Vaccination Of Cancer Patients Research Articles

COVID-19 vaccination in cancer patients: Immune responses one year after the third dose

Cancer patients (CPs), being immunosuppressed due to the treatment received or to the disease itself, are more susceptible to infections and their potential complications, showing therefore an increased risk of developing severe COVID-19 compared to the general population.We evaluated the immune responses to anti-SARS-CoV-2 vaccination in patients with solid tumors one year after the administration of the third dose and the effect of cancer treatment on vaccine immunogenicity was assessed. Healthy donors (HDs) were enrolled. Binding and neutralizing antibody (Ab) titers were evaluated using chemiluminescence immunoassay (CLIA) and Plaque Reduction Neutralization Test (PRNT) respectively. T-cell response was analyzed using multiparametric flow cytometry.CPs who were administered three vaccine doses showed lower Ab titers than CPs with four doses and HDs. Overall, a lower cell-mediated response was found in CPs, with a predominance of monofunctional T-cells producing TNFα. Lower Ab titers and a weaker T-cell response were observed in CPs without prior SARS-CoV-2 infection when compared to those with a previous infection. While no differences in the humoral response were found comparing immunotherapy and non-immunotherapy patients, a stronger T-cell response in CPs treated with immunotherapy was observed.Our results emphasize the need of booster doses in cancer patients to achieve a level of protection similar to that observed in healthy donors and underlines the importance of considering the treatment received to reach a proper immune response.

Effectiveness of COVID-19 vaccines against severe outcomes in cancer patients: Real-world evidence from self-controlled risk interval and retrospective cohort studies

BackgroundThe effectiveness of COVID-19 vaccines is generally reduced in cancer patients compared to the general population. However, there are only a few studies that compare the relative risk of breakthrough infections and severe COVID-19 outcomes in fully vaccinated cancer patients versus their unvaccinated counterparts. MethodsTo assess the effectiveness of COVID-19 vaccines in cancer patients, we employed (1) a self-controlled risk interval (SCRI) design, and (2) a retrospective matched cohort design. A SCRI design was used to compare the risk of breakthrough infection in vaccinated cancer patients during the period immediately following vaccination (“control window”) and the period in which immunity is achieved (“exposure windows”). The retrospective matched cohort design was used to compare the risk of severe COVID-19 outcomes between vaccinated and unvaccinated cancer patients. For both studies, data were extracted from the Korea Disease Control and Prevention Agency-COVID-19-National Health Insurance Service cohort, including demographics, medical history, and vaccination records of all individuals confirmed with COVID-19. We used conditional Poisson regression to calculate the incidence rate ratio (IRR) for breakthrough infection and Cox regression to estimate the hazard ratio (HR) for severe outcomes. ResultsOf 14,448 cancer patients diagnosed with COVID-19 between October 2020 and December 2021, a total of 217 and 3996 cancer patients were included in the SCRI and cohort study respectively. While the risk of breakthrough infections, measured by the incidence rate in the control and exposure windows, did not show statistically significant difference in vaccinated cancer patients (IRR=0.88, 95% CI: 0.64–1.22), the risk of severe COVID-19 outcomes was significantly lower in vaccinated cancer patients compared to those unvaccinated (HR=0.27, 95% CI: 0.22–0.34). ConclusionCOVID-19 vaccines significantly reduce the risk of severe outcomes in cancer patients, though their efficacy against breakthrough infections is less evident.

Cross-sectional survey evaluating the psychological impact of the COVID-19 vaccination campaign in patients with cancer: The VACCINATE study.

