Corowa-kun: A messenger app chatbot delivers COVID-19 vaccine information, Japan 2021.

BACKGROUND: There is a long history in Japan of public concerns about vaccine adverse events. Few studies have assessed how mobile messenger apps affect COVID-19 vaccine hesitancy. METHODS: Corowa-kun, a free chatbot, was created on February 6, 2021 in LINE, the most popular messenger app in Japan. Corowa-kun provides instant, automated answers to 70 frequently asked COVID-19 vaccine questions. A cross-sectional survey with 21 questions was performed within Corowa-kun during April 5-12, 2021. RESULTS: A total of 59,676 persons used Corowa-kun during February-April 2021. Of them, 10,192 users (17%) participated in the survey. Median age was 55 years (range 16-97), and most were female (74%). COVID-19 vaccine hesitancy reported by survey respondents decreased from 41% to 20% after using Corowa-kun. Of the 20% who remained hesitant, 16% (1,675) were unsure, and 4% (364) did not intend to be vaccinated. Factors associated with vaccine hesitancy were: age 16-34 (odds ratio [OR] = 3.7; 95% confidential interval [CI]: 3.0-4.6, compared to age ≥ 65), female sex (OR = 2.4; Cl: 2.1-2.8), and history of a previous vaccine side-effect (OR = 2.5; Cl: 2.2-2.9). Being a physician (OR = 0.2; Cl: 0.1-0.4) and having received a flu vaccine the prior season (OR = 0.4; Cl: 0.3-0.4) were protective. CONCLUSIONS: A substantial number of people used the chabot in a short period. Mobile messenger apps could be leveraged to provide accurate vaccine information and to investigate vaccine intention and risk factors for vaccine hesitancy.

Febrile neutropenia in a patient with non-small-cell lung cancer treated with atezolizumab: A case report.

Hematological immune-related adverse events (hem-irAEs) related to immunotherapy have not been extensively characterized, and there is no report of neutropenia caused by atezolizumab administration. Herein, we report a case of febrile neutropenia caused by a hem-irAEs due to atezolizumab, which was treated with granulocyte-colony stimulating factor (G-CSF) and antibiotic prophylaxis. It is important that oncologists be aware of the hematological toxicities of immune checkpoint inhibitors (ICIs). Furthermore, antibiotics and G-CSF should be administered until absolute neutrophil count recovery in cases of febrile neutropenia complicated by atezolizumab. Systemic corticosteroids should not be administered because they can accentuate the risk of infection.