Stakeholder perspectives of immunisation delivery for adolescents with disability in specialist schools in Victoria, Australia: 'we need a vaccination pathway'.

BACKGROUND: Adolescents with disability have lower vaccination rates than the general population, including HPV vaccination. Understanding the multi-level influences on vaccination in specialist schools is crucial to achieve optimal vaccination coverage and vaccination experiences for adolescents living with disability. OBJECTIVE: To identify and improve understanding of the facilitators and barriers of HPV vaccination among adolescents with intellectual disabilities or autism in Victorian specialist schools to inform strategies to increase vaccination acceptance and uptake. METHODS: Qualitative interviews with key stakeholders (adolescents with disabilities, parents, school and council immunisation staff) from six specialist schools in Victoria, Australia. Data were analysed thematically. Inductively derived themes were then deductively mapped across the UNICEF 'Journey to Immunization' model. RESULTS: 32 interviews were conducted with stakeholders (2 adolescents, 7 parents, 13 school staff, 10 council staff). Trust in vaccines was high, but knowledge of the HPV vaccine was limited. Barriers included lack of accessible information for parents, the consent process, behavioural challenges and vaccine-related anxiety among students. The immunisation program in special schools was perceived as convenient, however preparing students for vaccination day and catering to individual student needs were key. Participants expressed a need for more parent information about options and additional support for vaccination outside of the school program. CONCLUSIONS: Our study identified a range of facilitators and barriers to the school immunisation program for students with disabilities in specialist schools. The next phase of this work will use co-design workshops to build on the suggestions for improvement and opportunities that could be leveraged to improve vaccination uptake.

Acceptability of an asymptomatic COVID-19 screening program for schools in Victoria, Australia: a qualitative study with caregivers from priority populations.

BACKGROUND: An asymptomatic COVID-19 rapid antigen testing (RAT) screening program was implemented in Victorian schools in January 2022, to support keeping schools open throughout the pandemic. This study explored compliance with the program among caregivers from priority populations in Victorian mainstream and specialist schools. METHODS: We conducted semi-structured interviews between 7-31 March 2022 with caregivers of school-aged children participating in the RAT program in Victoria. Participants were asked about awareness, acceptability, compliance, frequency, and barriers to testing. Recordings were transcribed and deductively analysed using a framework approach. RESULTS: Fifty caregivers participated. They expressed confusion about the 'recommended' program, assuming it was mandatory. Caregivers wanted notification from schools of positive cases to increase motivation for compliance. Culturally and linguistically diverse (CALD) families were compliant; however, in-language resources were limited. Aboriginal or Torres Strait Islander (Koori) families tested less regularly and received information from their community rather than school. Caregivers of children living with disabilities reported behavioural challenges to testing, resulting in distress or non-compliance, and received non-specific information for their children. CONCLUSIONS: To increase engagement with future surveillance programs, caregivers need clarity about optionality, conducting tests, reporting results, and timely notification of cases. Requirements unique to each priority population include: accurate in-language information for CALD caregivers, community-led communication for Koori caregivers, tailored information, less testing, and flexibility for caregivers of children living with a disability. Keeping schools open and having tailored strategies to ensure equitable access for priority populations are essential for future pandemic management.

Immunogenicity, safety, and reactogenicity of a half- versus full-dose BNT162b2 (Pfizer-BioNTech) booster following a two-dose ChAdOx1 nCoV-19, BBIBP-CorV, or Gam-COVID-Vac priming schedule in Mongolia: a randomised, controlled, non-inferiority trial.

Background: COVID-19 vaccine booster doses restore vaccine effectiveness lost from waning immunity and emerging variants. Fractional dosing may improve COVID-19 booster acceptability and uptake and will reduce the per-dose cost of COVID-19 booster programmes. We sought to quantify the immunogenicity, reactogenicity, and safety of a half-dose BNT162b2 (Pfizer-BioNTech) booster relative to the standard formulation. Methods: This randomised, controlled, non-inferiority trial recruited adults in Mongolia primed with a two-dose homologous ChAdOx1 nCov-19 (Oxford-AstraZeneca, n = 129 participants), BBIBP-CorV (Sinopharm (Beijing), n = 399), or Gam-COVID-Vac (Gamaleya, n = 70) schedule. Participants were randomised (1:1) to receive a 15 µg (half-dose) or 30 µg (full-dose) BNT162b2 booster. Participants and study staff assessing reactogenicity were blinded up to day 28. Co-primary endpoints were Wuhan-Hu-1 anti-spike S1 IgG seroresponse 28 days post-boosting and reactogenicity within 7 days of boosting. The non-inferiority margin for the absolute difference in seroresponse was -10%. Differences in seroresponse were estimated from logistic regression with marginal standardisation. Geometric mean ratios of IgG were also estimated. ClinicalTrials.gov Identifier: NCT05265065. Findings: Between May 27th and September 30th, 2022, 601 participants were randomized to full-dose BNT162b2 (n = 300) or half-dose (n = 301). 598 were included in safety analyses, and 587 in immunological analyses. The frequency of grade 3-4 reactions was similar between arms (half-dose: 4/299 [1.3%]; full-dose: 6/299 [2.0%]). Across all severity grades, half-dose recipients reported fewer local and systemic reactions (60% versus 72% and 25% versus 32%, respectively). Seroresponse was 84.7% (250/295) and 86.6% (253/292) in the half-dose and full-dose arms, respectively (Difference: -2.8%; 95% CI -7.7, 2.1). Geometric mean IgG titres were similar in those receiving full and half-dose boosters for the ChAdOx1 and BBIBP-CorV primed groups, but lower in the half-dose arm in Gam-COVID-Vac-primed participants (GMR: 0.71; 95% CI 0.54, 0.93). Interpretation: Half-dose BNT162b2 boosting elicited an immune response that was non-inferior to a full-dose, with fewer reactions, in adults primed with ChAdOx1 nCov-19 or BBIBP-CorV. Half-dose boosting may not be suitable in adults primed with Gam-COVID-Vac. Half-dose BNT162b2 boosting may be considered in populations primed with ChAdOx1 nCov-19 or BBIBP-CorV. Funding: Coalition for Epidemic Preparedness Innovations (CEPI).