CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

396

Uptake of 3+ COVID-19 Vaccine Doses Among People Living With HIV in Ontario, Canada Cassandra Freitas 1 , Catharine Chambers 1 , Curtis L. Cooper 2 , Abigail E. Kroch 1 , Sarah A. Buchan 1 , Claire E. Kendall 3 , Jeffrey C. Kwong 1 , Lawrence Mbuagbaw 4 , Nasheed Moqueet 5 , Ann N. Burchell 1 , for the CHESS Study Team 1 University of Toronto, Toronto, Canada, 2 Ottawa Hospital Research Institute, Ottawa, Canada, 3 University of Ottawa, Ottawa, Canada, 4 McMaster University, Hamilton, Canada, 5 Public Health Agency of Canada, Ottawa, Canada Background: In Canada, important socio-demographic differences exist between males and females living with HIV which may impact uptake of COVID-19 vaccines. While most people living with HIV are recommended a 2-dose primary series, a 3-dose primary series is recommended for moderately/ severely immunocompromised individuals including people living with HIV with AIDS-defining illness, recent TB diagnosis, CD4 count <200 cells/uL, or not virally suppressed. Using a population-based approach, we examined uptake of 3+ COVID-19 vaccine doses among people living with HIV in Ontario, Canada. Methods: Community-dwelling adults living with HIV aged ≥19 years were identified using a validated algorithm based on physician billing claims for HIV diagnoses in the past 3 years. Data on COVID-19 vaccine doses and administration dates were ascertained from the Ontario COVID-19 vaccine registry (COVaxON) from December 14, 2020, to August 31, 2022. We used modified Poisson regression with robust standard errors to calculate predictors of 3+ COVID-19 vaccine dose uptake, and report these as adjusted risk ratios and 95% confidence intervals and stratified by sex. Results: Among 20,825 people living with HIV, most received at least one (87.2%) or two (85.3%) COVID-19 vaccine doses as of August 31, 2022, with 64.5% receiving a third dose and 24.4% receiving a fourth dose. While uptake of the first 2 doses was similar among males (85.9%) compared with females (83.0%), there were disparities in 3+ dose uptake by sex (3rd dose: 68.3% vs 50.8%; 4th dose: 27.6% vs 12.5%). Among both males and females, predictors of 3+ dose uptake included older age, being born in Canada, and receiving ≥1 influenza vaccine within the past 2 seasons (see Table). Living in an urban region and having at least 1 comorbidity were predictors among males, while having ≥1 COVID-19 test episode in the 3 months prior to December 14, 2020, was a predictor among females. Positivity for SARS-CoV-2 prior to Dec. 14, 2020, was not associated with 3+ dose uptake. Conclusion: Nearly two thirds of people living with HIV received at least 3 doses of a COVID-19 vaccine, compared with approximately half of the general Ontario population. Yet disparities in uptake remain, especially by sex; this needs further exploration due to differences in social determinants of health between males and females living with HIV. Continued monitoring of COVID-19 vaccine uptake for people living with HIV is critical to inform prevention efforts.

