The Predictive Value of Gut Microbiota Composition for Sustained Immunogenicity following Two Doses of CoronaVac.

CoronaVac immunogenicity decreases with time, and we aimed to investigate whether gut microbiota associate with longer-term immunogenicity of CoronaVac. This was a prospective cohort study recruiting two-dose CoronaVac recipients from three centres in Hong Kong. We collected blood samples at baseline and day 180 after the first dose and used chemiluminescence immunoassay to test for neutralizing antibodies (NAbs) against the receptor-binding domain (RBD) of wild-type SARS-CoV-2 virus. We performed shotgun metagenomic sequencing performed on baseline stool samples. The primary outcome was the NAb seroconversion rate (seropositivity defined as NAb ≥ 15AU/mL) at day 180. Linear discriminant analysis [LDA] effect size analysis was used to identify putative bacterial species and metabolic pathways. A univariate logistic regression model was used to derive the odds ratio (OR) of seropositivity with bacterial species. Of 119 CoronaVac recipients (median age: 53.4 years [IQR: 47.8-61.3]; male: 39 [32.8%]), only 8 (6.7%) remained seropositive at 6 months after vaccination. Bacteroides uniformis (log10LDA score = 4.39) and Bacteroides eggerthii (log10LDA score = 3.89) were significantly enriched in seropositive than seronegative participants. Seropositivity was associated with B. eggerthii (OR: 5.73; 95% CI: 1.32-29.55; p = 0.022) and B. uniformis with borderline significance (OR: 3.27; 95% CI: 0.73-14.72; p = 0.110). Additionally, B. uniformis was positively correlated with most enriched metabolic pathways in seropositive vaccinees, including the superpathway of adenosine nucleotide de novo biosynthesis I (log10LDA score = 2.88) and II (log10LDA score = 2.91), as well as pathways related to vitamin B biosynthesis, all of which are known to promote immune functions. In conclusion, certain gut bacterial species (B. eggerthii and B. uniformis) and metabolic pathways were associated with longer-term CoronaVac immunogenicity.

Association between Recent Usage of Antibiotics and Immunogenicity within Six Months after COVID-19 Vaccination.

Background: Gut microbiota can be associated with COVID-19 vaccine immunogenicity. We investigated whether recent antibiotic use influences BNT162b2 vaccine immunogenicity. Methods: BNT162b2 recipients from three centers were prospectively recruited. Outcomes of interest were seroconversion of neutralising antibody (NAb) at day 21, 56 and 180 after first dose. We calculated the adjusted odds ratio (aOR) of seroconversion with antibiotic usage (defined as ever use of any antibiotics within six months before first dose of vaccine) by adjusting for covariates including age, sex, smoking, alcohol, and comorbidities. Results: Of 316 BNT162b2 recipients (100 [31.6%] male; median age: 50.1 [IQR: 40.0-57.0] years) recruited, 29 (9.2%) were antibiotic users. There was a trend of lower seroconversion rates in antibiotic users than non-users at day 21 (82.8% vs. 91.3%; p = 0.14) and day 56 (96.6% vs. 99.3%; p = 0.15), but not at day 180 (93.3% vs. 94.1%). A multivariate analysis showed that recent antibiotic usage was associated with a lower seroconversion rate at day 21 (aOR 0.26;95% CI: 0.08-0.96). Other factors associated with a lower seroconversion rate after first dose of the BNT162b2 vaccine included age ≥ 60 years (aOR: 0.34;95% CI: 0.13-0.95) and male sex (aOR: 0.14, 95% CI: 0.05-0.34). There were no significant factors associated with seroconversion after two doses of BNT16b2, including antibiotic use (aOR: 0.03;95% CI: 0.001-1.15). Conclusions: Recent antibiotic use may be associated with a lower seroconversion rate at day 21 (but not day 56 or 180) among BNT162b2 recipients. Further long-term follow-up data with a larger sample size is needed to reach a definite conclusion on how antibiotics influence immunogenicity and the durability of the vaccine response.

Supportive care and symptom management in patients with advanced hematological malignancies: a literature review.