The COVID-19 pandemic has profoundly impacted on cancer patients' psychological well-being and clinical status. We assessed the levels of anxiety, depression, and distress and the attitude towards COVID-19 vaccination in cancer patients, accepting vaccination at the Verona University Hospital and Camposampiero Hospital in the Veneto region. Self-reported questionnaires were administered to patients undergoing COVID-19 vaccination between March and May 2021 (first and second dose). Twenty-seven items were investigated: i) demographics/clinical characteristics; ii) anxiety, depression, and distress (Hospital Anxiety and Depression Scale-HADS-and Distress Thermometer-DT); iii) four specific items regarding awareness about infection risks, interference with anticancer treatments, and vaccine side effects. Sixty-two and 57% of the patients who accepted to be vaccinated responded to the survey in the two participating Hospitals, respectively. Mean age was 63 years (SD: 12 years; range 19-94 years), women were slightly more prevalent (57.6%), most participants were married (70%), and either worker or retired (60%). Borderline and clinical levels of anxiety were recorded in 14% and 10% of respondents; borderline and clinical levels of depression in 14% and 8%; and moderate and severe distress levels in 33% and 9%. Overall, there was high confidence that vaccination would reduce the risk of contracting COVID-19 (70%), which would make patients feel less worried about contracting the infection (60%). Fear that vaccine-related side effects would interfere with anticancer treatment and/or global health status was low (10% and 9% for items 3 and 4, respectively) and significantly associated with baseline levels of anxiety, depression, and distress at multivariate analysis. Results did not differ between the Verona and Camposampiero cohorts. During the COVID-19 vaccination campaign, adult cancer patients demonstrated high levels of confidence towards vaccination; baseline levels of anxiety, depression, and distress were the only significant predictors of reduced confidence.

Humoral Response and Safety after a Fourth Dose of the SARS-CoV-2 BNT162b2 Vaccine in Cancer Patients Undergoing Active Treatment-Results of a Prospective Observational Study.

Only a few studies have been carried out on the efficacy and safety of a fourth dose of the COVID-19 vaccine in patients with cancer. In this prospective observational study, we aimed to assess the serological response and safety of the fourth booster shot of the BNT162b2 vaccine in 79 cancer patients, vaccinated between 1 March and 25 August 2022, under systemic anticancer therapy. The primary endpoint was to assess the increase in the anti-SARS-CoV-2 antibodies; secondary endpoints were the vaccine safety and side effects. Consequently, 40 patients (50.63%) revealed the maximum detection values in their IgG titers before the fourth dose of the vaccine, while 39 patients (49.37%) did not. Primary endpoint: Of 39 patients, 36 (92.31%) showed a significant increase in the anti-SARS-CoV-2 IgG titers, and 32 of them (82.05%) reached the maximum titration values. Secondary endpoints: The most common adverse events were mild in severity and included injection site pain, erythema and tiredness. The majority of the adverse reactions reported were grade 1 and no grade 3 and 4 reactions were detected. Our data provide evidence that a fourth dose of the BNT162b2 anti-SARS-CoV-2 vaccine is effective and safe in patients with solid tumors in active anticancer treatment.

The Protective Effect of the COVID-19 Vaccine in Cancer Patients

The novel coronavirus pneumonia pandemic has led to bad engulf on public health worldwide. Widespread vaccination with SARS-CoV-2 vaccine (COVID-19 vaccine) has become one of the most potentially effective strategy of ending the epidemic and avoiding the public suffering from both physical and psychological pain. With weak autoimmunity and the complex body condition in different stages of treatment, cancer patients are more vulnerable and sensitive to infect in COVOD-19 pandemics. There are many data indicating that cancer patients usually obtain the higher mobidity, higher rate of the severe illness and higher fatality in COVID-19 pandemic. In that case, they are in greater need of protective measures, of which vaccination is the most convenient and widely accepted protective. Based on the existing clinical studies, this review aims to focus on the safety and efficacy of the COVID-19 vaccine in patients with cancer. After that the immunogenicity of the vaccine itself, adjuvant, doses, times of vaccinations and patient condition are listed to consider how they affet the effect of vaccine. Due to the complexity of the immune function of cancer patients, COVID-19 vaccination in cancer patients is extremely critical to protect from COVID-19 pneumonia, so large-scale clinical studies and real-world research data are still needed to develop a more refined and appropriate vaccination program to achieve better protection of oncology patients.

