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.

Effects of sequential vs single pneumococcal vaccination on cardiovascular diseases among older adults: a population-based cohort study.

BACKGROUND: Recommendations around the use of 23-valent pneumococcal polysaccharide vaccine (PPSV23) and 13-valent pneumococcal conjugate vaccine (PCV13) seldom focus on potential benefits of vaccine on comorbidities. We aimed to investigate whether sequential vaccination with PCV13 and PPSV23 among older adults would provide protection against cardiovascular diseases (CVD) compared with using a single pneumococcal vaccine. METHODS: We conducted a Hong Kong-wide retrospective cohort study between 2012 and 2020. Adults aged ≥65 years were identified as receiving either a single or sequential dual vaccination and followed up until the earliest CVD occurrence, death or study end. To minimize confounding, we matched each person receiving a single vaccination to a person receiving sequential vaccination according to their propensity scores. We estimated the hazard ratio (HR) of CVD risk using Cox regression and applied structural equation modelling to test whether the effect of sequential dual vaccination on CVD was mediated via the reduction in pneumonia. RESULTS: After matching, 69 390 people remained in each group and the median (interquartile range) follow-up time was 1.89 (1.55) years. Compared with those receiving a single vaccine, those receiving sequential dual vaccination had a lower risk of CVD [HR (95% CI): 0.75 (0.71, 0.80), P < 0.001]. Post-hoc mediation analysis showed strong evidence that the decreased CVD risk was mediated by the reduction in all-cause pneumonia. CONCLUSIONS: Sequential dual pneumococcal vaccination was associated with lower risk of CVD compared with single-dose PCV13 or PPSV23 in older adults. Such additional CVD benefits should be considered when making decisions about pneumococcal vaccination.

Optimal timing of nirmatrelvir/ritonavir treatment after COVID-19 symptom onset or diagnosis: target trial emulation.

Reports of symptomatic rebound and/or test re-positivity among COVID-19 patients following the standard five-day treatment course of nirmatrelvir/ritonavir have sparked debates regarding optimal treatment timing and dosage. It is unclear whether initiating nirmatrelvir/ritonavir immediately after symptom onset would improve clinical outcomes and/or lead to post-treatment viral burden rebound due to inadequate viral clearance during treatment. Here we show that, by emulating a randomized target trial using real-world electronic medical record data from all 87,070 adult users of nirmatrelvir/ritonavir in Hong Kong between 16th March 2022 and 15th January 2023, early initiation of nirmatrelvir/ritonavir treatment (0 to 1 days after symptom onset or diagnosis) significantly reduced the incidence of 28-day all-cause mortality and hospitalization compared to delayed initiation (2 or more days) (absolute risk reduction [ARR]: 1.50% (95% confidence interval 1.17-1.80%); relative risk [RR]: 0.77 (0.73, 0.82)), but may be associated with a significant elevated risk of viral burden rebound (ARR: -1.08% (-1.55%, -0.46%)), although the latter estimates were associated with high uncertainty due to limited sample sizes. As such, patients should continue to initiate nirmatrelvir/ritonavir early after symptom onset or diagnosis to better protect against the more serious outcomes of hospitalization and mortality.

Antibiotic Use Prior to COVID-19 Vaccine Is Associated with Higher Risk of COVID-19 and Adverse Outcomes: A Propensity-Scored Matched Territory-Wide Cohort.

Background: Antibiotics may increase the risk of COVID-19 among non-vaccinated subjects via probable gut dysbiosis. We aimed to investigate whether antibiotics also affect the clinical outcomes of COVID-19 vaccine recipients. Methods: This was a territory-wide cohort study of 3,821,302 COVID-19 vaccine recipients (aged ≥ 18 years) with ≥2 doses of either BNT162b2 or CoronaVac. Exclusion criteria included prior COVID-19, prior gastrointestinal surgery, and immunocompromised status. The primary outcome was COVID-19 infection and secondary outcomes included COVID-19-related hospitalization and severe infection (composite of intensive care unit admission, ventilatory support, and/or death). Exposure was pre-vaccination antibiotic use (within 180 days of first vaccine dose). Covariates included age, sex, Charlson Comorbidity Index, and concomitant medication use. Subjects were followed from the index date (first dose vaccination) until outcome occurrence, death, an additional dose of vaccination, or 15 November 2022. Propensity score (PS) matching and a Poisson regression model were used to estimate the adjusted incidence rate ratio (aIRR) of outcomes with antibiotic use. Results: Among 342,338 PS matched three-dose vaccine recipients (mean age: 57.4 years; male: 45.1%) with a median follow-up of 13.6 months (IQR: 9.2-16.3), antibiotics were associated with a higher risk of COVID-19 infection (aIRR: 1.16;95% CI: 1.14-1.19), hospitalization (aIRR: 1.75;95% CI: 1.65-1.86), and severe infection (aIRR: 1.60; 95% CI: 1.21-2.11). Notably, antibiotic use was associated with a higher risk of severe infection and death among CoronaVac recipients (aIRR: 1.62 95% CI: 1.18-2.22 and aIRR: 2.70, 95% CI: 1.54-4.73 for the two secondary outcomes, respectively), but not BNT162b2 recipients. Conclusions: Pre-vaccination use of antibiotics was associated with a higher risk of COVID-19 infection, hospitalization, and severe disease outcomes.

