Real-world effectiveness of molnupiravir and nirmatrelvir plus ritonavir against mortality, hospitalisation, and in-hospital outcomes among community-dwelling, ambulatory patients with confirmed SARS-CoV-2 infection during the omicron wave in Hong Kong: an observational study

Real-world effectiveness of molnupiravir, azvudine and paxlovid against mortality and viral clearance among hospitalized patients with COVID-19 infection during the omicron wave in China: A retrospective cohort study

OBJECTIVES

In this retrospective cohort study, we aimed to assess clinical effectiveness and viral clearance following the use of molnupiravir, azvudine and paxlovid in hospitalized patients with COVID-19 in China dominated by the omicron BA.5.2 and BF.7 subvariant of SARS-CoV-2.

METHODS

Enrolled patients were assigned to the molnupiravir group or the azvudine group or the paxlovid group or the control group (not taking any antiviral drugs). The primary outcome of the cohort study was viral clearance and viral burden rebound after treatment and the secondary outcome was 28-day all-cause mortality. The four groups were propensity score-matched (1:1). We plotted viral load trends for each antiviral drug intervention using locally weighted regression (LOWESS) smoothed data. Multivariate logistic regression (stepwise algorithm) models were used to determine any risk factors for 28-day mortality.

RESULTS

Of the 1537 patients receiving any treatment, 886 (57.6 %) received molnupiravir, 390 (25.4 %) received azvudine, 94 (6.1 %) received paxlovid, and 167 (10.9 %) did not use any antiviral drugs. Our data analysis showed that age (OR = 1.05, 95 % CI: 1.03-1.07, P < 0.001), Charlson comorbidty index (OR = 1.32, 95 % CI: 1.18-1.48, P < 0.001), severity of COVID-19 (P < 0.001), gamma globulin (OR = 2.04, 95 % CI: 1.03-3.99, P = 0.039) and corticosteroids use (OR = 2.3, 95 % CI: 1.19-4.69, P = 0.017) were independent prognostic factors for 28-day mortality in COVID-19 patients. After propensity score matching (PSM), the paxlovid recipients (OR = 0.22, 95 % CI: 0.05-0.83, P = 0.036) or azvudine recipients (OR = 0.27, 95 % CI: 0.07-0.91, P = 0.046) had lower 28-day mortality compared to their matched controls. Viral rebound occurred in the control group around days 9-16, while no viral rebound was found in any of the three oral antiviral groups. We found that molnupiravir group performed comparably in terms of the rate of nucleic acid conversion negative compared with the paxlovid group, while azvudine group performed slightly worse compared with the paxlovid group or molnupiravir group.

CONCLUSIONS

In our retrospective cohort of hospitalized patients with COVID-19 during the wave of omicron strain, the molnupiravir, paxlovid and azvudine recipients showed a faster and more stable decrease in viral load and rare virus rebound in response to antiviral treatments when compared to the controls. The study supported that initiation treatment with paxlovid and azvudine was associated with significantly lower risk of all-cause death within 28 days.

Cost-effectiveness of nirmatrelvir/ritonavir for high-risk adult outpatients with COVID-19 in Japan

INTRODUCTION

This study aimed to evaluate the cost-effectiveness of nirmatrelvir/ritonavir (Nir/Rit) for adult outpatients with COVID-19 from the perspective of a Japanese public healthcare payer.

METHODS

A cost-effectiveness simulation was conducted comparing Nir/Rit for the outpatient treatment of high-risk COVID-19 patients to best supportive care (BSC) without antiviral or antibody drugs. The analytical model was divided into two phases: the treatment phase, lasting 35 days from the start of COVID-19 treatment, and the post-treatment phase. Patients who survived the treatment phase were assumed to follow a general population survival curve. Expected costs and expected quality-adjusted life years (QALYs) for both BSC and Nir/Rit were calculated for ages 40 to 80 to obtain the incremental cost-effectiveness ratio (ICER). The robustness of the results was evaluated through deterministic and probabilistic sensitivity analysis (PSA).

RESULTS

The ICERs for patients aged 40, 50, 60, 70, and 80 were 18,854,276 Japanese Yen (JPY)/QALY, 8,482,034 JPY/QALY, 4,976,612 JPY/QALY, 2,636,096 JPY/QALY, and 1,597,783 JPY/QALY, respectively. In the deterministic sensitivity analysis, both the mortality risk during the treatment phase and the relative mortality risk with Nir/Rit had a high impact on ICER across all ages. In the PSA, when the willingness-to-pay (WTP) threshold was set at 5 million JPY/QALY, the probability of the ICER being below the WTP threshold was 0%, 0.2%, 45.4%, 99.9%, and 100% at ages 40, 50, 60, 70, and 80, respectively.

CONCLUSION

Nir/Rit is cost-effective for older individuals aged 60 and over but not for younger age groups.

Association between asthma and COVID-19 severity during Omicron epidemic: a retrospective cohort study using real-world data

BACKGROUND

The available evidence presented inconsistencies and inconclusive findings regarding the associations between co-existing asthma and mortality among COVID-19 patients. The objective of the current study is to investigate the relationship between asthma and severe outcomes after SARS-CoV-2 Omicron infection in an infection-naïve population.

METHODS

A retrospective cohort study using propensity score matching was conducted. The COVID-19 patients requiring hospitalisation in Hong Kong from January 1, 2022, to November 13, 2022, an Omicron-predominated period, were identified. Severe clinical outcomes were defined as ICU admission and inpatient death after the first positive PCR results as well as a composite outcome of both.

RESULTS

Of the 74,396 hospitalised COVID-19 patients admitted, 1,290 asthma patients and 18,641 non-asthma patients were included in the matched cohort. The rates of death and the composite outcome were 15·3% and 17·2%, respectively, among the non-asthma patients,12·2% and 13·6%, respectively, among the asthma patients, with adjusted hazard ratios equal to 0·775 (95% CI: 0·660-0·909) and 0·770 (95% CI: 0·662-0·895), respectively. The negative association was more apparent in the elderly and female groups. Asthma remained a factor that lowered the risk of disease severity even though the patients were not fully vaccinated with at least two doses.

