ABSTRACT
INTRODUCTION: Due to increased exposure risk and the potential impact of COVID-19 infection, health care professionals (HCP) are a target group for COVID-19 vaccination. This study aimed to examine the acceptability of COVID-19 vaccines among HCP at the Queen Elizabeth Hospital, Barbados. DESIGN AND METHODS: A cross-sectional survey of HCP was conducted between February 14 and 27, 2021 using an online questionnaire. The questionnaire included demographic information, knowledge of novel coronavirus, intention to accept the COVID-19 vaccination, vaccine literacy (VL), and perceptions and attitudes regarding COVID-19 vaccines. Mean VL scores were calculated. The relationship between socio-demographic variables and vaccine intent was assessed using a multivariable logistic regression model. RESULTS: Of 343 HCPs, 55.1% indicated they would accept the COVID-19 vaccine if it were available; 44.9% expressed hesitancy towards the COVID-19 vaccine. We assessed the impact of socio-demographic factors and previous vaccine behavior on vaccine intent; after adjustment of the multivariable logistic regression model, non-Barbadian nationality and previous flu vaccine uptake were statistically significant predictors of reported intent to take the COVID-19 vaccine. Persons who indicated that they would take the vaccine had a higher mean vaccine literacy score [3.46 95% CI (3.40, 3.52)] than those who were not ready to take the vaccine immediately [3.23 95% CI (3.15, 3.30)]. VL scores were higher among the 29.5% of HCPs who believed vaccines should be mandatory. CONCLUSION: This study highlighted vaccine hesitancy among HCPs in the sole public tertiary hospital of Barbados. As HCP perceptions may help or hinder the campaign to promote vaccine uptake in Barbados, vaccine promotion programs targeting HCPs are needed to ensure the success of the country's COVID-19 vaccination drive.
ABSTRACT
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies are an excellent indicator of past COVID-19 infection. As the COVID-19 pandemic progresses, retained sensitivity over time is an important quality in an antibody assay that is to be used for the purpose of population seroprevalence studies. We compared 5,788 health care worker (HCW) serum samples by using two serological assays (Abbott SARS-CoV-2 anti-nucleocapsid immunoglobulin G (IgG) and Roche anti-SARS-CoV-2 anti-nucleocapsid total antibody) and a subset of samples (all Abbott assay positive or grayzone, n = 485) on Wantai SARS-CoV-2 anti-spike antibody enzyme-linked immunosorbent assay (ELISA). For 367 samples from HCW with a previous PCR-confirmed SARS-CoV-2 infection, we correlated the timing of infection with assay results. Overall, seroprevalence was 4.2% on Abbott and 9.5% on Roche. Of those with previously confirmed infection, 41% (150/367) and 95% (348/367) tested positive on Abbott and Roche, respectively. At 21 weeks (150 days) after confirmed infection, positivity on Abbott started to decline. Roche positivity was retained for the entire study period (33 weeks). Factors associated (P ≤ 0.050) with Abbott seronegativity in those with previous PCR-confirmed infection included sex (odds ratio [OR], 0.30 male ; 95% confidence interval [CI], 0.15 to 0.60), symptom severity (OR 0.19 severe symptoms; 95% CI, 0.05 to 0.61), ethnicity (OR, 0.28 Asian ethnicity; 95% CI, 0.12 to 0.60), and time since PCR diagnosis (OR, 2.06 for infection 6 months previously; 95% CI, 1.01 to 4.30). Wantai detected all previously confirmed infections. In our population, Roche detected antibodies up to at least 7 months after natural infection with SARS-CoV-2. This finding indicates that the Roche total antibody assay is better suited than Abbott IgG assay to population-based studies. Wantai demonstrated high sensitivity, but sample selection was biased. The relationship between serological response and functional immunity to SARS-CoV-2 infection needs to be delineated. IMPORTANCE As the COVID-19 pandemic progresses, retained sensitivity over time is an important quality in an antibody assay that is to be used for the purpose of population seroprevalence studies. There is a relative paucity of published literature in this field to help guide public health specialists when planning seroprevalence studies. In this study, we compared results of 5,788 health care worker blood samples tested by using two assays (Roche and Elecsys, anti-nucleocapsid antibody) and by testing a subset on a third assay (Wantai enzyme-linked immunosorbent assay [ELISA] anti-spike antibody). We found significant differences in the performance of these assays, especially with distance in time from PCR-confirmed COVID-19 infection, and we feel these results may significantly impact the choice of assay for others conducting similar studies.