Randomized Trial of Anticoagulation Strategies for Noncritically Ill Patients Hospitalized With COVID-19.

BACKGROUND: Prior studies of therapeutic-dose anticoagulation in patients with COVID-19 have reported conflicting results. OBJECTIVES: We sought to determine the safety and effectiveness of therapeutic-dose anticoagulation in noncritically ill patients with COVID-19. METHODS: Patients hospitalized with COVID-19 not requiring intensive care unit treatment were randomized to prophylactic-dose enoxaparin, therapeutic-dose enoxaparin, or therapeutic-dose apixaban. The primary outcome was the 30-day composite of all-cause mortality, requirement for intensive care unit-level of care, systemic thromboembolism, or ischemic stroke assessed in the combined therapeutic-dose groups compared with the prophylactic-dose group. RESULTS: Between August 26, 2020, and September 19, 2022, 3,398 noncritically ill patients hospitalized with COVID-19 were randomized to prophylactic-dose enoxaparin (n = 1,141), therapeutic-dose enoxaparin (n = 1,136), or therapeutic-dose apixaban (n = 1,121) at 76 centers in 10 countries. The 30-day primary outcome occurred in 13.2% of patients in the prophylactic-dose group and 11.3% of patients in the combined therapeutic-dose groups (HR: 0.85; 95% CI: 0.69-1.04; P = 0.11). All-cause mortality occurred in 7.0% of patients treated with prophylactic-dose enoxaparin and 4.9% of patients treated with therapeutic-dose anticoagulation (HR: 0.70; 95% CI: 0.52-0.93; P = 0.01), and intubation was required in 8.4% vs 6.4% of patients, respectively (HR: 0.75; 95% CI: 0.58-0.98; P = 0.03). Results were similar in the 2 therapeutic-dose groups, and major bleeding in all 3 groups was infrequent. CONCLUSIONS: Among noncritically ill patients hospitalized with COVID-19, the 30-day primary composite outcome was not significantly reduced with therapeutic-dose anticoagulation compared with prophylactic-dose anticoagulation. However, fewer patients who were treated with therapeutic-dose anticoagulation required intubation and fewer died (FREEDOM COVID [FREEDOM COVID Anticoagulation Strategy]; NCT04512079).

Effect of Moderate to Severe Hepatic Steatosis on Vaccine Immunogenicity against Wild-Type and Mutant Virus and COVID-19 Infection among BNT162b2 Recipients.

BACKGROUND: We aimed to investigate the effect of non-alcoholic fatty liver disease (NAFLD) on BNT162b2 immunogenicity against wild-type SARS-CoV-2 and variants and infection outcome, as data are lacking. METHODS: Recipients of two doses of BNT162b2 were prospectively recruited. Outcomes of interest were seroconversion of neutralizing antibody by live virus microneutralization (vMN) to SARS-CoV-2 strains (wild-type, delta and omicron variants) at day 21, 56 and 180 after first dose. Exposure of interest was moderate-to-severe NAFLD (controlled attenuation parameter ≥ 268 dB/M on transient elastography). We calculated adjusted odds ratio (aOR) of infection with NAFLD by adjusting for age, sex, overweight/obesity, diabetes and antibiotic use. RESULTS: Of 259 BNT162b2 recipients (90 (34.7%) male; median age: 50.8 years (IQR: 43.6-57.8)), 68 (26.3%) had NAFLD. For wild type, there was no difference in seroconversion rate between NAFLD and control groups at day 21 (72.1% vs. 77.0%; p = 0.42), day 56 (100% vs. 100%) and day 180 (100% and 97.2%; p = 0.22), respectively. For the delta variant, there was no difference also at day 21 (25.0% vs. 29.5%; p = 0.70), day 56 (100% vs. 98.4%; p = 0.57) and day 180 (89.5% vs. 93.3%; p = 0.58), respectively. For the omicron variant, none achieved seroconversion at day 21 and 180. At day 56, there was no difference in seroconversion rate (15.0% vs. 18.0%; p = 0.76). NAFLD was not an independent risk factor of infection (aOR: 1.50; 95% CI: 0.68-3.24). CONCLUSIONS: NAFLD patients receiving two doses of BNT162b2 had good immunogenicity to wild-type SARS-CoV-2 and the delta variant but not the omicron variant, and they were not at higher risk of infection compared with controls.

