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.

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.

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.

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.

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.