CONCLUSIONS

We used real-world data to demonstrate that asthma was not a risk factor for COVID-19 severity of the infections of Omicron variant, even though the patients were not fully vaccinated.

COVID-19 drug discovery and treatment options

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused substantial morbidity and mortality, and serious social and economic disruptions worldwide. Unvaccinated or incompletely vaccinated older individuals with underlying diseases are especially prone to severe disease. In patients with non-fatal disease, long COVID affecting multiple body systems may persist for months. Unlike SARS-CoV and Middle East respiratory syndrome coronavirus, which have either been mitigated or remained geographically restricted, SARS-CoV-2 has disseminated globally and is likely to continue circulating in humans with possible emergence of new variants that may render vaccines less effective. Thus, safe, effective and readily available COVID-19 therapeutics are urgently needed. In this Review, we summarize the major drug discovery approaches, preclinical antiviral evaluation models, representative virus-targeting and host-targeting therapeutic options, and key therapeutics currently in clinical use for COVID-19. Preparedness against future coronavirus pandemics relies not only on effective vaccines but also on broad-spectrum antivirals targeting conserved viral components or universal host targets, and new therapeutics that can precisely modulate the immune response during infection.

COVID-19 in patients with myasthenia gravis: a single-center retrospective study in China

BACKGROUND

Coronavirus disease 2019 (COVID-19) has been a great concern since 2019. Patients with myasthenia gravis (MG) may be at higher risk of COVID-19 and a more severe disease course. We examined the associations between COVID-19 and MG.

METHODS

This single-center retrospective cohort study involved 134 patients who were diagnosed with MG from June 2020 to November 2022 and followed up until April 2023. They were divided into a COVID-19 group and non-COVID-19 group. Logistic regression analysis was used to detect factors potentially associating COVID-19 with MG.

RESULTS

Of the 134 patients with MG, 108 (80.6%) had COVID-19. A higher number of comorbidities was significantly associated with an increased risk of COVID-19 (p = 0.040). A total of 103 patients (95.4%) had mild/moderate COVID-19 symptoms, and 4 patients (3.7%) were severe/critical symptoms (including 2 deaths). Higher age (p = 0.036), use of rituximab (p = 0.037), tumors other than thymoma (p = 0.031), Hashimoto's thyroiditis (p = 0.011), more comorbidities (p = 0.002), and a higher baseline MG activities of daily living (MG-ADL) score (p = 0.006) were risk factors for severe COVID-19 symptoms. The MG-ADL score increased by ≥ 2 points in 16 (15.7%) patients. Dry cough and/or expectoration (p = 0.011), use of oral corticosteroids (p = 0.033), and use of more than one kind of immunosuppressant (p = 0.017) were associated with the increase of the post-COVID-19 MG-ADL score.

CONCLUSION

Most patients with MG have a mild course of COVID-19. However, patients with older age, many comorbidities, a high MG-ADL score, and use of a variety of immunosuppressants during COVID-19 may be more prone to severe symptoms.

Real-world severe COVID-19 outcomes associated with use of antivirals and neutralising monoclonal antibodies in Scotland

We sought to investigate the incidence of severe COVID-19 outcomes after treatment with antivirals and neutralising monoclonal antibodies, and estimate the comparative effectiveness of treatments in community-based individuals. We conducted a retrospective cohort study investigating clinical outcomes of hospitalisation, intensive care unit admission and death, in those treated with antivirals and monoclonal antibodies for COVID-19 in Scotland between December 2021 and September 2022. We compared the effect of various treatments on the risk of severe COVID-19 outcomes, stratified by most prevalent sub-lineage at that time, and controlling for comorbidities and other patient characteristics. We identified 14,365 individuals treated for COVID-19 during our study period, some of whom were treated for multiple infections. The incidence of severe COVID-19 outcomes (inpatient admission or death) in community-treated patients (81% of all treatment episodes) was 1.2% (n = 137/11894, 95% CI 1.0-1.4), compared to 32.8% in those treated in hospital for acute COVID-19 (re-admissions or death; n = 40/122, 95% CI 25.1-41.5). For community-treated patients, there was a lower risk of severe outcomes (inpatient admission or death) in younger patients, and in those who had received three or more COVID-19 vaccinations. During the period in which BA.2 was the most prevalent sub-lineage in the UK, sotrovimab was associated with a reduced treatment effect compared to nirmaltrelvir + ritonavir. However, since BA.5 has been the most prevalent sub-lineage in the UK, both sotrovimab and nirmaltrelvir + ritonavir were associated with similarly lower incidence of severe outcomes than molnupiravir. Around 1% of those treated for COVID-19 with antivirals or neutralising monoclonal antibodies required hospital admission. During the period in which BA.5 was the prevalent sub-lineages in the UK, molnupiravir was associated with the highest incidence of severe outcomes in community-treated patients.

Real-World Effectiveness of Ensitrelvir in Reducing Severe Outcomes in Outpatients at High Risk for COVID-19

INTRODUCTION

This study aimed to evaluate the effectiveness of ensitrelvir, an oral antiviral, in reducing hospitalization risk in outpatients at high-risk for severe COVID-19 during the Omicron era.

METHODS

This was a retrospective study using a large Japanese health insurance claims database. It included high-risk outpatients for severe symptoms who received their first COVID-19 diagnosis between November 2022 and July 2023. The study included outpatients aged ≥ 18 years. The primary endpoint was all-cause hospitalization during the 4-week period from the date of outpatient diagnosis and medication, comparing the ensitrelvir group (n = 5177) and the no antiviral treatment group (n = 162,133). The risk ratio and risk difference were evaluated after adjusting patient background distribution by the inverse probability of treatment weight (IPTW) method. Secondary endpoints were incidence of respiratory and heart rate monitoring, oxygen therapy, ventilator use, intensive care admission, and all-cause death.