Serological response and immune-related adverse events following COVID-19 vaccination in cancer patients treated with immune checkpoint inhibitors: A systematic review and meta-analysis.

With the popularity of Coronavirus disease 2019 (COVID-19) vaccine and the development of vaccination strategies, the impact of COVID-19 vaccine on cancer patients receiving immune checkpoint inhibitors (ICIs) is still unclear. In the systematic review and meta-analysis of patients with ICIs, we assessed the serological response of cancer patients receiving COVID-19 vaccine, and explored the risk of immune related adverse events (irAEs). We searched PubMed, EMBASE and Cochrane Library as of 10 June 2023, and included cancer patients who received ICIs and COVID-19 vaccine. The systematic review and meta-analysis include cohort study, cross-sectional study and case report. The outcome included the serological response, Spike-specific T-cell response, irAEs and rare adverse events. When possible, the data were analysed by random effect analysis, and the statistical heterogeneity was assessed by Q-test and I2 statistics. We explored the sources of heterogeneity through L'Abbe plots, Galbraith radial plots, and sensitivity analysis. The publication bias was evaluated by Egger's, Begg's linear regression test and funnel plot, and the impact of publication bias was further analysed by trim and fill method. 27 studies were eligible (19 cohort studies, 1 cross-sectional study and 7 case reports), involving 8331 patients (with 4724 receiving ICIs). Most studies used mRNA vaccine (BNT162b2 or mRNA-1273). Compared with cancer patients receiving chemotherapy, cancer patients receiving ICIs were significantly more likely to have seroconversion (RR=1.05, 95%CI 1.01-1.10, P=0.02). There were no statistically significant differences in seroconversion rates when comparing cancer patients receiving ICIs with controls without cancer (RR=0.95, 95% CI 0.89-1.01, P=0.09) or with cancer patients receiving targeted therapy (RR=1.05, 95% CI 0.79-1.39, P=0.75). The incidence of irAEs in patients receiving ICIs before and after COVID-19 vaccination was (21.96%, 95%CI 16.66%-28.94%) and (14.88%, 95%CI 8.65%-25.57%), respectively. The most common irAEs were endocrine abnormalities, skin disorders, etc. The certainty of evidence was low in cancer patients with ICIs, compared with those receiving chemotherapy, and very low versus controls without cancer. Cancer patients treated with ICIs seem to be able to receive COVID-19 vaccine safely without increasing the incidence of irAEs.

COVID-19 Antibody Seroconversion in Cancer Patients: Impact of Therapy Cessation-A Single-Center Study.

The effective development of COVID-19 vaccination has mitigated its harm. Using two laboratory methods, we investigated the efficacy of the BNT162b2 mRNA and BBIBP-CorV COVID-19 vaccines on seroconversion rates in cancer patients undergoing active cancer treatment. SARS-CoV-2 vaccines were scheduled for 134 individuals. The consenting participants submitted three venous blood samples. Three samples: T0, T1, and T2. The ABBOTT-SARS-CoV-2 IgG II Quant and Elecsys® Anti-SARS-CoV-2 assays were used to evaluate the samples and convert the antibody titers to WHO (BAU)/mL units. Cancer patients exhibited a higher seroconversion rate at T2, regardless of vaccination type, and the mean antibody titers at T1 and T2 were higher than those at T0. BBIBP-CorV patients required a booster because BNT162b2 showed a higher seroconversion rate between T0 and T1. Statistics indicate that comparing Abbott and Roche quantitative antibody results without considering the sample collection time is inaccurate. COVID-19 vaccines can still induce a humoral immune response in patients undergoing cancer-targeted therapy. The strength of this study is the long-term monitoring of antibody levels after vaccination in cancer patients on active therapy using two different immunoassays. Further multicenter studies with a larger number of patients are required to validate these findings.

