Difference in Immunogenic Responses to COVID-19 Vaccines in Patients With Cancer Receiving Chemotherapy Versus Nonchemotherapy Treatment

Abstract

Purpose: The COVID-19 pandemic has affected public health worldwide. The efficacy and safety of COVID-19 vaccines have been evaluated in the general population; however, data on patients with malignancies are limited.

Methods: This prospective longitudinal observational cohort study was conducted between June and July 2021. Enrolled adult patients with cancer were divided into chemotherapy and nonchemotherapy groups. All participants were immunized with two doses of the ChAdOx1 nCoV-19 or CoronaVac COVID-19 vaccines. The primary outcome was a comparison of the immunogenicity (as assessed by spike protein [anti-S] immunoglobulin G [IgG] antibody titers) of two doses of COVID-19 vaccine in the chemotherapy and nonchemotherapy groups. The secondary outcomes included the anti-S IgG seroconversion rate and vaccine safety in both groups.

Results: Among the 173 enrolled patients with solid cancer, after COVID-19 vaccination, the chemotherapy group had a significantly lower median anti-S IgG titer than the nonchemotherapy group (26 v 237 U/mL, P < .001). A statistically significant difference in anti-S IgG titer was found between groups vaccinated with CoronaVac (7 v 90 U/mL, P < .001), but no difference was found in those vaccinated with ChAdOx1 nCoV-19 (818 v 1061 U/mL, P = .075). The anti-S IgG seroconversion rate was significantly lower in the chemotherapy group than that in the nonchemotherapy group (78.9% v 96.5%, P = .001). No new or serious vaccine-related adverse events were reported.

Conclusion: Patients with solid cancer receiving a COVID-19 vaccine while undergoing chemotherapy had lower immunogenicity responses to vaccination than those who were vaccinated while undergoing nonchemotherapy treatment. No statistically significant difference was observed in the COVID-19 vaccine safety profiles between groups.

Trial registration: ClinicalTrials.gov TCTR20221001004.

FIG 1

CONSORT diagram. CCRT, concurrent chemoradiotherapy; CMT, chemotherapy; complete vaccination, two doses of the ChAdOx1 nCoV-19 or CoronaVac vaccine; non-CMT, nonchemotherapy.

FIG 2

Anti–SARS-CoV-2 RBD IgG levels before and after COVID-19 vaccination (all vaccine). The anti–SARS-CoV-2 RBD IgG levels in patients in CMT and non-CMT treatment groups were zero at baseline. At 4 weeks after two-dose vaccination, the anti–SARS-CoV-2 RBD IgG levels in patients receiving CMT were 26 U/mL and 267 U/mL in non-CMT treatment (P < .001). CMT, chemotherapy; IgG, immunoglobulin G; IQR, interquartile range; non-CMT, nonchemotherapy; RBD, receptor-binding domain.

FIG 3

Anti–SARS-CoV-2 RBD IgG levels before and after COVID-19 vaccination (ChAdOx1 and CoronaVac vaccine). In the ChAdOx1 vaccination group (left), there was no difference in the anti–SARS-CoV-2 S RBD IgG levels at 4 weeks after completing vaccination between chemotherapy and nonchemotherapy groups, 818 and 1,061 U/mL, respectively (P = .075). Patients receiving the CoronaVac vaccination (right) showed a statistically significant difference in anti–SARS-CoV-2 RBD IgG levels between the two groups, 7 U/mL in the CMT group and 90 U/mL in the non-CMT group (P < .001). CMT, chemotherapy; IgG, immunoglobulin G; IQR, interquartile range; NA, not available; non-CMT, nonchemotherapy; RBD, receptor-binding domain.

FIG 4

Anti–SARS-CoV-2 IgG seroconversion rates after COVID-19 vaccination (all vaccine). The anti–SARS-CoV-2 IgG seroconversion rates between the CMT and non-CMT groups at 4 weeks after two-dose vaccination were 78.9% (95% CI, 68.1 to 87.5) and 96.5% (95% CI, 80.1 to 99.3), respectively, P = .001. The grey bars indicate 95% CIs. CMT, chemotherapy; IgG, immunoglobulin G; non-CMT, nonchemotherapy.

FIG 5

Anti–SARS-CoV-2 IgG seroconversion rates after COVID-19 vaccination (ChAdOx1 and CoronaVac vaccine). In the ChAdOx1 vaccination group (left), the anti–SARS-CoV-2 IgG seroconversion rate in the non-CMT group was significantly higher than that in the CMT group at weeks 8 and 12 (P = .002 and P = .019), whereas the seroconversion rate at week 16 showed no difference. There were 88.6% (95% CI, 73.3 to 96.8) in the CMT group and 97.9% (95% CI, 88.7 to 99.9) in the non-CMT group, P = .436. In the CoronaVac vaccination group (right), the anti–SARS-CoV-2 IgG seroconversion rate in the non-CMT group was significantly higher than that in the CMT group (94.9% [95% CI, 82.7 to 99.4] and 70.7% [95% CI, 54.5 to 83.9], respectively; P = .007). The grey bars indicate 95% CIs. CMT, chemotherapy; IgG, immunoglobulin G; non-CMT, nonchemotherapy.