RESULTS

The risk ratio for all-cause hospitalization between the ensitrelvir group (n = 167,385) and the no antiviral treatment group (n = 167,310) after IPTW adjustment was 0.629 [95% confidence interval (CI) 0.420, 0.943]. The risk difference was - 0.291 [95% CI - 0.494, - 0.088]. The incidence of both respiratory and heart rate monitoring and oxygen therapy was lower in the ensitrelvir group. Ventilator use, intensive care admission, and all-cause death were difficult to assess because of the limited events.

CONCLUSIONS

The incidence of all-cause hospitalization was significantly lower in the ensitrelvir group than in the no antiviral treatment group, suggesting ensitrelvir is an effective treatment in patients at risk of severe COVID-19.

Effectiveness and Safety of Molnupiravir in the Intended-Use Population: an Observational Cohort Study

OBJECTIVES

Previous research reported inconsistent results on the efficacy of molnupiravir in treating COVID-19. Moreover, efficacy was not assessed in the intended-use population (IUP), as defined by the FDA. Therefore, we aimed to evaluate the effectiveness and safety of molnupiravir for the treatment of COVID-19 in the IUP.

METHODS

We conducted a retrospective cohort study on all IUP in Israel's Clalit Health Services (CHS) from Jan. 16, 2022, to Feb. 16, 2023. The effectiveness outcome was the incidence of hospitalization or death due to COVID-19, and the safety outcome was the incidence of all-cause mortality within 35 days of SARS-CoV-2 infection. Cox-proportional hazard models were used to analyze the data after 1:5 propensity score matching.

RESULTS

49,515 patients met the eligibility criteria. Of them, 3,957 molnupiravir-treated patients were matched to 19,785 untreated patients. In molnupiravir-treated patients, 70 out of 3,957 (5.1 per 10,000 person-days) experienced COVID-19-related hospitalization or death, compared to 699 out of 19,785 untreated patients (10.4 per 10,000 person-days); RR: 0.50, (95% CI: 0.39-0.64). All-cause mortality was also lower in the treated group, with 41 out of 3,957 (3.0 per 10,000 person-days) experiencing mortality compared to 414 out of 19,785 untreated patients (6.1 per 10,000 person-days); RR: 0.50 (0.36-0.68).

CONCLUSIONS

In a real-world cohort of IUP, molnupiravir therapy was associated with a significant reduction in hospitalizations or deaths due to COVID-19 and all-cause mortality.

Perceived Risk for Severe COVID-19 and Oral Antiviral Use Among Antiviral-Eligible US Adults

INTRODUCTION

Oral antiviral medications are important tools for preventing severe COVID-19 outcomes. However, their uptake remains low for reasons that are not entirely understood. Our study aimed to assess the association between perceived risk for severe COVID-19 outcomes and oral antiviral use among those who were eligible for treatment based on Centers for Disease Control and Prevention (CDC) guidelines.

METHODS

We surveyed 4034 non-institutionalized US adults in April 2023, and report findings from 934 antiviral-eligible participants with at least one confirmed SARS-CoV-2 infection since December 1, 2021 and no current long COVID symptoms. Survey weights were used to yield nationally representative estimates. The primary exposure of interest was whether participants perceived themselves to be "at high risk for severe COVID-19." The primary outcome was use of a COVID-19 oral antiviral within 5 days of suspected SARS-CoV-2 infection.

RESULTS

Only 18.5% of antiviral-eligible adults considered themselves to be at high risk for severe COVID-19 and 16.8% and 15.9% took oral antivirals at any time or within 5 days of SARS-CoV-2 infection, respectively. In contrast, 79.8% were aware of antiviral treatments for COVID-19. Perceived high-risk status was associated with being more likely to be aware (adjusted prevalence ratio [aPR]: 1.11 [95% confidence interval (CI) 1.03-1.20]), to be prescribed (aPR 1.47 [95% CI 1.08-2.01]), and to take oral antivirals at any time (aPR 1.61 [95% CI 1.16-2.24]) or within 5 days of infection (aPR 1.72 [95% CI 1.23-2.40]).

CONCLUSIONS

Despite widespread awareness of the availability of COVID-19 oral antivirals, more than 80% of eligible US adults did not receive them. Our findings suggest that differences between perceived and actual risk for severe COVID-19 (based on current CDC guidelines) may partially explain this low uptake.

COVID-19 therapeutics

SUMMARYSince the emergence of COVID-19 in 2020, an unprecedented range of therapeutic options has been studied and deployed. Healthcare providers have multiple treatment approaches to choose from, but efficacy of those approaches often remains controversial or compromised by viral evolution. Uncertainties still persist regarding the best therapies for high-risk patients, and the drug pipeline is suffering fatigue and shortage of funding. In this article, we review the antiviral activity, mechanism of action, pharmacokinetics, and safety of COVID-19 antiviral therapies. Additionally, we summarize the evidence from randomized controlled trials on efficacy and safety of the various COVID-19 antivirals and discuss unmet needs which should be addressed.

Effectiveness of nirmatrelvir/ritonavir in children and adolescents aged 12-17 years following SARS-CoV-2 Omicron infection: A target trial emulation

Currently there is a lack of randomized trial data examining the use of the antiviral nirmatrelvir/ritonavir in paediatric patients with SARS-CoV-2 infection. This target trial emulation study aims to address this gap by evaluating the use of nirmatrelvir/ritonavir in non-hospitalized paediatric patients aged 12-17 years with SARS-CoV-2 Omicron variant infection. Among paediatric patients diagnosed between 16th March 2022 and 5th February 2023, exposure was defined as outpatient nirmatrelvir/ritonavir treatment within 5 days of symptom onset or COVID-19 diagnosis. Primary outcome was 28 day all-cause mortality or all-cause hospitalization, while secondary outcomes were 28 day in-hospital disease progression, 28 day COVID-19-specific hospitalization, multisystem inflammatory syndrome in children (MIS-C), acute liver injury, acute renal failure, and acute respiratory distress syndrome. Overall, 49,378 eligible paediatric patients were included. Nirmatrelvir/ritonavir treatment was associated with reduced 28 day all-cause hospitalization (absolute risk reduction = 0.23%, 95%CI = 0.19%-0.31%; relative risk = 0.66, 95%CI = 0.56-0.71). No events of mortality, in-hospital disease progression, or adverse clinical outcomes were observed among nirmatrelvir/ritonavir users. The findings confirmed the effectiveness of nirmatrelvir/ritonavir in reducing all-cause hospitalization risk among non-hospitalized pediatric patients with SARS-CoV-2 Omicron variant infection.

