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

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.

Immunogenicity evaluation of ChAdox1 nCov-19 (AZD1222) vaccine in solid cancer patients in Chulabhorn Hospital.

INTRODUCTION: Cancer patients are more vulnerable to coronavirus disease 2019 (COVID-19) owing to their compromised immune status. However, data regarding COVID-19 vaccine safety and immune response in cancer patients are scarce. METHOD: This prospective, age- and sex-matched, single-center cohort study included 61 cancer patients and 122 healthy control participants. Seropositivity was defined as anti-S IgG titer >0.8 units/ml. Primary end point was seroconversion rate of immunoglobulin (Ig)G antibodies against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike (S) protein (anti-S IgG) in cancer patients vs. healthy control participants following the second dose of COVID-19 vaccine ChAdOx1 nCoV-19 (AZD1222). RESULTS: After the second-dose vaccination, there was no difference in seropositivity rate between groups (57 [93.44%] patients with cancer vs. 121 [99.18%] control participants; geometric mean ratio [GMR]: 0.39; 95%CI: 0.01-10.46; p-value = 0.571). In contrast, after the first-dose vaccination, the seropositivity rate was significantly lower in the cancer patients than in the control participants (50/61 [81.97%] vs. 121/122 [99.18%]; GMR: 0.07; 95%CI: 0.01-0.71; p = 0.025). The median anti-S IgG titer after the first-and second dose vaccination were not significantly different between groups. Female sex was significantly associated with a higher anti-S IgG titer. 5FU- and taxane-based chemotherapy regimens were associated with a lower IgG titer. Side effects of vaccination were tolerable. CONCLUSIONS: The anti-S IgG seropositivity rate after completing the second vaccine dose did not differ between the cancer patients and control participants. However, the anti-S IgG seropositivity rate after the first-dose vaccination was lower in cancer patients.