Understanding the longer-term health impacts of SARS-CoV-2 infection is essential for informing public health policy. While earlier studies suggested increased diabetes risk after infection, evidence for the Omicron period and the modifying effect of vaccination remains limited and inconsistent. A matched cohort study was conducted using a large-scale linked asset covering over 90% of the Australian population, integrating COVID-19 notifications with demographic information and administrative health records. Individuals aged ≥16 years diagnosed with COVID-19 between 15 December 2021 and 31 December 2022 were matched 1:1 to those without COVID-19 by age, sex, and COVID-19 vaccine recency. Cox-models were used to estimate the association between COVID-19 and initiation of diabetes treatment, adjusting for relevant demographic and health-related factors. Negative control outcomes were assessed. Among 5,736,501 matched pairs followed for a median of 200 days, 45,816 initiated diabetes treatment. Compared to those without COVID-19, individuals with COVID-19 had a 14% higher risk of subsequently initiating diabetes treatment (aHR 1.14 [95%CI 1.12; 1.17]), with the highest risk observed among those hospitalised due to COVID-19 (aHR 2.52 [95%CI 2.23; 2.84]). The risk was also higher for individuals with ≤2 COVID-19 vaccine doses compared to those boosted within the last 90 days (aHR of 1.22 [95%CI 1.18; 1.25] vs 1.08 [95%CI 1.04; 1.12]). We found an increased risk of diabetes following SARS-CoV-2 infection during the Omicron dominant period and a protective effect of COVID-19 vaccination. However, the findings should be interpreted with caution considering the potential for unmeasured confounding.
Jiahui Qian, S. Stepien, Allen Cheng et al.· International Journal of Pop...· 0 citations
OBJECTIVE
This study estimates Australia's measles susceptibility across all age groups. To our knowledge, this study is the first internationally to combine multiple consecutive serosurvey and population immunisation register data.
METHODS
We estimated age-specific measles susceptibility in 2019 using data from nationally representative seroprevalence surveys for people born between 1920 and 1960 (infection-acquired immunity) and those born 1961-1999 (infection/vaccine-acquired immunity). For people born 2000-2018 (vaccine-acquired immunity only), we estimated measles susceptibility from coverage of one or two doses of measles-containing vaccine from the Australian Immunisation Register and presumed vaccine effectiveness, adjusting for 0·04% waning of protection per year.
RESULTS
Susceptibility increased from less than 1% across those born 1920-1960 to 11% for the 1993-1995 cohort, and ranged from 7-14% for those born 2000-2015. We estimated that 1.7 million Australians (6·7%) were susceptible to measles in 2019 (95%UI: 1·3-3·2 million). Among notifications of measles infection between 2008 and 2022, people aged 15-35 years at time of notification accounted for 50%.
CONCLUSIONS
Despite sustained high two-dose measles vaccine coverage, Australia's overall population-level measles immunity is at the lower end of the World Health Organization estimated herd protection threshold range (93-95%).
IMPLICATIONS FOR PUBLIC HEALTH
Our estimates provide baseline data to inform vaccination activities to address immunity gaps in older age groups, particularly those likely to travel internationally.
Zoë Croker, A. McLure, Stephen B Lambert et al.· Australian and New Zealand J...· 1 citation