between 7 April and 29 November 2012. METHODS: A descriptive study was conducted using measles case data obtained from metropolitan Sydney local health districts in NSW in 2012. Characteristics of measles source and secondary cases were described. Details of health-care presentations resulting and not resulting in measles transmission were also analysed. RESULTS: There were 168 confirmed and two probable cases resulting in 405 documented health-care presentations. Thirty-four secondary cases acquired in health-care settings were identified, including 29 cases resulting from 14 source cases and 5 cases whose source could not be identified. Health-care-acquired cases accounted for 20% of all cases in this outbreak. Source cases were more likely to be of Pacific Islander descent (P = 0.009) and to have had more presentations before diagnosis (P = 0.012) compared to other cases. The percentage of presentations to emergency departments was higher for presentations that resulted in transmission compared to those that did not (71.4% and 37.6%, respectively, P = 0.028). There were no significant differences between transmission and non-transmission presentations with respect to presence of rash and infection control measures (P = 0.762 and P = 0.221, respectively), although the power to detect these differences was limited. Rash was reported at 66% of the presentations. CONCLUSION: Development of and adherence to protocols for the management of patients presenting to hospitals with fever and rash will minimize secondary transmission of measles.

An assessment of measles vaccine effectiveness, Australia, 2006-2012.

OBJECTIVE: Vaccine effectiveness analysis serves as a critical evaluation for immunization programmes and vaccination coverage. It also contributes to maintaining public confidence with the vaccine providers. This study estimated measles vaccine effectiveness at the population level using Australian national notifications data between 2006 and 2012. METHODS: Notification data were obtained from the National Notifiable Diseases Surveillance System. Vaccination status was classified according to whether a case had received zero, one or two doses of measles-containing vaccine. Cases aged less than 1 year and those with unknown vaccination status were excluded. All children with disease onset between 1 January 2006 and 31 December 2012 who were born after 1996 were included. Cases were matched to controls extracted from the Australian Childhood Immunization Register according to date of birth and jurisdiction of residence. Vaccine effectiveness was estimated by conditional logistic regression. Sensitivity analyses were conducted to test data robustness. RESULTS: Vaccine effectiveness was estimated at 96.7% (95% confidence interval [CI]: 94.5-98.0%) for one dose and 99.7% (95% CI: 99.2-99.9%) for two doses of measles vaccine. For at least one dose, effectiveness was estimated at 98.7% (95% CI: 97.9-99.2%). Sensitivity analyses did not significantly alter the base estimates. DISCUSSION: Vaccine effectiveness estimates suggested that the measles vaccine was protective at the population level between 2006 and 2012. However, vaccination coverage gaps may have contributed to recent measles outbreaks and may represent a serious barrier for Australia to maintain measles elimination status.