Literacy and Attitudes Towards COVID-19 Vaccine in Cancer Patients

Abstract Background Identifying motives of the patients’ decision to be vaccinated against COVID-19 and assessing their attitudes towards the vaccine will provide them acquire the most convenient health care. The aim of this study is to assess the cancer patients’ COVID-19 vaccine literacy and attitudes toward the vaccine. Methods This cross-sectional study included 198 participants who were submitted treatment from the oncology department of Pendik Training and Research Hospital in October 2022. The socio-demographic and clinical characteristics were examined, including the knowledge on COVID-19 infection and vaccination. COVID-19 Vaccine Literacy Scale and Attitudes Towards COVID-19 Vaccine Scale were evaluated. Mann Whitney U and Kruskal Wallis tests are used in SPSS 28. The statistical significance was set at 0.05 level. Results All of the patients had at least one malignancy history, and 88.4% (n = 175) of them had received at least one COVID-19 vaccine. Positive vaccination attitude was higher in those patients who are male (p < 0.05) or older than 60 years (p < 0.001). The vaccine literacy was higher in the male patients, those who had higher education, and those who had vaccination intention (p < 0.05, p < 0.05, p < 0.05). The ones who get influenza or pneumococcal vaccines were more likely to have the next COVID-19 vaccine (p < 0.05, p < 0.05). The male patients had higher scores in functional skills (p < 0.05). While functional skill scores were lowest in those aged 18 to 45 (p < 0.05), communication skill scores were highest (p < 0.05). Conclusions As with all infectious diseases, COVID-19 is an important public health concern. Identifying risk groups of the community based on the vaccine attitude would allow health practitioners and policymakers to be prepared for probable crisis situations such as pandemic. Key messages • Special groups such as cancer patients are needed to be specifically assessed about the possible outcomes of the vaccination. • It is essential to provide vaccination consultation during pandemics due to the limited availability and accessibility of healthcare services.

Complaisance of COVID-19 vaccination in cancer patients: A North Indian Tertiary Cancer Center (TCC) annotation

Complaisance of COVID-19 vaccination in cancer patients: A North Indian Tertiary Cancer Center (TCC) annotation

COVID-19 Infection despite Previous Vaccination in Cancer Patients and Healthcare Workers: Results from a French Prospective Multicenter Cohort (PAPESCO-19).

In a multicenter prospective cohort of cancer patients (CP; n = 840) and healthcare workers (HCWs; n = 935) vaccinated against COVID-19, we noticed the following: i/after vaccination, 4.4% of HCWs and 5.8% of CP were infected; ii/no characteristic was associated with post-vaccine COVID-19 infections among HCWs; iii/CP who developed infections were younger, more frequently women (NS), more frequently had gastrointestinal, gynecological, or breast cancer and a localized cancer stage; iv/CP vaccinated while receiving chemotherapy or targeted therapy had (NS) more breakthrough infections after vaccination than those vaccinated after these treatments; the opposite was noted with radiotherapy, immunotherapy, or hormonotherapy; v/most COVID-19 infections occurred either during the Alpha wave (11/41 HCW, 20/49 CP), early after the first vaccination campaign started, or during the Omicron wave (21/41 HCW, 20/49 CP), more than 3 months after the second dose; vi/risk of infection was not associated with values of antibody titers; vii/the outcome of these COVID-19 infections after vaccination was not severe in all cases. To conclude, around 5% of our CPs or HCWs developed a COVID-19 infection despite previous vaccination. The outcome of these infections was not severe.

SARS-CoV-2 Infection, Vaccination and Risk of Death in People with An Oncological Disease in Northeast Italy.