Natural hyperoside extracted from hawthorn exhibits antiviral activity against porcine epidemic diarrhea virus in vitro and in vivo

Porcine epidemic diarrhea virus (PEDV) causes severe diarrhea and death in piglets, resulting in significant economic losses for the pork industry. There is an urgent need for new treatment strategies. Here, we focused on optimizing the process of purifying natural hyperoside (nHYP) from hawthorn and evaluating its effectiveness against PEDV both in vitro and in vivo. Our findings demonstrated that nHYP with a purity >98% was successfully isolated from hawthorn with an extraction rate of 0.42 mg/g. Furthermore, nHYP exhibited strong inhibitory effects on PEDV replication in cells, with a selection index of 9.72. nHYP significantly reduced the viral load in the intestines of piglets and protected three of four piglets from death caused by PEDV infection. Mechanistically, nHYP could intervene in the interaction of PEDV N protein and p53. The findings implicate nHYP as having promising therapeutic potential for combating PEDV infections.

Joint analysis of vaccination effectiveness and antiviral drug effectiveness for COVID-19: a causal inference approach

OBJECTIVES

This study aims to estimate the causal effects of oral antivirals and vaccinations in the prevention of all-cause mortality and progression to severe COVID-19 in an integrative setting with both antivirals and vaccinations considered as interventions.

METHODS

We identified hospitalized adult patients (i.e. aged 18 or above) in Hong Kong with confirmed SARS-CoV-2 infection between March 16, 2022, and December 31, 2022. An inverse probability-weighted (IPW) Andersen-Gill model with time-dependent predictors was used to address immortal time bias and produce causal estimates for the protection effects of oral antivirals and vaccinations against severe COVID-19.

RESULTS

Given prescription is made within 5 days of confirmed infection, nirmatrelvir-ritonavir is more effective in providing protection against all-cause mortality and development into severe COVID-19 than molnupiravir. There was no significant difference between CoronaVac and Comirnaty in the effectiveness of reducing all-cause mortality and progression to severe COVID-19.

CONCLUSIONS

The use of oral antivirals and vaccinations causes lower risks of all-cause mortality and progression to severe COVID-19 for hospitalized SARS-CoV-2 patients.

Molnupiravir for the treatment of COVID-19 outpatients: An updated meta-analysis

BACKGROUND

The majority of available data on molnupiravir come from an unvaccinated COVID-19 population. Therefore, we conducted this meta-analysis to integrate evidence from recent randomized controlled trials (RCTs) as well as observational studies stratified by vaccination status to determine the clinical efficacy and safety of molnupiravir in COVID-19 outpatients.

METHODS

We searched PubMed, Embase, the Cochrane Library, medRxiv, and ClinicalTrials.gov from inception to November 2023. We conducted our meta-analysis using RevMan 5.4 with risk ratio (RR) as the effect measure.

RESULTS

We included 8 RCTs and 5 observational studies in our meta-analysis. Molnupiravir reduced the risk of all-cause mortality (RR 0.28; 95% CI: 0.20-0.79, I2 = 0%) but did not decrease the hospitalization rate (RR 0.67; 95% CI: 0.45-1.00, I2 = 53%) in the overall population; in the immunized population, no benefits were observed. Molnupiravir lowered the rate of no recovery (RR 0.78; 95% CI: 0.76-0.81, I2 = 0%) and increased virological clearance at day 5 (RR 2.68; 95% CI: 1.94-4.22, I2 = 85%). There was no increase in the incidence of adverse events.

CONCLUSIONS

Molnupiravir does not decrease mortality and hospitalization rates in immunized patients with COVID-19. However, it does shorten the disease course and increases the recovery rate. The use of molnupiravir will need to be considered on a case-by-case basis in the context of the prevailing social circumstances, the resource setting, drug costs, and the healthcare burden.

Molnupiravir Use Among Patients with COVID-19 in Real-World Settings: A Systematic Literature Review

INTRODUCTION

Molnupiravir (MOV) is an oral antiviral for the treatment of individuals with mild-to-moderate COVID-19 and at high risk of progression to severe disease. Our objective was to conduct a systematic literature review (SLR) of evidence on the effectiveness of MOV in reducing the risk of severe COVID-19 outcomes in real-world outpatient settings.

METHODS

The SLR was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines and using pre-determined population, intervention, comparison, outcome, time, and study design inclusion criteria. Eligible studies were published between January 1, 2021, and March 10, 2023, and evaluated the real-world effectiveness of MOV compared to no treatment in reducing the risk of severe COVID-19 outcomes among outpatients ≥ 18 years of age with a laboratory-confirmed diagnosis of SARS-CoV-2 infection.

RESULTS

Nine studies from five countries were included in the review. The size of the MOV-treated group ranged from 359 to 7818 individuals. Omicron variants of SARS-CoV-2 were dominant in all study periods. Most studies noted differences in the baseline characteristics of the MOV-treated and untreated control groups, with the treated groups generally being older and with more comorbidities. Eight studies reported that treatment with MOV was associated with a significantly reduced risk of at least one severe COVID-19 outcome in at least one age group, with greater benefits consistently observed among older age groups.

