Effects of Antibody Response after Booster Vaccination on SARS-CoV-2 Breakthrough Infections and Disease Outcomes in Advanced Cancer Patients: A Prospective Analysis of the Vax-on-Third Study.

(1) Background: The clinical implications of COVID-19 outbreaks following SARS-CoV-2 vaccination in immunocompromised recipients are a worldwide concern. Cancer patients on active treatment remain at an increased risk of developing breakthrough infections because of waning immunity and the emergence of SARS-CoV-2 variants. There is a paucity of data on the effects of COVID-19 outbreaks on long-term survival outcomes in this population. (2) Methods: We enrolled 230 cancer patients who were on active treatment for advanced disease and had received booster dosing of an mRNA-BNT162b2 vaccine as part of the Vax-On-Third trial between September 2021 and October 2021. Four weeks after the third immunization, IgG antibodies against the spike receptor domain of SARS-CoV-2 were tested in all patients. We prospectively evaluated the incidence of breakthrough infections and disease outcomes. The coprimary endpoints were the effects of antibody titers on the development of breakthrough infections and the impact of COVID-19 outbreaks on cancer treatment failure. (3) Results: At a median follow-up of 16.3 months (95% CI 14.5-17.0), 85 (37%) patients developed SARS-CoV-2 infection. Hospitalization was required in 11 patients (12.9%) and only 2 (2.3%) deaths related to COVID-19 outbreaks were observed. Median antibody titers were significantly lower in breakthrough cases than in non-cases (291 BAU/mL (95% CI 210-505) vs. 2798 BAU/mL (95% CI 2323-3613), p < 0.001). A serological titer cut-off below 803 BAU/mL was predictive of breakthrough infection. In multivariate testing, antibody titers and cytotoxic chemotherapy were independently associated with an increased risk of outbreaks. Time-to-treatment failure after booster dosing was significantly shorter in patients who contracted SARS-CoV-2 infection (3.1 months (95% CI 2.3-3.6) vs. 16.2 months (95% CI 14.3-17.0), p < 0.001) and had an antibody level below the cut-off (3.6 months (95% CI 3.0-4.5) vs. 14.6 months (95% CI 11.9-16.3), p < 0.001). A multivariate Cox regression model confirmed that both covariates independently had a worsening effect on time-to-treatment failure. (4) Conclusions: These data support the role of vaccine boosters in preventing the incidence and severity of COVID-19 outbreaks. Enhanced humoral immunity after the third vaccination significantly correlates with protection against breakthrough infections. Strategies aimed at restraining SARS-CoV-2 transmission in advanced cancer patients undergoing active treatment should be prioritized to mitigate the impact on disease outcomes.

The Impact of the Early COVID-19 Global Pandemic on Children Undergoing Active Cancer Treatment and Their Parents.

(1) Background: The COVID-19 global pandemic has impacted people worldwide with unique implications for vulnerable groups. In this cross-sectional study, we examined the impact of the early pandemic on children undergoing active cancer treatment and their parents. (2) Methods: In May 2020, 30 parents of children undergoing active cancer treatment completed an online survey regarding the impact of COVID-19 on their child's cancer care, perceived utility of telemedicine, and child and parent mental health status. (3) Results: Most participants (87%) reported that they did not experience any changes to major cancer treatments. Among those who reported using telemedicine, 78% reported this to be beneficial. Over half of the participants reported that their child's mental health status was worse now than prior to the COVID-19 global pandemic. Parent-reported child anxiety scores were significantly higher for those who reported changes to mental health care for their child compared to those who did not report the same, t(25.99) = -3.04, p = 0.005. (4) Conclusion: Child and parent mental health status were affected when compared to pre-pandemic. Telemedicine appears to be a promising complement to face-to-face meetings for some families and warrants further exploration.

Incidence of COVID-19 in outpatients with cancer receiving active treatment in the context of a pandemic: An Andalusian cohort study.

BACKGROUND: Leading scientific societies have recommended delaying and/or suspending active cancer treatment during the COVID-19 pandemic. Nevertheless, data on this novel infection in patients with a diagnosis of cancer receiving active treatment are scarce and it is unknown if these recommendations could have repercussions on future progress of the disease. The main objective of this study is to learn the COVID-19 incidence rate in outpatients with cancer receiving active treatment. METHODS: This work is a retrospective cohort study that included all patients with a diagnosis of cancer who received active cancer treatment in two Andalusian hospitals between February 26 and May 13, 2020. Variables regarding the patient, tumor, and development of COVID-19 were collected. A descriptive analysis was performed and the cumulative incidence of COVID-19 in these patients was evaluated. RESULTS: A total of 673 patients were included. The median age was 62 years. There was a low rate of comorbidity and 12.1% had an ECOG >2. Breast cancer was the most common cancer (41%), followed by colorectal and lung cancer. Stage IV cancer was reported in 52.7% of patients. The most common treatment was chemotherapy (53.9%). Treatment was delayed or suspended in 6% of patients. Only three patients developed COVID-19. The cumulative incidence was 0.44% and one person died due to infection. CONCLUSIONS: In the present retrospective cohort study we found a low incidence of COVID-19 infection in patients with cancer receiving active treatment in an outpatient setting. The sociodemographic factors of Andalusia may explain why these results differ from those presented by other colleagues in Spain, but raise questions about whether universal recommendations may put the benefits of antineoplastic therapy at risk.