CASCADIA: a prospective community-based study protocol for assessing SARS-CoV-2 vaccine effectiveness in children and adults using a remote nasal swab collection and web-based survey design.

INTRODUCTION: Although SARS-CoV-2 vaccines were first approved under Emergency Use Authorization by the Food and Drug Administration in late 2020 for adults, authorisation for young children 6 months to <5 years of age did not occur until 2022. These authorisations were based on clinical trials, understanding real-world vaccine effectiveness (VE) in the setting of emerging variants is critical. The primary goal of this study is to evaluate SARS-CoV-2 VE against infection among children aged >6 months and adults aged <50 years. METHODS: CASCADIA is a 4-year community-based prospective study of SARS-CoV-2 VE among 3500 adults and paediatric populations aged 6 months to 49 years in Oregon and Washington, USA. At enrolment and regular intervals, participants complete a sociodemographic questionnaire. Individuals provide a blood sample at enrolment and annually thereafter, with optional blood draws every 6 months and after infection and vaccination. Participants complete weekly self-collection of anterior nasal swabs and symptom questionnaires. Swabs are tested for SARS-CoV-2 and other respiratory pathogens by reverse transcription-PCR, with results of selected pathogens returned to participants; nasal swabs with SARS-CoV-2 detected will undergo whole genome sequencing. Participants who test positive for SARS-CoV-2 undergo serial swab collection every 3 days for 21 days. Serum samples are tested for SARS-CoV-2 antibody by binding and neutralisation assays. ANALYSIS: The primary outcome is SARS-CoV-2 infection. Cox regression models will be used to estimate the incidence rate ratio associated with SARS-CoV-2 vaccination among the paediatric and adult population, controlling for demographic factors and other potential confounders. ETHICS AND DISSEMINATION: All study materials including the protocol, consent forms, data collection instruments, participant communication and recruitment materials, were approved by the Kaiser Permanente Interregional Institutional Review Board, the IRB of record for the study. Results will be disseminated through peer-reviewed publications, presentations, participant newsletters and appropriate general news media.

Differences in influenza vaccination by gender identity and state-level gender equity policies: Behavioral Risk Factor Surveillance System, 2015-2019.

BACKGROUND: It is estimated that there are one million transgender and over 340,000 gender non-conforming people in the United States, many of whom face significant health disparities including access to healthcare. Although previous studies have reported greater vaccine uptake in women compared to men, national-level estimates of influenza vaccine uptake among transgender and non-binary people are unknown. This study aims to characterize differences in influenza vaccine uptake by gender identity and examine associations between vaccination status and state-level gender equity policies. METHODS: We used cross-sectional data from adults participating in the 2015-2019 United States Behavioral Risk Factors Surveillance System surveys. Weighted prevalence differences (PDs) and associated confidence intervals (CIs) of being unvaccinated against influenza by self-reported gender identity were estimated using generalized linear regression models. RESULTS: Compared to cisgender women (unvaccinated prevalence = 57.3%), the prevalence of being unvaccinated was significantly higher among cisgender men (64.4%; PD = 7.0 per 100, 95% CI: 6.7-7.4), transgender women (65.4%; PD = 8.1 per 100, 95% CI 4.0-12.2), transgender men (64.6%; PD = 7.3 per 100, 95% CI: 2.7-11.8), and gender non-conforming individuals (64.6%; PD = 7.2 per 100, 95% CI: 1.3-13.2). This pattern was similar among individuals living in states with protective versus restrictive gender equity policies. CONCLUSIONS: Our results identified a disparity in influenza vaccine uptake among individuals across the gender spectrum. To improve vaccine equity, future research should explore barriers to and facilitators of vaccine uptake by gender identity, which could inform policies and health promotion interventions to improve uptake co-designed and implemented with the transgender and non-binary communities.

Dynamics of breast milk antibody titer in the six months following SARS-CoV-2 infection.

BACKGROUND: While a growing body of literature describes antibody dynamics in serum, little is known about breast milk antibody titers in the months following SARS-CoV-2 infection. OBJECTIVES: We evaluated the dynamics of the humoral immune response to SARS-CoV-2 in two women who were breastfeeding when infected. We assessed paired breast milk and serum samples for six months post-infection for antibodies specific to the SARS-CoV-2 receptor binding domain (RBD) of the spike protein. RESULTS: Starting at 10 days after symptom onset, IgA antibody levels were persistent over a 6-month time period in human milk. For both mothers, no detectable IgA was found in the samples collected pre-symptom onset. RBD-specific IgG and IgM antibodies in tandem serum collected from the two donors demonstrated stable IgG levels over the six-month time period post-symptom onset. CONCLUSIONS: We found that breastfeeding mothers produced a durable IgA response for up to six months following COVID-19 infection, suggesting an important role for breast milk in protection of infants.