BACKGROUND AND OBJECTIVE: Recent advances have led to cure or long-term disease control for patients with hematological malignancy (HM). Unfortunately, some of them still have poor prognoses and are often associated with significant symptom burden and poor quality of life for patients and families. These patients usually require supportive care including red blood cell and platelet transfusion, due to disease itself and the oncological treatment, apart from their symptom management. However, there is currently lack of the literatures review in these aspects. The objective of this review is to summarize practical supportive care recommendations for physicians or nurses practicing in palliative care (PC)/hematology-oncology unit, starting with core approaches in use of blood products for anemia and thrombocytopenia, management of tumor lysis syndrome, PC and oncology nursing care. METHODS: Evidence for this review was obtained from a search of the Cochrane database, PubMed, guidelines of European Society of Medical Oncology, British society of Hematology, American Society of Clinical Oncology, National Comprehensive Cancer Network and peer-reviewed journal articles. KEY CONTENT AND FINDINGS: For asymptomatic cancer patients who are anaemic, a threshold of haemoglobin level of 7 g/dL is considered to be safe and generally favored for blood transfusion. 'Single-unit' red cell transfusion is safer and at least as effective as 'double-unit' transfusion. Prophylactic platelet transfusion should be given to stable patients without bleeding and with platelet count less than 10×109/L. In febrile patients, the threshold is lifted to 20×109/L. There are also recommendations for the use of blood products during COVID-19 pandemic. In general, HM patients were more prone to painful infections when compared with solid cancer patients. Thus, antibiotics to treat underlying infections should be applied whenever possible and as required to control pain. CONCLUSIONS: This narrative review showed the recent literatures in the supportive care and symptom management of advanced HM patients. However, it is limited by some of the 'evidence-based' recommendations for interventions (including symptom management) based on early phase of HM populations rather than those receiving end-of-life care.

Early integrated palliative care for haematology cancer patients-the impact on symptom burden in Hong Kong.

BACKGROUND: Evidence showed that early palliative care could have many benefits in clinical outcomes for patients living with advanced medical illnesses. In fact, most of these studies have not involved patients with advanced haematologic cancer (HC), which are known to be associated with significant physical and psychological symptoms. In Hong Kong, an Early Integrated Palliative Care (EIPC) collaboration involving both Heamatology unit of Queen Mary Hospital (QMH) and the Palliative Medical Unit of Grantham Hospital (GH) has been started since early 2018 as a better way to improve the service gap. The HC patients failed 2 or more lines of cancer treatment are identified during the joint round and hematology clinic. Some of these patients will be referred to our PC services. Our joint PC clinic has multidisciplinary input from palliative care physicians, hematologists, and clinical psychologists. The clinic program is well coordinated and structured. The HC patients are initially seen by the parent team for disease treatment and then by GH PC team for symptom control and psychosocial care. METHODS: This was a retrospective study with a review of the clinical charts and electronic healthcare records of all patients who attended the Hematology PC clinic from June 2018 to September 2020. For the inclusion criteria, patients were found eligible if they had prospectively completed Edmonton Symptom Assessment Scale (ESAS) assessments for at least the initial and follow-up visits within a range of ≥7 days and ≤60 days of the first visit. RESULTS: Thirty-eight patients ultimately agreed to the referral. The mean age was 70.5 (12.5) years old. Twenty-five patients (66%) had myelodysplastic syndrome (MDS); 10 (26%) had acute myeloid leukemia (AML). Around 50-60% of patients reported significant symptoms of fatigue, anxiety, drowsiness, and anorexia; 42% of patients had significantly depressed moods while 37% had pain. There were significant symptom improvements for pain, depression, and anxiety after follow-up visits. CONCLUSIONS: The study showed that our EIPC program resulted in a significant reduction in some of the important symptom item scores, including pain, anorexia, anxiety, and depression, after the follow-up visits.

Territory-Wide Study on Hospital Admissions for Asthma Exacerbations in the COVID-19 Pandemic.

Rationale: Patients with asthma were advised to avoid coronavirus disease (COVID-19) and comply with medication during the COVID-19 pandemic. Respiratory tract infection is a common cause of asthma exacerbations. There has not been evidence suggesting the link between COVID-19 and asthma exacerbation, especially in places with dramatic responses in infection control with universal masking and aggressive social distancing. Objectives: To assess the number for admissions of asthma exacerbations in January to April 2020 in Hong Kong with reference to admission in the past 5 years. Methods: Admission records of asthma exacerbations were retrieved from the Clinical Data Analysis and Reporting System. Patients aged 18 years or older with a known history of asthma admitted for asthma exacerbation were included. Log-linear was used to model count, with year and masking used as covariate and further analysis on ambient temperature and length of hospital stays. Fisher's exact test was used to compare the mortality rate and mechanical ventilation between the periods. Admissions for myocardial infarction, ischemic stroke, and gastric ulcer were included as controls. Results: The number of admissions for asthma exacerbations significantly decreased by 53.2% (95% confidence interval [CI], 50.4-55.8%) in 2020 compared with monthly average admission in 2015-2019, with a higher magnitude of decrease compared with control diagnoses. Admissions for asthma exacerbations decreased by 2.0% (95% CI, 1.8-2.2%) with every 1°C (1.8°F) increase in temperature and by 0.8% with every 1% increase in masking (95% CI, 0.8-0.9%). Conclusions: Hospitalization number for asthma exacerbations significantly decreased in early 2020, with similar length of stay. This was observed with concomitant practice of universal masking and social distancing during the COVID-19 pandemic in Hong Kong. We proposed that universal masking and social distancing reduced respiratory viral infection, leading to fewer hospital admissions for asthma exacerbations.