CONCLUSIONS

In this SLR study, treatment with MOV was effective in reducing the risk of severe outcomes from COVID-19 caused by Omicron variants, especially for older individuals. Differences in the ages and baseline comorbidities of the MOV-treated and control groups may have led to underestimation of the effectiveness of MOV in many observational studies. Real-world studies published to date thus provide additional evidence supporting the continued benefits of MOV in non-hospitalized adults with COVID-19.

Effectiveness of nirmatrelvir/ritonavir and molnupiravir in non-hospitalized adults with COVID-19: systematic review and meta-analysis of observational studies

OBJECTIVE

To determine the effectiveness of nirmatrelvir/ritonavir and molnupiravir among vaccinated and unvaccinated non-hospitalized adults with COVID-19.

METHODS

Observational studies of nirmatrelvir/ritonavir or molnupiravir compared to no antiviral drug treatment for COVID-19 in non-hospitalized adults with data on vaccination status were included. We searched MEDLINE, EMBASE, Scopus, Web of Science, WHO COVID-19 Research Database and medRxiv for reports published between 1 January 2022 and 8 November 2023. The primary outcome was a composite of hospitalization or mortality up to 35 days after COVID-19 diagnosis. Risk of bias was assessed with ROBINS-I. Risk ratios (RR), hazard ratios (HR) and risk differences (RD) were separately estimated using random-effects models.

RESULTS

We included 30 cohort studies on adults treated with nirmatrelvir/ritonavir (n = 462 279) and molnupiravir (n = 48 008). Nirmatrelvir/ritonavir probably reduced the composite outcome (RR 0.62, 95%CI 0.55-0.70; I2 = 0%; moderate certainty) with no evidence of effect modification by vaccination status (RR Psubgroup = 0.47). In five studies, RD estimates against the composite outcome for nirmatrelvir/ritonavir were 1.21% (95%CI 0.57% to 1.84%) in vaccinated and 1.72% (95%CI 0.59% to 2.85%) in unvaccinated subgroups.Molnupiravir may slightly reduce the composite outcome (RR 0.75, 95%CI 0.67-0.85; I2 = 32%; low certainty). Evidence of effect modification by vaccination status was inconsistent among studies reporting different effect measures (RR Psubgroup = 0.78; HR Psubgroup = 0.08). In two studies, RD against the composite outcome for molnupiravir were -0.01% (95%CI -1.13% to 1.10%) in vaccinated and 1.73% (95%CI -2.08% to 5.53%) in unvaccinated subgroups.

CONCLUSIONS

Among cohort studies of non-hospitalized adults with COVID-19, nirmatrelvir/ritonavir is effective against the composite outcome of severe COVID-19 independent of vaccination status. Further research and a reassessment of molnupiravir use among vaccinated adults are warranted.

REGISTRATION

PROSPERO CRD42023429232.

Combination of spironolactone and DPP-4 inhibitors for treatment of SARS-CoV-2 infection: a literature review

Coronavirus disease 2019 (COVID-19) is still causing hospitalization and death, and vaccination appears to become less effective with each emerging variant. Spike, non-spike, and other possible unrecognized mutations have reduced the efficacy of recommended therapeutic approaches, including monoclonal antibodies, plasma transfusion, and antivirals. SARS-CoV-2 binds to angiotensin-converting enzyme 2 (ACE2) and probably dipeptidyl peptidase 4 (DPP-4) to initiate the process of endocytosis by employing host proteases such as transmembrane serine protease-2 (TMPRSS-2) and ADAM metallopeptidase domain 17 (ADAM17). Spironolactone reduces the amount of soluble ACE2 and antagonizes TMPRSS-2 and ADAM17. DPP-4 inhibitors play immunomodulatory roles and may block viral entry. The efficacy of treatment with a combination of spironolactone and DPP-4 inhibitors does not appear to be affected by viral mutations. Therefore, the combination of spironolactone and DPP-4 inhibitors might improve the clinical outcome for COVID-19 patients by decreasing the efficiency of SARS-CoV-2 entry into cells and providing better anti-inflammatory, antiproliferative, and antifibrotic effects than those achieved using current therapeutic approaches such as antivirals and monoclonal antibodies.

Symptoms, Viral Loads, and Rebound Among COVID-19 Outpatients Treated With Nirmatrelvir/Ritonavir Compared With Propensity Score-Matched Untreated Individuals

BACKGROUND

Nirmatrelvir/ritonavir (N/R) reduces severe outcomes from coronavirus disease 2019 (COVID-19); however, rebound after treatment has been reported. We compared symptom and viral dynamics in individuals with COVID-19 who completed N/R treatment and similar untreated individuals.

METHODS

We identified symptomatic participants who tested severe acute respiratory syndrome coronavirus 2-positive and were N/R eligible from a COVID-19 household transmission study. Index cases from ambulatory settings and their households contacts were enrolled. We collected daily symptoms, medication use, and respiratory specimens for quantitative polymerase chain reaction for 10 days during March 2022-May 2023. Participants who completed N/R treatment (treated) were propensity score matched to untreated participants. We compared symptom rebound, viral load (VL) rebound, average daily symptoms, and average daily VL by treatment status measured after N/R treatment completion or 7 days after symptom onset if untreated.

RESULTS

Treated (n = 130) and untreated participants (n = 241) had similar baseline characteristics. After treatment completion, treated participants had greater occurrence of symptom rebound (32% vs 20%; P = .009) and VL rebound (27% vs 7%; P < .001). Average daily symptoms were lower among treated participants without symptom rebound (1.0 vs 1.6; P < .01) but not statistically lower with symptom rebound (3.0 vs 3.4; P = .5). Treated participants had lower average daily VLs without VL rebound (0.9 vs 2.6; P < .01) but not statistically lower with VL rebound (4.8 vs 5.1; P = .7).

CONCLUSIONS

Individuals who completed N/R treatment experienced fewer symptoms and lower VL but rebound occured more often compared with untreated individuals. Providers should prescribe N/R, when indicated, and communicate rebound risk to patients.