People with a history of cancer have a higher risk of death when infected with SARS-CoV-2. COVID-19 vaccines in cancer patients proved safe and effective, even if efficacy may be lower than in the general population. In this population-based study, we compare the risk of dying of cancer patients diagnosed with COVID-19 in 2021, vaccinated or non-vaccinated against SARS-CoV-2 and residing in Friuli Venezia Giulia or in the province of Reggio Emilia. An amount of 800 deaths occurred among 6583 patients; the risk of death was more than three times higher among unvaccinated compared to vaccinated ones [HR 3.4; 95% CI 2.9-4.1]. The excess risk of death was stronger in those aged 70-79 years [HR 4.6; 95% CI 3.2-6.8], in patients with diagnosis made <1 year [HR 8.5; 95% CI 7.3-10.5] and in all cancer sites, including hematological malignancies. The study results indicate that vaccination against SARS-CoV-2 infection is a necessary tool to be included in the complex of oncological therapies aimed at reducing the risk of death.

Covid Antibody Titers in Cancer Patients Following Vaccination with ChAdOx1 nCOV-19 Vaccine.

Dr. Vikram GotaCovid-19 has led to significant mortality worldwide, with an increased risk in cancer patients. Vaccination provides significant protection against the infection. The study focuses on the immunogenicity and effectiveness of ChAdOx1 nCoV-19 vaccine in cancer patients within a real-world setting. Blood samples for measuring Covid antibody titers against the receptor binding domain were collected according to a convenient sparse sampling strategy in a real-world setting, with the days of the collection coinciding with their hospital appointment. The antibody titers between different groups were analyzed descriptively. A total of 56 patients were enrolled in the study. There was no apparent effect in antibody titers between patients with solid tumors and hematological malignancies (mean ± standard deviation [SD]: 36.80 ± 41.18 vs. 52.02 ± 26.27), among patients who were undergoing chemotherapy, immunotherapy, or local therapy (mean ± SD: 42.50 ± 44.46 vs. 50.06 ± 51.39 vs. 28.70 ± 25.03), and in patients with up to 90 days and more than 90 days' interval between their last treatment and date of vaccination (mean ± SD: 38.96 ± 42.66 vs. 40.51 ± 38.65). Additionally, there were only 2/56 patients with breakthrough infection, which points out the effectiveness of this vaccine in cancer patients. The ChAdOx1 nCoV-19 vaccine has activity in cancer regardless of the tumor type, type of treatment, or time from the last treatment.

41 COVID-19 vaccination in cancer patients receiving chemotherapy: does vaccination increase the risk of hypersensitivity reactions?

41 COVID-19 vaccination in cancer patients receiving chemotherapy: does vaccination increase the risk of hypersensitivity reactions?

Immune-related adverse events and disease outcomes after the third dose of SARS-CoV-2 mRNA-BNT162b2 vaccine in cancer patients receiving immune checkpoint inhibitors.

The clinical implications of the third dose of coronavirus disease 2019 (COVID-19) vaccines in patients receiving immune checkpoint inhibitors are currently unknown. We performed a prospective analysis of the Vax-On-Third study to investigate the effects of antibody response on immune-related adverse events (irAEs) and disease outcomes. Recipients of the booster dose of SARS-CoV-2 mRNA-BNT162b2 vaccine who had received at least one course of an anti-PD-1/PD-L1 treatment before vaccination for an advanced solid malignancy were eligible. The current analysis included 56 patients with metastatic disease (median age: 66years; male: 71%), most of whom had a lung cancer diagnosis and were being treated with pembrolizumab- or nivolumab-based regimens. The optimal cut-point antibody titer of 486 BAU/mL allowed a dichotomization of recipients into low-responders (Low-R, < 486 BAU/mL) or high-responders (High-R, ≥ 486 BAU/mL). After a median follow-up time of 226days, 21.4% of patients experienced moderate to severe irAEs without any recrudescence of immune toxicities preceding the booster dose. The frequencies of irAE before and after the third dose did not differ, but an increase in the cumulative incidence of immuno-related thyroiditis was observed within the High-R subgroup. On multivariate analysis, an enhanced humoral response correlated with a better outcome in terms of durable clinical benefit, which resulted in a significant reduction in the risk of disease control loss but not mortality. Our findings would strengthen the recommendation not to change anti-PD-1/PD-L1 treatment plans based on current or future immunization schedules, implying that all these patients should be closely monitored.