Viral burden rebound in hospitalised patients with COVID-19 receiving oral antivirals in Hong Kong: a population-wide retrospective cohort study.

BACKGROUND: Viral rebound after nirmatrelvir-ritonavir treatment has implications for the clinical management and isolation of patients with COVID-19. We evaluated an unselected, population-wide cohort to identify the incidence of viral burden rebound and associated risk factors and clinical outcomes. METHODS: We did a retrospective cohort study of hospitalised patients with a confirmed diagnosis of COVID-19 in Hong Kong, China, for an observation period from Feb 26 to July 3, 2022 (during the omicron BA.2.2 variant wave). Adult patients (age ≥18 years) admitted 3 days before or after a positive COVID-19 test were selected from medical records held by the Hospital Authority of Hong Kong. We included patients with non-oxygen-dependent COVID-19 at baseline receiving either molnupiravir (800 mg twice a day for 5 days), nirmatrelvir-ritonavir (nirmatrelvir 300 mg with ritonavir 100 mg twice a day for 5 days), or no oral antiviral treatment (control group). Viral burden rebound was defined as a reduction in cycle threshold (Ct) value (≥3) on quantitative RT-PCR test between two consecutive measurements, with such decrease sustained in an immediately subsequent Ct measurement (for those patients with ≥3 Ct measurements). Logistic regression models were used to identify prognostic factors for viral burden rebound, and to assess associations between viral burden rebound and a composite clinical outcome of mortality, intensive care unit admission, and invasive mechanical ventilation initiation, stratified by treatment group. FINDINGS: We included 4592 hospitalised patients with non-oxygen-dependent COVID-19 (1998 [43·5%] women and 2594 [56·5%] men). During the omicron BA.2.2 wave, viral burden rebound occurred in 16 of 242 patients (6·6% [95% CI 4·1-10·5]) receiving nirmatrelvir-ritonavir, 27 of 563 (4·8% [3·3-6·9]) receiving molnupiravir, and 170 of 3787 (4·5% [3·9-5·2]) in the control group. The incidence of viral burden rebound did not differ significantly across the three groups. Immunocompromised status was associated with increased odds of viral burden rebound, regardless of antiviral treatment (nirmatrelvir-ritonavir: odds ratio [OR] 7·37 [95% CI 2·56-21·26], p=0·0002; molnupiravir: 3·05 [1·28-7·25], p=0·012; control: 2·21 [1·50-3·27], p<0·0001). Among patients receiving nirmatrelvir-ritonavir, the odds of viral burden rebound were higher in those aged 18-65 years (vs >65 years; 3·09 [1·00-9·53], p=0·050), those with high comorbidity burden (score >6 on the Charlson Comorbidity Index; 6·02 [2·09-17·38], p=0·0009), and those concomitantly taking corticosteroids (7·51 [1·67-33·82], p=0·0086); whereas the odds were lower in those who were not fully vaccinated (0·16 [0·04-0·67], p=0·012). In patients receiving molnupiravir, those aged 18-65 years (2·68 [1·09-6·58], p=0·032) or on concomitant corticosteroids (3·11 [1·23-7·82], p=0·016) had increased odds of viral burden rebound. We found no association between viral burden rebound and occurrence of the composite clinical outcome from day 5 of follow-up (nirmatrelvir-ritonavir: adjusted OR 1·90 [0·48-7·59], p=0·36; molnupiravir: 1·05 [0·39-2·84], p=0·92; control: 1·27 [0·89-1·80], p=0·18). INTERPRETATION: Viral burden rebound rates are similar between patients with antiviral treatment and those without. Importantly, viral burden rebound was not associated with adverse clinical outcomes. FUNDING: Health and Medical Research Fund, Health Bureau, The Government of the Hong Kong Special Administrative Region, China. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Corrigendum: Co-stimulation with TLR7 agonist imiquimod and inactivated Influenza virus particles promotes mouse B cell activation, differentiation, and accelerated antigen specific antibody production.

