Iron deficiency and the effectiveness of the BNT162b2 vaccine for SARS-CoV-2 infection: A retrospective, longitudinal analysis of real-world data.

BACKGROUND: Iron plays a key role in human immune responses; however, the influence of iron deficiency on the coronavirus disease 2019 (COVID-19) vaccine effectiveness is unclear. AIM: To assess the effectiveness of the BNT162b2 messenger RNA COVID-19 vaccine in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19-related hospitalization and death in individuals with or without iron deficiency. METHODS: This large retrospective, longitudinal cohort study analyzed real-world data from the Maccabi Healthcare Services database (covering 25% of Israeli residents). Eligible adults (aged ≥16 years) received a first BNT162b2 vaccine dose between December 19, 2020, and February 28, 2021, followed by a second dose as per approved vaccine label. Individuals were excluded if they had SARS-CoV-2 infection before vaccination, had hemoglobinopathy, received a cancer diagnosis since January 2020, had been treated with immunosuppressants, or were pregnant at the time of vaccination. Vaccine effectiveness was assessed in terms of incidence rates of SARS-CoV-2 infection confirmed by real-time polymerase chain reaction assay, relative risks of COVID-19-related hospitalization, and mortality in individuals with iron deficiency (ferritin <30 ng/mL or transferrin saturation <20%). The two-dose protection period was Days 7 to 28 after the second vaccination. RESULTS: Data from 184,171 individuals with (mean [standard deviation; SD] age 46.2 [19.6] years; 81.2% female) versus 1,072,019 without (mean [SD] age 46.9 [18.0] years; 46.2% female) known iron deficiency were analyzed. Vaccine effectiveness in the two-dose protection period was 91.9% (95% confidence interval [CI] 83.7-96.0%) and 92.1% (95% CI 84.2-96.1%) for those with versus without iron deficiency (P = 0.96). Of patients with versus without iron deficiency, hospitalizations occurred in 28 and 19 per 100,000 during the reference period (Days 1-7 after the first dose), and in 19 and 7 per 100,000 during the two-dose protection period, respectively. Mortality rates were comparable between study groups: 2.2 per 100,000 (4/181,012) in the population with iron deficiency and 1.8 per 100,000 (19/1,055,298) in those without known iron deficiency. CONCLUSIONS: Results suggest that the BNT162b2 COVID-19 vaccine is >90% effective in preventing SARS-CoV-2 infection in the 3 weeks after the second vaccination, irrespective of iron-deficiency status. These findings support the use of the vaccine in populations with iron deficiency.

Risk factors, health outcomes, healthcare services utilization, and direct medical costs of patients with long COVID.

OBJECTIVES: Data on the economic burden of long COVID are scarce. We aimed to examine the prevalence and medical costs of treating long COVID. METHODS: We conducted this historical cohort study using data from patients with COVID-19 among members of a large health provider in Israel. Cases were defined according to physician diagnosis (definite long COVID) or suggestive symptoms given ≥ 4 weeks from infection (probable cases). Healthcare resource utilization and direct healthcare costs (HCCs) in the period before infection and afterward were compared across study groups. RESULTS: Between March 2020, and March 2021, a total of 180,759 COVID-19 patients (mean [SD] age = 32.9 years [19.0 years]; 89,665 [49.6%] females) were identified. Overall, 14,088 (7.8%) individuals developed long COVID (mean [SD] age = 40.0 years [19.0 years]; 52.4% females). Among them, 1477(10.5%) were definite long COVID and 12,611(89.5%) were defined as probable long COVID. Long COVID was associated with age (adjusted odds ratio [AOR] = 1.058 per year, 95% CI: 1.053-1.063), female sex (AOR = 1.138; 95% CI: 1.098-1.180), smoking (AOR = 1.532; 95% CI: 1.358-1.727), and symptomatic acute phase (AOR = 1.178; 95% CI: 1.133-1.224), primarily muscle pain and cough. Hypertension was an important risk factor for long COVID among younger adults. Compared with patients with non-long COVID, definite and probable cases were associated with AORs of 2.47 (2.22-2.75) and 1.76 (1.68-1.84) for post-COVID hospitalization, respectively. Although among patients with non-long COVID HCCs decreased from $1400 during 4 months before the infection to $1021 and among patients with long COVID, HCCs increased from $2435 to $2810. CONCLUSION: Long COVID is associated with a substantial increase in the utilization of healthcare services and direct medical costs. Our findings underline the need for timely planning and allocating resources for patient-centered care for patients with long COVID as well as for its secondary prevention in high-risk patients.

Assessment of Effectiveness of 1 Dose of BNT162b2 Vaccine for SARS-CoV-2 Infection 13 to 24 Days After Immunization.