Efficacy of the mRNA SARS-CoV-2 vaccine in cancer patients during systemic therapy. A single-centre experience

Efficacy of the mRNA SARS-CoV-2 vaccine in cancer patients during systemic therapy. A single-centre experience

Comparative Assessment of the Kinetics of Cellular and Humoral Immune Responses to COVID-19 Vaccination in Cancer Patients.

The kinetics of immune responses to various SARS-CoV-2 vaccines in cancer patients were investigated. In total, 57 cancer patients who received BNT162b2-RNA or BBIBP-CorV vaccines were enrolled. Cellular and humoral immunity were assessed at three-time points, before the first vaccine dose and 14-21 days after the first and second doses. Chemiluminescent microparticle immunoassay was used to evaluate SARS-CoV-2 anti-spike IgG response, and QuantiFERON® SARS-CoV-2 kit assessed T-cell response. Data showed that cancer patients' CD4+ and CD8+ T cell-median IFN-γ secretion of SARS-CoV-2 antigens increased after the first and second vaccine doses (p = 0.027 and p = 0.042). BNT162b2 vaccinees had significantly higher IFN-γ levels to CD4+ and CD8+ T cell epitopes than BBIBP-CorV vaccinees (p = 0.028). There was a positive correlation between IgG antibody titer and T cell response regardless of vaccine type (p < 0.05). This study is one of the first to investigate cellular and humoral immune responses to SARS-CoV-2 immunization in cancer patients on active therapy after each vaccine dose. COVID-19 immunizations helped cancer patients develop an effective immune response. Understanding the cellular and humoral immune response to COVID-19 in cancer patients undergoing active treatment is necessary to improve vaccines and avoid future SARS pandemics.

Longitudinal data on humoral response and neutralizing antibodies against SARS-CoV-2 Omicron BA.1 and subvariants BA.4/5 and BQ.1.1 after COVID-19 vaccination in cancer patients

PurposeThe SARS-CoV-2 Omicron variant of concern (VOC) and subvariants like BQ.1.1 demonstrate immune evasive potential. Little is known about the efficacy of booster vaccinations regarding this VOC and subvariants in cancer patients. This study is among the first to provide data on neutralizing antibodies (nAb) against BQ.1.1.MethodsCancer patients at our center were prospectively enrolled between 01/2021 and 02/2022. Medical data and blood samples were collected at enrollment and before and after every SARS-CoV-2 vaccination, at 3 and 6 months.ResultsWe analyzed 408 samples from 148 patients (41% female), mainly with solid tumors (85%) on active therapy (92%; 80% chemotherapy). SARS-CoV-2 IgG and nAb titers decreased over time, however, significantly increased following third vaccination (p < 0.0001). NAb (ND50) against Omicron BA.1 was minimal prior and increased significantly after the third vaccination (p < 0.0001). ND50 titers against BQ.1.1 after the third vaccination were significantly lower than against BA.1 and BA.4/5 (p < 0.0001) and undetectable in half of the patients (48%). Factors associated with impaired immune response were hematologic malignancies, B cell depleting therapy and higher age. Choice of vaccine, sex and treatment with chemo-/immunotherapy did not influence antibody response. Patients with breakthrough infections had significantly lower nAb titers after both 6 months (p < 0.001) and the third vaccination (p = 0.018).ConclusionWe present the first data on nAb against BQ.1.1 following the third vaccination in cancer patients. Our results highlight the threat that new emerging SARS-CoV-2 variants pose to cancer patients and support efforts to apply repeated vaccines. Since a considerable number of patients did not display an adequate immune response, continuing to exhibit caution remains reasonable.