Real-World Efficacy of Ensitrelvir in Hospitalized Patients With COVID-19 in Japan: A Retrospective Observational Study

BACKGROUND AND AIM

The coronavirus disease 2019 (COVID-19) pandemic necessitates continuously evaluating antiviral treatments, especially for high-risk groups, including older individuals. This study aimed to compare the efficacy of three antiviral drugs, including remdesivir, molnupiravir, and ensitrelvir, in hospitalized patients as measured by our own institution's antigen test, focusing on outcomes, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antigen levels, hospitalization duration, and fever resolution.

METHODS

This retrospective observational study was conducted at Yoshida Hospital, Asahikawa City, Japan, enrolling 154 patients who received antiviral treatment upon COVID-19 diagnosis from July 1, 2022, to September 15, 2023. The diagnosis was confirmed by proprietary antigen tests or loop-mediated isothermal amplification assays. Patients who received treatment outside the hospital or with consistently negative antigen results were excluded. Drug administration was determined by attending physicians, considering oral administration challenges and renal dysfunction. The data were statistically analyzed using an unpaired two-tailed Student's t-test and one-way analysis of variance complemented by the Tukey post-hoc test for detailed group comparisons.

RESULTS

No significant differences were observed in the initial antigen levels among the treatment groups. By day 10, the ensitrelvir group showed lower antigen levels than the other groups, but not significantly. The ensitrelvir group had a higher antigen-negative conversion rate and a significantly shorter hospital stay than the molnupiravir group. However, no significant differences were noted in the fever resolution time among the groups.

CONCLUSION

This study suggests the potential benefits of ensitrelvir in reducing antigen levels and hospitalization duration. However, the overall efficacy of the antiviral agents for symptomatic relief appears similar. These findings underscore the need for further research to optimize COVID-19 management by considering personalized treatment approaches and long-term outcomes.

New conjugates based on N4-hydroxycytidine with more potent antiviral efficacy in vitro than EIDD-2801 against SARS-CoV-2 and other human coronaviruses

The spread of COVID-19 continues due to genetic variation in SARS-CoV-2. Highly mutated variants of SARS-CoV-2 have an increased transmissibility and immune evasion. Due to the emergence of various new variants of the virus, there is an urgent need to develop broadly effective specific drugs for therapeutic strategies for the prevention and treatment of COVID-19. Molnupiravir (EIDD-2801, MK-4482), is an orally bioavailable ribonucleoside analogue of β-D-N4-hydroxycytidine (NHC), has demonstrated efficacy against SARS-CoV-2 and was recently approved for COVID-19 treatment. To improve antiviral potency of NHC, we developed a panel of NHC conjugates with lipophilic vectors and ester derivatives with amino- and carboxylic-acids. Most of the synthesized compounds had comparable or higher (2-20 times) antiviral activity than EIDD-2801, against different lineages of SARS-CoV-2, MERS-CoV, seasonal coronaviruses OC43 and 229E, as well as bovine coronavirus. For further studies, we assessed the most promising compound in terms of activity, simplicity and cost of synthesis - NHC conjugate with phenylpropionic acid (SN_9). SN_9 has shown high efficacy in prophylactic, therapeutic and transmission models of COVID-19 infection in hamsters. Importantly, SN_9 profoundly inhibited virus replication in the lower respiratory tract of hamsters and transgenic mice infected with the Omicron sublineages XBB.1.9.1, XBB.1.16 and EG.5.1.1. These data indicate that SN_9 represents a promising antiviral drug candidate for COVID-19 treatment, and NHC modification strategies deserve further investigation as an approach to develop prodrugs against various coronaviruses.

Effectiveness of Nirmatrelvir-Ritonavir for the Prevention of COVID-19-Related Hospitalization and Mortality: A Systematic Literature Review

BACKGROUND

Nirmatrelvir/ritonavir (NMV/r) is an oral antiviral drug used to treat mild-to-moderate coronavirus disease 2019 (COVID-19) in patients aged 12 years or older at high risk of progression to severe disease (eg, hospitalization and death). Despite being the preferred option for outpatient treatment in the majority of countries worldwide, NMV/r is currently underutilized in real-world clinical practice.

AREAS OF UNCERTAINTY

As numerous real-world studies have described patient outcomes following treatment with NMV/r, this systematic literature review provides a comprehensive summary of evidence on NMV/r effectiveness against hospitalization and mortality further organized by clinically meaningful categories, such as acute versus longer-term follow-up, age, underlying health conditions, and vaccination status, to help inform health care decision making.

DATA SOURCES

We searched Embase and PubMed (December 22, 2021-March 31, 2023) and congress abstracts (December 1, 2021-December 31, 2022) for reports describing NMV/r effectiveness.

THERAPEUTIC ADVANCES

In total, 18 real-world studies met final selection criteria. The evidence showed that NMV/r significantly reduced postinfection risk of all-cause and COVID-19-related hospitalization and mortality in both acute (≤30 days) (21%-92%) and longer-term (>30 days) (1%-61%) follow-up. The reduction in postinfection risk was higher when treatment was received within 5 days of symptom onset. Real-world effectiveness of NMV/r treatment was observed regardless of age, underlying high-risk conditions, and vaccination status.

CONCLUSION

The systematic literature review findings demonstrated the effectiveness of NMV/r against hospitalization and mortality during the Omicron period among individuals at high risk of progression to severe COVID-19 disease.

Real-world application of nirmatrelvir/ritonavir in hospitalized COVID-19 patients with onset of symptoms beyond 5 days: a comparative study

PURPOSE

Physicians may administer Nirmatrelvir-ritonavir to patients who have been symptomatic for more than 5 days. There is currently no clear evidence to support this approach.

METHODS

A real-world study was conducted to investigate the potential relationship between the administration of Nirmatrelvir-ritonavir and the rates of intubation or in-hospital mortality among COVID-19 patients who experienced symptoms for more than 5 days. The end point was a composite event of intubation or in-hospital mortality. The outcomes between those patients who received Nirmatrelvir-ritonavir and those who did not were compared.

