ABSTRACT
Inferring group membership of social media users is of high interest in many domains. Group membership is typically inferred via network interactions with other members, or by the usage of in-group language. However, network information is incomplete when users or groups move between platforms, and in-group keywords lose significance as public discussion about a group increases. Similarly, using keywords to filter content and users can fail to distinguish between the various groups that discuss a topic-perhaps confounding research on public opinion and narrative trends. We present a classifier intended to distinguish members of groups from users discussing a group based on contextual usage of keywords. We demonstrate the classifier on a sample of community pairs from Reddit and focus on results related to the COVID-19 pandemic.
ABSTRACT
Background: Concerns about safety and treatment interference are known barriers to COVID-19 vaccination in cancer patients. Data on safety and tolerability in this population remain scarce. One of the objectives of this study is to describe COVID-19 vaccination safety in cancer patients. Methods: Patients diagnosed with a malignancy requiring systemic treatment in the last 12 months and undergoing COVID-19 vaccination were prospectively enrolled in this single-center study. Validated questionnaires to assess vaccine-related adverse events (VRAEs) were collected;chart review identified baseline characteristics and treatments received. Descriptive statistics and logistic regressions were performed. Results: 253 questionnaires were collected from 171 patients, enrolled between May and September 2021. 130 patients were survey-eligible after the 1st dose (D1) and 185 after 2nd dose (D2). 91 questionnaires were collected after D1 (Questionnaire 1: Q1) and 162 after D2 (Questionnaire 2: Q2). Surveys couldn't be collected due to interval > 1 month between D1 / enrollment, patients' unavailability, withdrawal of study or death. Median age was 55 (24-87) and 62.8% were female. 58.5% had solid tumors, treated with chemotherapy (49%) or checkpoint inhibitors only (9.5%);19.4% malignancies were treated with targeted therapies and 22.1% had hematological malignancies. Most frequent solid tumors were breast (31.3%), lung (15.9%) and gastro-intestinal (GI) (14.3%). Patients received 45.6% Pfizer/BioNTech, 52.8% Moderna and 1.6% Oxford/AstraZeneca. A combination of 2 different vaccines was administered to 11.9%. Interval between D1 and D2 was ≤30 days in 53.1%, 31-90 days in 42.6%, and 91-180 days in 4.3%. Among all patients, 84.1% developed VRAEs after a median of 2 days post-vaccine for a median of 4 days. 74.5% had local symptoms (Sx) (pain, sensitivity and/or redness at injection site and/or arm) and 65.8% had systemic Sx. Most frequent systemic Sx were fatigue, chills or myalgia (39.4%), GI (6.3%) and fever (2.9%). Most patients (90.7%) described their Sx as having no / minimal impact (Gr 1), 7.8% reported seeking medical consultation (Gr 2), and 1.5% lead to hospitalization (Gr 3) (1 cardiovascular event, 1 infection;causality with concurrent systemic treatment not excluded and 1 due to malignancy). Gr 2, but not Gr 3, VRAEs were more common after D2 (11.4% vs 2.5%, p = 0.03). 41.7% considered their Sx as a new health problem. On multivariate analysis, younger age and female sex were significantly associated with the development of any Sx (OR 1.08, p = 0.01;OR 2.92, p = 0.02, respectively) and local Sx (OR 1.04, p = 0.04;OR 2.19, p = 0.04), but not systemic Sx or new health problem. Conclusions: Patients experienced mostly minor and transient symptoms post-vaccination;few perceived these as a new health problem. COVID-19 vaccination is overall safe and well-tolerated among cancer patients.