Abstract RATIONALE: Chronic lower respiratory diseases (CLRD) confer higher risks from respiratory viral infections, hence CLRD patients are prioritized for influenza, pneumococcal, and COVID-19 vaccination. Nonetheless, vaccine deferral and declination remain common. Given that COVID-19 vaccination is particularly polarizing, and attitudes toward it may differ from other vaccines, we assessed COVID-19 vaccination behaviors and attitudes in adults with versus without CLRD and/or smoking history, which is strongly associated with CLRD risk. METHODS: We pooled data from 10 cohorts participating in the Collaborative Cohort of Cohorts for COVID-19 Research (C4R) that collected pre-pandemic data on self-reported physician diagnosis of asthma or COPD. C4R assessed COVID-19 vaccination status through three waves of standardized questionnaires (2020-2022, 2021-2023, 2023-2024). Prompt COVID-19 vaccination was defined as self-report of receiving at least one COVID-19 vaccine by May 1, 2021. Cumulative COVID-19 vaccine count was self-reported on the Wave 3 Questionnaire. Vaccine attitudes and receipt of influenza and/or pneumococcal vaccines were self-reported on the Wave 1 or 2 Questionnaire. Age-adjusted Poisson regression was used to test associations of vaccination behaviors with CLRD and smoking status at the most recent pre-pandemic exam. RESULTS: Of 20,034 participants (pre-pandemic COPD, 9.3%; asthma, 11.7%; current smoking, 13.4%; former smoking, 36.3%), 64.2% reported prompt COVID-19 vaccination. Among the subset of 10,626 participants completing the Wave 3 Questionnaire in 2023-24, the median COVID-19 vaccine count was 3 (Q1:2, Q3:4). Compared to participants without CLRD, prompt vaccination was more likely in those with asthma (RR=1.04, 95%CI:1.01-1.07, p=0.008) and less likely with COPD (RR=0.94, 95%CI:0.91-0.98, p=0.001), but there were no differences in doses for asthma and COPD. Compared to never smokers, former smoking participants were more likely to receive prompt vaccination (RR=1.11, 95%CI:1.08-1.13, p<0.0001) and more vaccine doses (RR=1.03, 95%CI:1.01-1.05, p=0.015); conversely, current smoking was inversely associated with prompt vaccination (RR=0.94, 95%CI:0.91-0.97, p=0.001) and was associated with fewer doses (RR=0.93, 95%CI:0.89-0.96, p<0.0001). Participants with CLRD versus without CLRD were more likely to report receiving influenza and pneumococcal vaccines, but they were more likely to believe that vaccines are unsafe or ineffective (figure). CONCLUSIONS: COPD was associated with lower likelihood of prompt COVID-19 vaccination. Current smoking was associated with both lower likelihood of prompt COVID-19 vaccination and a lower number of COVID-19 vaccine doses by 2023-24. These associations may be partly attributed to negative vaccine attitudes and beliefs. How the COVID-19 pandemic may have influenced vaccine behaviors and attitudes merits additional study.
