Immunogenicity and risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection after Coronavirus Disease 2019 (COVID-19) vaccination in patients with cancer: a systematic review and meta-analysis

Abstract

Background: Patients with cancer are considered a priority group for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccination given their high risk of contracting severe Coronavirus Disease 2019 (COVID-19). However, limited data exist regarding the efficacy of immunisation in this population. In this study, we assess the immunologic response after COVID-19 vaccination of cancer versus non-cancer population.

Methods: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases were searched from 01st March 2020 through 12th August 12 2021. Primary end-points were anti-SARS-CoV-2 spike protein (S) immunoglobulin G (IgG) seroconversion rates, T-cell response, and documented SARS-CoV-2 infection after COVID-19 immunisation. Data were extracted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Overall effects were pooled using random-effects models.

Results: This systematic review and meta-analysis included 35 original studies. Overall, 51% (95% confidence interval [CI], 41-62) and 73% (95% CI, 64-81) of patients with cancer developed anti-S IgG above the threshold level after partial and complete immunisation, respectively. Patients with haematologic malignancies had a significantly lower seroconversion rate than those with solid tumours after complete immunisation (65% vs 94%; P < 0.0001). Compared with non-cancer controls, oncological patients were less likely to attain seroconversion after incomplete (risk ratio [RR] 0.45 [95% CI 0.35-0.58]) and complete (RR 0.69 [95% CI 0.56-0.84]) COVID-19 immunisation schemes. Patients with cancer had a higher likelihood of having a documented SARS-CoV-2 infection after partial (RR 3.21; 95% CI 0.35-29.04) and complete (RR 2.04; 95% CI 0.38-11.10) immunisation.

Conclusions: Patients with cancer have an impaired immune response to COVID-19 vaccination compared with controls. Strategies that endorse the completion of vaccination schemes are warranted. Future studies should aim to evaluate different approaches that enhance oncological patients' immune response.

Keywords: COVID-19 breakthrough infections; COVID-19 vaccines; Haematologic neoplasms; Immunogenicity; Neoplasms; SARS-CoV-2; Vaccines.

Fig. 1

The PRISMA flowchart summarising the process for the identification of eligible studies. Abbreviations: COVID-19, Coronavirus Disease 2019; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Fig. 2

Rates of seroconversion in patients with cancer as per the vaccination regimen. Squares represent indirect effect size (Risk ratio [RR]). Horizontal lines indicate 95% Confidence Interval (CI). Diamonds indicate the meta-analytic pooled RR, calculated separately by vaccination scheme (i.e., partial or complete), and the overall pooled RR (95%CI) in patients with cancer.

Fig. 3

Rates of seroconversion in oncological patients versus non-cancer controls as per vaccination scheme. Squares represent indirect effect size (Risk ratio [RR]). Horizontal lines indicate 95% Confidence Interval (CI). Diamonds indicate the meta-analytic pooled RR, calculated separately by vaccination scheme (i.e., partial or complete), and the overall pooled RR (95%CI) in patients with cancer.

Fig. 4

Rates of seroconversion in patients with solid malignancies versus non-cancer controls as per vaccination scheme. Squares represent indirect effect size (Risk ratio [RR]). Horizontal lines indicate 95% Confidence Interval (CI). Diamonds indicate the meta-analytic pooled RR, calculated separately by vaccination scheme (i.e., partial or complete), and the overall pooled RR (95%CI) in patients with cancer.

Fig. 5

Rates of seroconversion in patients with haematological malignancies versus non-cancer controls as per vaccination scheme. Squares represent indirect effect size (Risk ratio [RR]). Horizontal lines indicate 95% Confidence Interval (CI). Diamonds indicate the meta-analytic pooled RR, calculated separately by vaccination scheme (i.e., partial or complete), and the overall pooled RR (95%CI) in patients with cancer.

Fig. 6

Rates of seroconversion in patients with haematological versus solid malignancies and incomplete COVID-19 vaccination regimen. Squares represent indirect effect size (Risk ratio [RR]). Horizontal lines indicate 95% Confidence Interval (CI). Diamonds indicate the meta-analytic pooled RR, calculated separately by vaccination scheme (i.e., partial or complete), and the overall pooled RR (95%CI) in patients with cancer. COVID-19, Coronavirus Disease 2019.

Fig. 7

Rates of seroconversion in patients with haematologic versus solid malignancies and complete COVID-19 vaccination regimen. Squares represent indirect effect size (Risk ratio [RR]). Horizontal lines indicate 95% Confidence Interval (CI). Diamonds indicate the meta-analytic pooled RR, calculated separately by vaccination scheme (i.e., partial or complete), and the overall pooled RR (95%CI) in patients with cancer. COVID-19, Coronavirus Disease 2019.

Fig. 8

Rates of SARS-CoV-2 infection in oncological patients after vaccination compared with controls. Squares represent indirect effect size (Risk ratio [RR]). Horizontal lines indicate 95% Confidence Interval (CI). Diamonds indicate the meta-analytic pooled RR, calculated separately by vaccination scheme (i.e., partial or complete), and the overall pooled RR (95%CI) in patients with cancer. SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus 2.