[This corrects the article DOI: 10.3389/fimmu.2018.02370.].

Global Consumption Trend of Antifungal Agents in Humans From 2008 to 2018: Data From 65 Middle- and High-Income Countries.

BACKGROUND: Understanding the trend of global antifungal agent consumption could assist with identification of global healthcare policy inadequacies and promote accessibility and availability of antifungal agents. METHODS: Using pharmaceutical sales data from the IQVIA-multinational integrated data analysis system database, we assessed use of systemic antifungal agents in humans in 27 middle- and 38 high-income countries from 2008 through 2018. RESULTS: Consumption of systemic antifungal agents increased from 0.50 (in 2008) to 0.92 defined daily dose (DDD)/1000 inhabitants/day (in 2018), with a compound annual growth rate of 6.2%. High-income countries remain major consumers of antifungal agents with large variance in quantities consumed, with a gradual decline in consumption in recent years. Consumption in middle-income countries increased. Itraconazole (0.32 DDD/1000 inhabitants/day), terbinafine (0.30 DDD/1000 inhabitants/day), and fluconazole (0.23 DDD/1000 inhabitants/day) were the most commonly used antifungal agents in middle- and high-income countries in 2018. Following incorporation into the World Health Organization Essential Medicines List, itraconazole consumption in middle-income countries surged. Consumption of ketoconazole slowly declined, with 5.04% annual decrease, probably due to labelling changes in 2013 to reflect hepatotoxicity concerns. The use of polyenes (0.004 DDD/1000 inhabitants/day) and echinocandins (0.003 DDD/1000 inhabitants/day) were lowest among all the antifungal drug classes. CONCLUSION: Global consumption of triazoles and terbinafine has gradually increased in middle- and high-income countries. Life-saving antifungal agents, including echinocandins and polyenes, are available only parenterally and may be underutilized, mainly in middle-income countries. Future research on country-specific epidemiology is warranted to guide health policy coordination to ensure equitable access to appropriate use of antifungal agents.

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.

Association between antibiotic consumption and colon and rectal cancer development in older individuals: A territory-wide study.

BACKGROUND: Antibiotics may alter colorectal cancer (CRC) risk due to gut dysbiosis. We aimed to study the specific and temporal effects of various antibiotics on CRC development in older individuals. METHODS: This was a territory-wide retrospective cohort study. Subjects aged 60 years and older who did not have CRC diagnosed on screening/diagnostic colonoscopy diagnosed between 2005 and 2013 were recruited. Exclusion criteria were history of CRC, colectomy, inflammatory bowel disease, and CRC diagnosed within 6 months of index colonoscopy. Exposure was use of any antibiotics up to 5 years before colonoscopy. The primary outcomes were CRC diagnosed >6 m after colonoscopy. Covariates were patient demographics, history of colonic polyps/polypectomy, concomitant medication use (NSAIDs, COX-2 inhibitors, aspirin, and statins), and performance of endoscopy centers (colonoscopy volume and polypectomy rate). Stratified analysis was conducted according to nature of antibiotics and location of cancer. RESULTS: Ninety seven thousand one hundred and sixty-two eligible subjects (with 1026 [1.0%] cases of CRC) were identified, 58,704 (60.4%) of whom were exposed to antibiotics before index colonoscopy. Use of antibiotics was associated with a lower risk of cancer in rectum (adjusted hazard ratio [aHR]: 0.64, 95% CI: 0.54-0.76), but a higher risk of cancer in proximal colon (aHR: 1.63, 95%CI: 1.15-2.32). These effects differed as regards the anti-anaerobic/anti-aerobic activity, narrow-/broad-spectrum, and administration route of antibiotics. CONCLUSIONS: Antibiotics had divergent effects on CRC development in older subjects, which varied according to the location of cancer, antibiotic class, and administration route.

Diagnostic Value of a SARS-CoV-2 Rapid Test Kit for Detection of Neutralizing Antibodies as a Point-of-Care Surveillance Test.

