Serological response to a third booster dose of BNT162b2 COVID-19 vaccine among seronegative cancer patients.

BACKGROUND AND AIM: The BNT162b2 COVID-19 vaccine (Pfizer/BioNTech), given as a two-dose series, 3 weeks apart, elicits a serological response in 84-98% of patients with cancer, even if administered while undergoing anticancer treatments. Herein, we report the impact of a third (booster) dose of BNT162b2, delivered 6 months following the second vaccine dose. METHODS: This pilot study included four patients with cancer who were seronegative after two vaccine doses, and received a third (booster) dose of BNT162b2 at 6 months following the second vaccine dose. The four patients received the three vaccine doses between December 2020 and July 2021. Samples were evaluated with an enzyme-linked immunosorbent assay (ELISA) that detects IgG (Immunoglobulin G) antibodies against the RBD (receptor-binding domain) of SARS-CoV-2. RESULTS: At a mean time of 19 days (ranges 7-28) after the second vaccination, all four patients were seronegative for RBD-IgG. However, at a mean time of 21 days (ranges 20-22) after the third dose, three out of the four patients (75%) were now seropositive. Mean RBD-IgG titers were increased after the third vaccine dose from 0.37 to 2.81 (Student's t-test, p = 0.05, two-sided). CONCLUSIONS: Although limited by the small sample size, our findings suggest that a third (booster) dose administered to patients with cancer, who remain seronegative despite two doses of BNT162b2, may be efficacious in eliciting an antibody response.

Cardiovascular adverse events associated with hydroxychloroquine and chloroquine: A comprehensive pharmacovigilance analysis of pre-COVID-19 reports.

AIM: There is a clinical need for safety data regarding hydroxychloroquine (HCQ) and chloroquine (CQ) during the coronavirus (COVID-19) pandemic. We analysed real-world data using the U.S. Food and Drug Administration Adverse Events Reporting System (FAERS) database to assess HCQ/CQ-associated cardiovascular adverse events (CVAEs) in pre-COVID-19 reports. METHODS: We conducted disproportionality analysis of HCQ/CQ in the FAERS database (07/2014-9/2019), using reporting odds ratio (ROR) and the lower bound of the information component 95% credibility interval (IC025 ). RESULTS: The full database contained 6 677 225 reports with a mean (±SD) age of 53 (±17) years and 74% females. We identified 4895 reports of HCQ/CQ related adverse events, of which 696 (14.2%) were CVAEs. Compared with the full database, HCQ/CQ use was associated with a higher reporting rate of major CVAEs, including cardiomyopathy (n = 86 [1.8%], ROR = 29.0 [23.3-35.9]), QT prolongation (n = 43 [0.9%], ROR = 4.5 [3.3-6.1]), cardiac arrhythmias (n = 117 [2.4%], ROR = 2.2 [1.8-2.7]) and heart failure (n = 136 [2.8%], ROR = 2.2 [1.9-2.7], all IC025 > 0). No statistically significant differences were observed between sex and age groups. CVAEs were reported more often in patients with systemic lupus erythematosus and Sjogren's syndrome. HCQ/CQ-associated CVAEs demonstrated subsequent hospitalization and mortality rates of 39% and 8%, respectively. Overdose reports demonstrated an increased frequency of QT prolongation and ventricular arrhythmias (35% and 25%, respectively). CONCLUSION: In a real-world setting, HCQ/CQ treatment is associated with higher reporting rates of various CVAEs, particularly cardiomyopathy, QT prolongation, cardiac arrhythmias and heart failure. HCQ/CQ-associated CVAEs result in high rates of severe outcomes and should be carefully considered as an off-label indication, especially for patients with cardiac disorders.