COVID-19 and prevalence of venous thromboembolism among cancer patients: A nationwide inpatient sample analysis.

e18839 Background: Cancer, as well as immunosuppression from chemotherapy, aggravates thromboembolism risk. The risk is likely amplified in an additive fashion with COVID-19 infection, which confers a higher risk of VTE risk with viral sepsis, endothelial inflammation, and microthrombi formation. Numerous studies have shown the heightened risk of pulmonary embolism among severe COVID-19 patients. We sought to evaluate further the extent of COVID-19-associated coagulopathy and associated outcomes. Methods: National Inpatient Sample 2020 was used to identify non-elective hospitalizations of patients with a secondary diagnosis of any cancer. These were stratified into two cohorts based on the presence of the primary diagnosis of COVID-19. Primary outcomes include venous thromboembolism, PE, and VTE without PE in cancer patients with and without Covid-19 infection. The secondary outcomes examined were in-patient mortality, the average length of stay (LOS), and total hospital charge (THC). Multivariate analysis was performed to obtain the odds ratio. All weighted analysis was conducted through STATA 17. Results: Out of 1,734,735 non-elective admissions of patients with cancer, 36,295 (2%) were admitted for COVID-19. Our analysis showed statistically non-significant increased odds of venous thromboembolism(aOR:1.09 CI 0.99-1.20) in cancer patients with COVID. There was, however, a significant increase in the odds of pulmonary embolism(aOR 1.7, CI: 1.51- 1.91) among cancer patients with Covid-19. There were decreased odds of VTE without PE(aOR: 0.67 CI: 0.57-0.78). There was a statistically significant increase in odds of mortality (aOR: 2.8 CI: 2.63-3.0), length of stay(aOR:1.85 CI: 1.65- 2.05), total hospital charges($83,201 vs. $78,869 p: &lt; 0.01) in cancer patients with COVID-19 compared to cancer patients without COVID-19. Conclusions: This study shows that COVID-19 in cancer patients has deleterious effects, including an increased risk of pulmonary embolism and poor in-hospital outcomes. The finding of a lower incidence of non-PE VTE in patients with cancer is likely related to limitations with coding in NIS, in which lower complexity codes might be omitted in patients with multiple diagnoses. With significantly increased mortality and economic burden, these findings emphasize the significance of thrombotic prophylaxis and vaccination in cancer patients. [Table: see text]

Comparison of immunogenicity for Sinovac-CoronaVac vaccine vs. natural infection during cancer treatment.

Efficacy of the COVID-19 vaccines in cancer patients, especially during their active treatment, are lacking. Most of the studies in the literature compared the immunity in cancer patients with a cross-sectional cohort or retrospectively. Our study investigated Sinovac-CoronaVac COVID-19 vaccine immunogenicity and compared it with natural COVID-19 disease in cancer patients during their cancer therapy. A total of 111 patients with cancer and who are on active treatment were included in the study. This is a single-center study and was designed prospectively. Two group of patients were included in the study, natural disease and vaccinated group. A total of 111 patients were included in the study, 34 of whom had natural COVID-19 disease. Antibody levels following the first dose vaccine were 0.4 (0-1.9) U/ml while after the second dose of vaccine were 2.6 (1.0-7.25) U/ml. Immunogenicity levels were 82.4% in the natural disease group and 75.8% in the vaccinated group after the second shot of the vaccine. Immunogenicity rate was significantly higher in non-chemotherapy (receiving immunotehrapy/targeted therapy or biologic agent) group compared to chemotherapy drug (92.9% vs. 63.3%, p=0.004). There was a difference between the antibody levels following the first and second vaccination [median (IQR): 0.3 (0-1.0) and 3.3 (2.0-6.7), p=0.001, respectively]. The present study revealed that the Sinovac-CoronaVac vaccine showed an acceptable immunogenicity following two shots in cancer patients who were receiving active systemic therapy. On the other hand, natural disease immunogenicity was higher than vaccinated group.

OC-0910 Immunogenicity after two/three doses of mRNA vaccine in cancer patients treated with radiotherapy

OC-0910 Immunogenicity after two/three doses of mRNA vaccine in cancer patients treated with radiotherapy