Detection and tracking of antibodies play an increasingly prominent role in population surveillance and implementation of public health measures to combat the current coronavirus disease 2019 (COVID-19) pandemic, with much attention placed on developing commercial serological assays as point-of-care diagnostic tools. While many rapid diagnostic tests (RDTs) that detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG and IgM antibodies have been evaluated, there is currently limited insight into detection of neutralizing antibodies (nAbs) by such modalities. Here, we evaluate performance characteristics of an RDT that detects SARS-CoV-2 IgG antibodies and, importantly, nAbs based on both infection- and vaccine-immunized cohorts by direct comparison to known antibody titers obtained from live virus microneutralization (VMN) assays. We further contextualize interpretations of band intensity of the RDT with reference to the World Health Organization (WHO) International Standard. We report a sensitivity of 94.37% and specificity of 92.50% for SARS-CoV-2 IgG detection and a sensitivity of 94.37% and specificity of 92.68% for nAbs. A limit of detection was determined as 3.125 IU/mL and 25.00 IU/mL, respectively, with reference to the WHO International Standard. We confirm that indication of nAb concentration, as elucidated by band intensity on the RDT, correlated with nAb titers defined by VMN assays and surrogate nAb assays. We additionally observe no cross-reactivity of the nAb test line to SARS-CoV-1 but report display of weak seropositivity for one sample on the SARS-CoV-2 IgG test line. Our study reveals promising performance characteristics of the assessed RDT, which implicates its usefulness in a wide range of diagnostic and epidemiological settings. IMPORTANCE In the ongoing coronavirus disease 2019 (COVID-19) pandemic, antibody tests play an increasingly important role in detecting previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and monitoring of response to vaccinations. In particular, neutralizing antibodies have recently been demonstrated to be highly predictive of immune protection against symptomatic infection. Our study is the first to evaluate a rapid diagnostic test based on samples acquired from both recovered COVID-19 patients and individuals vaccinated for SARS-CoV-2, which detects neutralizing antibodies in addition to SARS-CoV-2 IgG. We report promising sensitivity, specificity, and cross-reactivity profiles, which implicate its usefulness in a wide range of settings as a diagnostic point-of-care tool to aid in curbing transmission and reducing mortality caused by COVID-19 symptoms.

A Sensitive and Specific Competitive Enzyme-Linked Immunosorbent Assay for Serodiagnosis of COVID-19 in Animals.

In addition to human cases, cases of COVID-19 in captive animals and pets are increasingly reported. This raises the concern for two-way COVID-19 transmission between humans and animals. Here, we developed a SARS-CoV-2 nucleocapsid protein-based competitive enzyme-linked immunosorbent assay (cELISA) for serodiagnosis of COVID-19 which can theoretically be used in virtually all kinds of animals. We used 187 serum samples from patients with/without COVID-19, laboratory animals immunized with inactive SARS-CoV-2 virions, COVID-19-negative animals, and animals seropositive to other betacoronaviruses. A cut-off percent inhibition value of 22.345% was determined and the analytical sensitivity and specificity were found to be 1:64-1:256 and 93.9%, respectively. Evaluation on its diagnostic performance using 155 serum samples from COVID-19-negative animals and COVID-19 human patients showed a diagnostic sensitivity and specificity of 80.8% and 100%, respectively. The cELISA can be incorporated into routine blood testing of farmed/captive animals for COVID-19 surveillance.

Comparative evaluation of a dual-target real-time RT-PCR assay for COVID-19 diagnosis and assessment of performance in pooled saliva and nasopharyngeal swab samples.

OBJECTIVES: Sensitive molecular diagnostic assays are essential for COVID-19 diagnosis. We evaluated the Hecin Scientific SARS-CoV-2 nucleic acid test kit, a dual-target real-time RT-PCR assay targeting the SARS-CoV-2 N and ORF1ab genes. METHODS: The Hecin test kit's diagnostic performance in detecting SARS-CoV-2 RNA was compared to the LightMix Modular SARS and Wuhan CoV E-gene kit (TIB Molbiol) and an in-house single-tube nested real-time RT-PCR using 296 clinical specimens, 11 proficiency testing samples, and 30 low-positive deep throat saliva and nasopharyngeal swab (NPS) samples pooled into negative samples in ratios of 1:5, 1:10, and 1:30. RESULTS: The limit-of-detection of the Hecin test kit was around 500 dC/mL for the N and ORF1ab targets. Sensitivity and specificity of the Hecin test kit were 98.1% (95% CI: 93.4-99.8%) and 100% (98.1-100%), respectively, when measured against the reference method. The Hecin test kit showed fair sensitivity (80%) in low-positive NPS samples pooled in ratios of 1:5 and 1:10. Its performance in pooled samples could be dramatically improved by adjusting the assay Ct cutoff. CONCLUSION: The Hecin test kit enables sensitive and specific detection of SARS-CoV-2 in clinical samples and pooled samples.