Omicron variant circulating in South Carolina. Vaccinated people with HIV (PWH) was matched with the vaccinated people without HIV (PWoH) via propensity score matching (PSM) with 1:2 rate. A vaccine breakthrough infection was defined as SARS-CoV-2 infection ≥14 days after fully vaccination. We used Cox proportional hazard model to investigate the association between HIV infection and breakthrough infections, adjusting for relevant covariates. Results: Among 2,144,415 vaccinated individuals, 8,335 were PWH and 2,136,080 were PWoH. Over the 18- month observation period, the percentage of breakthrough infections among PWH and PWoH was 5.22% and 4.61% (p=0.0084), respectively. After PSM matching, HIV infection was not significantly associated with breakthrough infection rate. However, when comparing breakthrough infections among individuals without any booster dose, PWH had a higher risk of breakthrough infections (adjusted Hazard Ration [aHR]: 1.19; 95%CI: 1.03, 1.39). Individuals who resided in a county with higher COVID-19 incidence (aHR: 1.05; 95%CI: 1.02, 1.07), being vaccinated during the Omicron dominant period vs Alpha dominant period (aHR: 7.02; 95%CI: 3.12, 15.80), being Black (aHR: 1.20; 95%CI: 1.04, 1.39), or who had chronic pulmonary disease (aHR: 1.36; 95%CI: 1.10, 1.68) were associated with higher odds of breakthrough infections, while prior COVID-19 infection (aHR: 0.37; 95%CI: 0.28, 0.48) and being vaccinated with Moderna vs Pfizer (aHR: 0.77; 95%CI: 0.66, 0.90) was negatively associated with the outcome. Comparing with PWoH, PWH with high levels of CD4 count or viral suppression were not associated with breakthrough infections. Conclusion: We did not find an increased risk of breakthrough infections of PWH compared with PWoH. Receipt of a booster dose conferred further Effectiveness and Safety of SARS-CoV-2 mRNA Vaccines in Children: A Population-Based Study in Madrid Miguel Hernán 1 , Alejandro Alvaro-Meca 2 , María J. Calvo-Alcántara 3 , María Luisa Navarro 4 , José T. Ramos 5 , José C. Estévez 3 , Miguel Basanta 3 , Sergio Ruiz 3 , Ángel L. Mataix 3 , Lourdes Cosano 4 , Aura P. Silva 4 , Pilar Salas 4 , Jose R. Arribas 6 , José M. Molero 3 , Juan Berenguer 4 1 Harvard TH Chan School of Public Health, Boston, MA, USA, 2 Universidad Rey Juan Carlos, Madrid, Spain, 3 Servicio Madrileño de Salud, Madrid, Spain, 4 Hospital General Universitario Gregorio Marañón, Madrid, Spain, 5 Hospital Universitario 12 de Octubre, Madrid, Spain, 6 La Paz University Hospital, Madrid, Spain Background: Decisions about COVID-19 vaccination in children require an assessment of benefits such as prevention of COVID-19 hospitalization and multisystem inflammatory syndrome in children (MIS-C), as well as of risks such as myocarditis. In the absence of large, randomized trials, this evidence needs to be obtained from prospective observational studies conducted in large populations over more than 6 months. Methods: We emulated target trials of COVID-19 vaccination among children using the population-wide databases of the Madrid Health Service, which include demographic information, primary care records, hospital data, and pharmacy data. Eligible children were residents of the Madrid region who were aged 6-11 years after 7 December 2021 and 12-17 years after 31 May 2021 (when vaccination was first recommended in each age group), had not been previously vaccinated, and had no prior evidence of SARS-CoV-2 infection. We emulated sequential trials by identifying eligible children who received the first dose of an mRNA vaccine each day between the start of eligibility and December 2022 and matching them (on sex, age, and postcode) with five controls who had remained unvaccinated through that day. After censoring matched sets at vaccination of an unvaccinated child, we estimated the 240-day cumulative incidence (risk) of COVID-19 hospitalization, MIS-C, and myocarditis. We used percentile-based bootstrapping to obtain 95% confidence intervals. Results: The age group 6-11 years included 183,430 vaccinated children and 917,150 controls. Over 240 days, the estimated effectiveness (95% CI) of

Poster Abstracts

398

397

COVID-19 Breakthrough Infections Among People With and Without HIV: A Statewide Cohort Analysis Xueying Yang 1 , Jiajia Zhang 1 , Ziang Liu 1 , Shujie Chen 1 , Bankole Olatosi 1 , Gregory A. Poland 2 , Sharon Weissman 1 , Xiaoming Li 1 1 University of South Carolina at Columbia, Columbia, SC, USA, 2 Mayo Clinic, Rochester, MN, USA Background: Evidence is limited regarding the COVID-19 vaccine effectiveness among people with HIV. This study aims to characterize and compare the COVID-19 breakthrough infections between people with and without HIV across different phases of the pandemic. Methods: Using a statewide HIV cohort data, the study population was adult residents (>18 years old) who were fully vaccinated (i.e., receipt of the second vaccine dose of Pfizer-BioNTech or Moderna or the single-dose of the Janssen vaccine) between January 2, 2021 to April 14, 2022 when Alpha, Delta, or

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CROI 2024