Immunogenicity of two doses of inactive COVID-19 vaccine and third booster dose mRNA vaccine in patients with cancer receiving active systemic therapy.

We aimed to evaluate the seroconversion rates after two doses of inactive COVID-19 vaccine (CoronaVac) and the benefit of a third dose mRNA vaccine booster in patients with cancer receiving active treatment. Patients with solid tumors receiving active treatment (n = 101) and patients with no-cancer (n = 48) as the control group were included in the study. All the patients and controls had received two doses of CoronaVac and a third booster dose of the mRNA vaccine (Bnt162b2). Anti-SARS-CoV-2 Spike Receptor Binding Domain IgG antibody levels after the second and third dose were measured with quantitative ELISA. The median age of the patients was 66 (IQR 60-71). 79% of the patients were receiving chemotherapy, and 21% were receiving immunotherapy at the time of vaccination. Antibody levels measured after two doses of CoronaVac were significantly lower in patients with cancer than in the control group (median 0 µg/ml [IQR 0-1.17 µg/ml] vs median 0.91 µg/ml [IQR 0-2.24 µg/ml], respectively, P = .002). Seropositivity rates were 46.5% in patients with cancer and 72.9% in the control group (P = .002). Antibody measurement was performed in 26 patients after the third dose. Seroconversion rate increased from 46.5% to 88.5% (P < .001), and the antibody titers significantly increased with the third-dose booster (median 0 µg/ml [IQR 0-1.17 µg/ml] after two doses vs 12.6 µg/ml [IQR 1.8-69.1 µg/ml] after third booster dose, P < .001). Immunogenicity of CoronaVac is low in patients with cancer receiving active treatment, and administering a third dose of an mRNA vaccine is effective in terms of improving seroconversion rates.

Clinical features and outcomes of COVID-19 in patients with solid tumors: Turkish National Registry Data.

We present demographic, clinical, laboratory characteristics and outcomes of the patients with solid malignancies and novel coronavirus disease (COVID-19) collected from the National COVID-19 Registry of Turkey. A total of 1523 patients with a current or past diagnosis of solid tumors and diagnosed with COVID-19 (confirmed with PCR) between 11 March and 20 May 2020 were included. The primary outcome was 30-day mortality. Median age was 61 (range: 18-94), and 752 (49%) were male. The most common types of cancers were breast (19.8%), prostate (10.9%) and colorectal cancer (10.8%). 65% of the patients had at least one comorbidity. At least one COVID-19-directed therapy was given in 73% of the patients.. Hospitalization rate of the patients was 56.6% and intensive care unit admission rate was 11.4%. Seventy-seven (5.1%) patients died within 30 days of diagnosis. The first multivariate model which included only the demographic and clinical characteristics showed older age, male gender and presence of diabetes and receipt of cytotoxic therapy to be associated with increased 30-day mortality, while breast and prostate cancer diagnoses were associated with lower 30-day mortality. In the second set, we further included laboratory parameters. The presence of leukocytosis (OR 6.7, 95% CI 3.3-13.7, P < .001), lymphocytopenia (OR 3,1, 95% CI 1,6-6,1, P = .001) and thrombocytopenia (OR 3,4 95% CI 1,5-8,1, P = .005) were found to be associated with increased 30-day mortality. Relatively lower mortality compared to Western countries and China mainly results from differences in baseline risk factors but may also implicate the importance of intensive supportive care.