RESULTS

A total of 847 patients were included in the analysis. Among them, 312 patients (36.84%) received Nirmatrelvir-ritonavir. Within the entire population, 86 patients (10.15%) experienced intubation or in-hospital mortality. The main analysis indicated that there was a significant association between the application of Nirmatrelvir-ritonavir and intubation or in-hospital mortality, with an odds ratio of 0.50 (95% confidence interval, 0.28 to 0.87; P = 0.0153) using inverse probability of treatment weighting. The finding was consistent with multiple sensitivity analyses.

CONCLUSIONS

The application of Nirmatrelvir-ritonavir was associated with a significantly reduced risk of intubation or death in hospitalized COVID-19 patients who experienced symptoms for more than 5 days as compared to those who did not receive the treatment.

Review: The Landscape of Antiviral Therapy for COVID-19 in the Era of Widespread Population Immunity and Omicron-Lineage Viruses

The goals of coronavirus disease 2019 (COVID-19) antiviral therapy early in the pandemic were to prevent severe disease, hospitalization, and death. As these outcomes have become infrequent in the age of widespread population immunity, the objectives have shifted. For the general population, COVID-19-directed antiviral therapy should decrease symptom severity and duration and minimize infectiousness, and for immunocompromised individuals, antiviral therapy should reduce severe outcomes and persistent infection. The increased recognition of virologic rebound following ritonavir-boosted nirmatrelvir (NMV/r) and the lack of randomized controlled trial data showing benefit of antiviral therapy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection for standard-risk, vaccinated individuals remain major knowledge gaps. Here, we review data for selected antiviral agents and immunomodulators currently available or in late-stage clinical trials for use in outpatients. We do not review antibody products, convalescent plasma, systemic corticosteroids, IL-6 inhibitors, Janus kinase inhibitors, or agents that lack Food and Drug Administration approval or emergency use authorization or are not appropriate for outpatients.

The effectiveness of novel oral antiviral treatment for non-hospitalized high-risk patients with COVID-19 during predominance of omicron XBB subvariants

OBJECTIVES

This study investigated the association between nirmatrelvir plus ritonavir (NMV-r) or molnupiravir and the outcomes of non-hospitalized high-risk patients with COVID-19 during Omicron XBB subvariants.

METHODS

The retrospective cohort study used the TriNetX US collaborative network to identify non-hospitalized high-risk adult patients with COVID-19 between 1 February 2023, and 31 August 2023. Propensity score matching (PSM) was used to match patients receiving NMV-r or MOV (the study group) with those not receiving antivirals (the control group).

RESULTS

Using PSM, two cohorts of 17,654 patients each with balanced baseline characteristics were identified. During the follow-up period, the study group had a lower risk of all-cause hospitalization, or death (3.2% [n = 564] versus 3.8% [n = 669]; HR, 0.796; 95% confidence interval [CI], 95% CI, 0.712-0.891). Compared with the control group, the study group had a significantly lower risk of all-cause hospitalization (3.1% vs. 3.4%; HR, 0.847; 95% CI, 0.754-0.950) and mortality (0.1% vs. 0.4%; HR, 0.295; 95% CI, 0.183-0.476).

CONCLUSION

The use of novel oral antiviral including NMV-r or MOV can be associated with a lower risk of all-cause hospitalization, or death in non-hospitalized high-risk patients with COVID-19 during Omicron XBB wave.

Nirmatrelvir for Vaccinated or Unvaccinated Adult Outpatients with Covid-19

BACKGROUND

Nirmatrelvir in combination with ritonavir is an antiviral treatment for mild-to-moderate coronavirus disease 2019 (Covid-19). The efficacy of this treatment in patients who are at standard risk for severe Covid-19 or who are fully vaccinated and have at least one risk factor for severe Covid-19 has not been established.

METHODS

In this phase 2-3 trial, we randomly assigned adults who had confirmed Covid-19 with symptom onset within the past 5 days in a 1:1 ratio to receive nirmatrelvir-ritonavir or placebo every 12 hours for 5 days. Patients who were fully vaccinated against Covid-19 and who had at least one risk factor for severe disease, as well as patients without such risk factors who had never been vaccinated against Covid-19 or had not been vaccinated within the previous year, were eligible for participation. Participants logged the presence and severity of prespecified Covid-19 signs and symptoms daily from day 1 through day 28. The primary end point was the time to sustained alleviation of all targeted Covid-19 signs and symptoms. Covid-19-related hospitalization and death from any cause were also assessed through day 28.

RESULTS

Among the 1296 participants who underwent randomization and were included in the full analysis population, 1288 received at least one dose of nirmatrelvir-ritonavir (654 participants) or placebo (634 participants) and had at least one postbaseline visit. The median time to sustained alleviation of all targeted signs and symptoms of Covid-19 was 12 days in the nirmatrelvir-ritonavir group and 13 days in the placebo group (P = 0.60). Five participants (0.8%) in the nirmatrelvir-ritonavir group and 10 (1.6%) in the placebo group were hospitalized for Covid-19 or died from any cause (difference, -0.8 percentage points; 95% confidence interval, -2.0 to 0.4). The percentages of participants with adverse events were similar in the two groups (25.8% with nirmatrelvir-ritonavir and 24.1% with placebo). In the nirmatrelvir-ritonavir group, the most commonly reported treatment-related adverse events were dysgeusia (in 5.8% of the participants) and diarrhea (in 2.1%).

CONCLUSIONS

The time to sustained alleviation of all signs and symptoms of Covid-19 did not differ significantly between participants who received nirmatrelvir-ritonavir and those who received placebo. (Supported by Pfizer; EPIC-SR ClinicalTrials.gov number, NCT05011513.).