Importance: The BNT162b2 vaccine showed high efficacy against COVID-19 in a phase III randomized clinical trial. A vaccine effectiveness evaluation in a real-world setting is needed. Objective: To assess the short-term effectiveness of the first dose of the BNT162b2-vaccine against SARS-CoV-2 infection 13 to 24 days after immunization in a real-world setting. Design, Setting, and Participants: This comparative effectiveness study used data from a 2.6 million-member state-mandated health care system in Israel. Participants included all individuals aged 16 years and older who received 1 dose of the BNT162b2 vaccine between December 19, 2020, and January 15, 2021. Data were analyzed in March 2021. Exposure: Receipt of 1 dose of the BNT162b2 vaccine. Main Outcomes and Measures: Information was collected regarding medical history and positive SARS-CoV-2 polymerase chain reaction test and COVID-19 symptoms from 1 day after first vaccine to January 17, 2021. Daily and cumulative infection rates in days 13 to 24 were compared with days 1 to 12 after the first dose using Kaplan-Meier survival analysis and generalized linear models. Results: Data for 503 875 individuals (mean [SD] age, 59.7 [14.7] years; 263 228 [52.4%] women) were analyzed, of whom 351 897 had follow-up data for days 13 to 24. The cumulative incidence of SARS-CoV-2 infection was 2484 individuals (0.57%) during days 1 through 12 and 614 individuals (0.27%) in days 13 through 24. The weighted mean (SE) daily incidence of SARS-CoV-2 infection in days 1 through 12 was 43.41 (12.07) infections per 100 000 population and 21.08 (6.16) infections per 100 000 population in days 13 through 24, a relative risk reduction (RRR) of 51.4% (95% CI, 16.3%-71.8%). The decrease in incidence was evident from day 18 after the first dose. Similar RRRs were calculated in individuals aged 60 years or older (44.5%; 95% CI, 4.1%-67.9%), those younger than 60 years (50.2%; 95% CI, 14.1%-71.2%), women (50.0%; 95% CI, 13.5%-71.0%), and men (52.1%; 95% CI, 17.3%-72.2%). Findings were similar in subpopulations (eg, ultraorthodox Jewish: RRR, 53.5% [95% CI, 19.2%-73.2%]) and patients with various comorbidities (eg, cardiovascular diseases: RRR, 47.2% [95% CI, 7.8%-69.8%]). Vaccine effectiveness against symptomatic COVID-19 was 54.4% (95% CI, 21.4%-73.6%). Conclusions and Relevance: In this comparative effectiveness study of a single dose of the BNT162b2 vaccine, results were comparable to that of the phase III randomized clinical trial.

The Effectiveness of the Two-Dose BNT162b2 Vaccine: Analysis of Real-World Data.

BACKGROUND: Coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccines were shown to be highly efficacious in preventing the disease in randomized controlled trials; nonetheless, evidence on the real-world effectiveness of this vaccine is limited. Study objective was to evaluate the effectiveness of BNT162b2 vaccine in preventing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and COVID-19-related hospitalization and mortality. METHODS: This historical cohort study included members of a large health provider in Israel that were vaccinated with at least 1 dose of BNT162b2. The primary outcome was incidence rate of a SARS-CoV-2 infection confirmed with real-time polymerase chain reaction (rt-PCR), between 7 and 27 days after second dose (protection-period), as compared to days 1-7 after the first dose, where no protection by the vaccine is assumed (reference-period). RESULTS: Data of 1 178 597 individuals vaccinated with BNT162b2 were analyzed (mean age 47.7 years [SD = 18.1], 48.4% males) of whom 872 454 (74.0%) reached the protection period. Overall, 4514 infections occurred during the reference period compared to 728 during the protection period, yielding a weighted mean daily incidence of 54.8 per 100 000 (95% confidence interval [CI]: 26.1-115.0 per 100 000) and 5.4 per 100 000 (95% CI: 3.5-8.4 per 100 000), respectively. The vaccine effectiveness in preventing infection was 90% (95% CI: 79%-95%) and 94% (95% CI: 88%-97%) against COVID-19. Among immunosuppressed patients, vaccine effectiveness against infection was 71% (95% CI: 37%-87%). The adjusted hazard ratios for hospitalization in those infected were 0.82 (95% CI: .36-1.88), 0.45 (95% CI: .23-.90), and 0.56 (95% CI: .36-.89) in the age groups 16-44, 45-64. and ≥75 years, respectively. CONCLUSIONS: The effectiveness of the BNT162b2 vaccine is comparable to the one reported in the phase III clinical trial.