The impact of childhood pneumococcal conjugate vaccine immunisation on all-cause pneumonia admissions in Hong Kong: A 14-year population-based interrupted time series analysis.

BACKGROUND: Nine years after the introduction of pneumococcal conjugate vaccine (PCV) in the United States, Hong Kong (HK) introduced the vaccine to its universal childhood immunisation programme in 2009. We aimed to assess the impact of childhood PCV immunisation on all-cause pneumonia (ACP) admissions among the overall population of HK. METHODS: In this population-based interrupted time series analysis, we used territory-wide population-representative electronic health records in HK to evaluate the vaccine impact. We identified hospitalised patients with a diagnosis of pneumonia from any cause between 2004 and 2017. We applied segmented Poisson regression to assess the gradual change in the monthly incidence of ACP admissions between pre- and post-vaccination periods. Negative outcome control, subgroup and sensitivity analyses were used to test the robustness of the main analysis. FINDINGS: Over the 14-year study period, a total of 587,607 ACP episodes were identified among 357,950 patients. The monthly age-standardised incidence of ACP fluctuated between 33.42 and 87.44 per 100,000-persons. There was a marginal decreasing trend in pneumonia admissions after PCV introduction among overall population (incidence rate ratio [IRR]: 0·9965, 95% confidence interval [CI]: 0·9932-0·9998), and older adults (≥65 years, IRR: 0·9928, 95% CI: 0·9904-0·9953) but not in younger age groups. INTERPRETATION: There was a marginally declining trend of overall ACP admissions in HK up to eight years after childhood PCV introduction. The significance disappeared when fitting sensitivity analyses. The results indicate the complexities of using non-specific endpoints for measuring vaccine effect and the necessity of enhancing serotype surveillance systems for replacement monitoring. FUNDING: Health and Medical Research Fund, Food and Health Bureau of the Government of Hong Kong (Reference number: 18171272).

Systematic Review and Patient-Level Meta-Analysis of SARS-CoV-2 Viral Dynamics to Model Response to Antiviral Therapies.

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) viral loads change rapidly following symptom onset, so to assess antivirals it is important to understand the natural history and patient factors influencing this. We undertook an individual patient-level meta-analysis of SARS-CoV-2 viral dynamics in humans to describe viral dynamics and estimate the effects of antivirals used to date. This systematic review identified case reports, case series, and clinical trial data from publications between January 1, 2020, and May 31, 2020, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A multivariable Cox proportional hazards (Cox-PH) regression model of time to viral clearance was fitted to respiratory and stool samples. A simplified four parameter nonlinear mixed-effects (NLME) model was fitted to viral load trajectories in all sampling sites and covariate modeling of respiratory viral dynamics was performed to quantify time-dependent drug effects. Patient-level data from 645 individuals (age 1 month to 100 years) with 6,316 viral loads were extracted. Model-based simulations of viral load trajectories in samples from the upper and lower respiratory tract, stool, blood, urine, ocular secretions, and breast milk were generated. Cox-PH modeling showed longer time to viral clearance in older patients, men, and those with more severe disease. Remdesivir was associated with faster viral clearance (adjusted hazard ratio (AHR) = 9.19, P < 0.001), as well as interferon, particularly when combined with ribavirin (AHR = 2.2, P = 0.015; AHR = 6.04, P = 0.006). Combination therapy should be further investigated. A viral dynamic dataset and NLME model for designing and analyzing antiviral trials has been established.

Treatment of coronavirus disease 2019.

PURPOSE OF REVIEW: Coronavirus disease 2019 (COVID-19) is a highly contagious and potentially lethal pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). No specific antiviral treatment is currently available. The purpose of this review is to highlight the main repurposed drug treatments with in-vitro or in-vivo efficacy against the SARS-CoV-2. RECENT FINDINGS: Recent clinical trials suggested remdesivir, IFN-ß-1b and favipiravir have potential clinical and/or virological benefits on patients with COVID-19. Short course of stress dose of corticosteroids might be used as adjunctive treatment to patients who are late presenters with cytokine storm. Convalescent plasma from recovered COVID-19 patients with high neutralizing antibody might also be beneficial in the treatment of severe disease. SUMMARY: Early effective antiviral therapy in COVID-19 patients will suppress the SARS-CoV-2 viral load. Adjunctive therapy with corticosteroid and convalescent plasma might further ameliorate the cytokine response. Further randomized clinical trials of combination therapy are needed.