ABSTRACT
Background: Recent studies reported poor to moderate humoral response after two vaccine doses in heart transplant recipients (HTR). Currently, French healthcare authorities recommend 2 and 3 vaccine injections for transplant recipients with and without prior SARS-CoV-2 infection, respectively. This study aimed to evaluate level and durability of humoral immunity with this vaccination strategy. Methods: This single-center cohort study included HTR followed at Paris Bichat hospital between January 2020 and September 2021. Analyses were performed using automated immunoassays (Abbot) to quantify anti-spike IgG (cut-off ≥ 7.1 BAU/mL) and anti-nucleocapsid IgG (cut-off index > 0.49), respectively. Categorical variables were described as number (%) and continuous variables with median (IQR). Results: A total of 181 HTR (75.7% males, age 58 y [47-66]) transplanted between June 1990 and June 2021, with cardiomyopathy (n=95), coronary artery disease (n=61), valvular cardiomyopathy (n=19) or other transplant indications were included. Median time from transplantation to first vaccine dose was 4.2 y [1.8-6.6]. 143 HTR (79%) had no SARS-CoV-2 infection history (HTRn) and 38 (21%) contracted the infection (HTRi) (56% before and 42% after vaccination initiation). After 2 vaccine injections, anti-S IgG seroconversion was observed for only 16% (n=12/76) of HTRn. Overall, anti-S IgG titers were lower in HTRn than in HTRi (0.5 [0.2-2.6] vs 578 [1.4-4449] BAU/mL, respectively, p=0.0001). The 3rd vaccine dose enabled to obtain 42% (n=33/72) of seroconversion among HTRn with median anti-S titers of 3.2 BAU/mL [0.4-35.0]. Only half seroconverters HTRn reached the 260 BAU/mL cut-off chosen by French authorities to define vaccination efficacy. Interestingly, these patients seem to have a sustained humoral response 4 months after the 3rd dose. Conclusion: This study gives new insights on the effect of the 3rd vaccine dose in HTR with low rate of seroconversion and low titers of anti-S IgG but sustained humoral response when seroconversion occurs. Studies on vaccine efficacy against SARS-CoV-2 variants and cell-mediated immune response in this cohort are ongoing.
ABSTRACT
A meta-analysis of the Chinese studies in April 2020, including 3600 patients with cancer and COVID-19, first reported an increase of the COVID-19 risk and the case-fatality in these patients. Then, North-American and European series confirmed the increased COVID-19 risk for patients with cancer, as the increased risk of severe COVID-19 and death, when compared with general population, adjusting for age. Patients with lung cancer have the highest risk of severe respiratory forms, and the highest risk of SARS-CoV2-induced death (25 to 30%), after patients with hematological cancers. Metastatic patients, with poor PS, and those having received a cytotoxic chemotherapy within the weeks preceding SARSCoV2 infection, are those with the highest risk of death. Conversely, being treated with immune checkpoint inhibitors would not favor the cytokine storm, which makes the severity of COVID-19. SARS-CoV2 pandemic, beyond having needed the generalization of drastic social distancing measures in hospitals, also needed organizational changes, to allow healthcare continuity for cancer patients. Adaptation of therapeutic protocols was needed, with increased intervals between cycles, the choice of less toxic protocols, the systematic use of hematological growth factors, and teleconsultations follow-up. Lastly, mRNA-based SARS-CoV2 vaccines are efficient in patients with thoracic cancer, provided the interval of 21/28 days between the two injections is maintained, since protective immunization seems delayed, especially after cytotoxic chemotherapy. Only 13% of patients with very low protective antibodies titers would need a third booster injection, with a clear rise in protective antibodies titers induced by such a third injection.© 2021 SPLF. Published by Elsevier Masson SAS. All rights reserved.