Socio-demographic and Clinical Factors Associated With COVID-19 Vaccine Uptake Among Multiethnic US Adults: The C4R Study
Abstract RATIONALE: Deferral and declination of the COVID-19 vaccine is correlated with many factors, including different health guidelines and difficulties accessing the vaccine. In the US, COVID-19 vaccines were made available in tranches of clinical risk starting in December 2020 and were available to all adults on April 19, 2021. In the post-pandemic period, repeating COVID-19 vaccination with updated formulations is broadly recommended. Given that the public health impact of vaccine allocation strategies depends on public acceptance of vaccination, we aimed to evaluate demographic, clinical and social correlates of (1) receiving at least one COVID-19 vaccine by May 1, 2021 (prompt vaccination) and (2) the total number of vaccine doses received (vaccine count) through 2023-2024. METHODS: The Collaborative Cohort of Cohorts for COVID-19 Research (C4R) is a prospective observational meta-cohort study comprising 14 extant NIH-funded population-based cohorts. C4R assessed COVID-19 vaccination using three waves of standardized questionnaires (2020-2021, 2021-2023, 2023-2024). Prompt vaccination was defined by participant self-report of vaccination before May 1, 2021; participants vaccinated after May1, 2021 were classified as non-prompt; participants with missing vaccination information were excluded. Vaccine count was defined by self-report on the 2023-2024 wave Questionnaire. Demographic, clinical and social factors were classified by self-report and/or objective measures from the most recent pre-pandemic cohort exam. Poisson models regressed either prompt vaccination or vaccine count on pre-pandemic factors. RESULTS: Of 17,866 participants (mean age, 6713 years; 60.1% female; 42.1% non-Hispanic White, 22.0% Black, 28.9% Hispanic/Latino, 3.4% American Indian, 2.3% South Asian, 1.4% East Asian), 11,481 (64.3%) reported prompt vaccination. Of the subset of 14,529 participants completing the Wave 3 questionnaire, the median vaccine count in 2023-24 was 3 (Q1, 2; Q3 4). Likelihood of prompt vaccination was higher with greater age, income, and education and with history of diabetes and hypertension; prompt vaccination was less likely with male sex, current smoking, and non-White race and ethnicity (table). Similar associations were observed with respect to vaccine count (table). CONCLUSIONS: In a diverse C4R cohort community-based sample, earlier and greater COVID-19 vaccination was associated with older age and several clinical comorbidities; in contrast, later and lesser vaccine uptake was observed among historically marginalized groups. Whether disparities in COVID-19 vaccination could contribute to disparities in post-COVID-19 conditions merits further investigation.
Associations of SARS-COV-2 Infection and Long COVID With Respiratory Health in the Collaborative Cohort of Cohorts for COVID-19 Research (C4R) Study
Abstract Rationale: SARS-CoV-2 infection may be associated with new or worsening respiratory symptoms that, if persistent, may contribute to “Long COVID.” Research is needed on the prevalence and risk determinants of Long COVID and related respiratory symptoms in adults with and without pre-existing obstructive lung disease or smoking history. Methods: C4R is a prospective, observational study that collected information on SARS-CoV-2 infection using standardized methods across 14 NIH-funded cohorts. The third wave of C4R questionnaires, administered June 2023 to January 2025, assessed self-reported Long COVID via the question, “Do you think that you are experiencing, or have ever experienced, what has been called “long COVID,” or symptoms related to COVID at least a month after your infection?” Questionnaires also assessed the presence (vs absence) of 22 symptoms that have been linked to Long COVID, including cough, shortness of breath, and post-exertional malaise. Pre-pandemic obstructive lung disease (COPD or asthma) and smoking status (ever/never) were harmonized from self-reported data collected at the most recent pre-pandemic cohort exam. Poisson regression was used to assess prevalence ratios (PRs) adjusting for age, sex, BMI, education, and pre-pandemic hypertension, diabetes, cardiovascular disease, and depressive symptoms. PRs for respiratory symptoms were tested according to self-reported Long COVID and history of non-hospitalized or hospitalized infection; effect modification by pre-pandemic lung disease and smoking was assessed by multiplicative interaction terms and in fully stratified models. Results: Among 23,434 questionnaire respondents, 1,484 (6.3%) self-reported Long COVID, including 246/1,262 (19.5%) with pre-pandemic lung disease and 664/4,018 (16.5%) with smoking history. The adjusted PR for Long COVID was 1.17 (95%CI:0.99-1.39;P=0.06) comparing participants with/without lung disease and 1.17 (95%CI:1.04-1.32;P=0.01) comparing participants with/without smoking history. Respiratory symptoms were more prevalent in those with self-reported Long COVID, as well as in those with a history of hospitalized or non-hospitalized infection (Table). Associations were generally stronger in participants without pre-pandemic lung disease (p-interaction<0.05 for all comparisons). Respiratory symptoms were also more prevalent with a history of repeated, and pre-Omicron infections, and were less prevalent among participants vaccinated prior to their first infection; findings were similar even after excluding participants with self-reported Long COVID. Conclusions: Long COVID is common, particularly in adults with pre-existing COPD or asthma or smoking history. Long COVID and history of SARS-CoV-2 infection, including non-hospitalized infections, was associated with greater respiratory symptom burden. Whether SARS-CoV-2 infection or Long COVID are associated with development or progression of obstructive lung diseases warrants future studies.