Prevention and treatment strategies for kidney transplant recipients in the context of long-term existence of COVID-19

The sudden outbreak of coronavirus disease 2019 (COVID-19) in early 2020 posed a massive threat to human life and caused an economic upheaval worldwide. Kidney transplant recipients (KTRs) became susceptible to infection during the COVID-19 pandemic owing to their use of immunosuppressants, resulting in increased hospitalization and mortality rates. Although the current epidemic situation is alleviated, the long-term existence of COVID-19 still seriously threatens the life and health of KTRs with low immunity. The Omicron variant, a highly infectious but less-pathogenic strain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has raised concerns among transplant physicians regarding managing KTRs diagnosed with this variant. However, currently, there are no clear and unified guidelines for caring for KTRs infected with this variant. Therefore, we aimed to summarize the ongoing research on drugs that can treat Omicron variant infections in KTRs and explore the potential of adjusting immunotherapy strategies to enhance their responsiveness to vaccines. Herein, we discuss the situation of KTRs since the emergence of COVID-19 and focus on various prevention and treatment strategies for KTRs since the Omicron variant outbreak. We hope to assist physicians in managing KTRs in the presence of long-term COVID-19 variants.

COVID-19 hospitalization risk after outpatient nirmatrelvir/ritonavir use, January to August 2022, North Carolina

BACKGROUND

In the USA, nirmatrelvir/ritonavir is authorized for the treatment of mild-to-moderate COVID-19 in patients at least 12 years of age, at high risk for progression to severe COVID-19.

OBJECTIVES

To estimate the impact of outpatient nirmatrelvir/ritonavir on COVID-19 hospitalization risk in a US healthcare system.

METHODS

We conducted a cohort study using electronic health records among outpatients with a positive SARS-CoV-2 PCR test between January and August 2022. We evaluated the association of nirmatrelvir/ritonavir therapy with time to hospitalization by estimating adjusted HRs and assessed the impact of nirmatrelvir/ritonavir on predicted COVID-19 hospitalizations using machine-learning methods.

RESULTS

Among 44 671 patients, 4948 (11%) received nirmatrelvir/ritonavir, and 201 (0.4%) were hospitalized within 28 days of COVID-19 diagnosis. Nirmatrelvir/ritonavir recipients were more likely to be older, white, vaccinated, have comorbidities and reside in areas with higher average socioeconomic status. The 28 day cumulative incidence of hospitalization was 0.06% (95% CI: 0.02%-0.17%) among nirmatrelvir/ritonavir recipients and 0.52% (95% CI: 0.46%-0.60%) among non-recipients. For nirmatrelvir/ritonavir versus no therapy, the age-adjusted HR was 0.08 (95% CI: 0.03-0.26); the fully adjusted HR was 0.16 (95% CI: 0.05-0.50). In the machine-learning model, the primary features reducing predicted hospitalization risk were nirmatrelvir/ritonavir, younger age, vaccination, female gender and residence in a higher socioeconomic status area.

CONCLUSIONS

COVID-19 hospitalization risk was reduced by 84% among nirmatrelvir/ritonavir recipients in a large, diverse healthcare system during the Omicron wave. These results suggest that nirmatrelvir/ritonavir remained highly effective in a setting substantially different than the original clinical trials.

Clinical characteristics and treatment outcomes among the hospitalized elderly patients with COVID-19 during the late pandemic phase in central Taiwan

BACKGROUND

There is a lack of information regarding outcomes of elderly patients hospitalized with COVID-19 following the widespread use of COVID-19 vaccines and antiviral agents.

METHODS

A retrospective study was conducted between January and August 2022, enrolling patients aged 65 years or older. Patients were categorized into two groups: 'old' (65-79 years) and 'oldest-old' (80 years or more). Multivariate regression was employed to identify independent prognostic factors for in-hospital mortality.

RESULTS

A total of 797 patients were enrolled, including 428 old and 369 oldest-old patients. In each subgroup, 66.6 % and 59.6 % of patients received at least one dose of the COVID-19 vaccine, respectively. Approximately 40 % of the patients received oral antiviral agents either before or upon hospital admission. A greater percentage of the oldest-old patients received remdesivir (53.4 % versus 39.7 %, p < 0.001), dexamethasone (49.3 % versus 36.7 %, p < 0.001), and tocilizumab (10.0 % versus 6.8 %, p < 0.001) than old patients. The mortality rate was comparable between the two age subgroups (14 % versus 15.2 %). Independent predictors of in-hospital mortality included disease severity and comorbidities such as end-stage renal disease (ESRD), cirrhosis, solid tumours, and haematologic malignancies. Ageing was not correlated with increased in-hospital mortality across all comorbidity subgroups.

CONCLUSIONS

In the later stages of the pandemic, with widespread vaccination and advancements in COVID-19 treatments, outcomes for hospitalized elderly and oldest-old patients with COVID-19 have improved. The influence of age on in-hospital mortality has diminished, while comorbidities such as ESRD, cirrhosis, solid tumours, and hematologic malignancies have been associated with mortality.

Nirmatrelvir and ritonavir combination against COVID-19 caused by omicron BA.2.2 in the elderly: A single-center large observational study

BACKGROUND

Since coronavirus 2019 (COVID-19) swept the world, a variety of novel therapeutic and prevention strategies have been developed, among which nirmatrelvir-ritonavir is highly recommended. We intended to assess the effectiveness and safety of nirmatrelvir-ritonavir in the elderly mild-to-moderate COVID-19 population caused by the omicron BA.2.2 variant in real-world settings.

METHODS

An observational study was conducted retrospectively to review the outcomes of mild-to-moderate COVID-19 patients admitted between April 26 and June 30, 2022. Patients' baseline characteristics were collected and assessed. Participants in the intervention group were administered nirmatrelvir-ritonavir in addition to standard care, whereas those in the control group only received standard care. The primary outcome was the duration between the initial positive reverse-transcription polymerase chain reaction (RT-PCR) test and the subsequent conversion to a negative result.

RESULTS

The analysis included 324 patients who were administered nirmatrelvir-ritonavir and an equal number of control patients. The patient characteristics in both groups were evenly matched. The average duration from the initial positive RT-PCR to negative conversion was similar in both groups (16.2 ± 5.0 vs. 16.1 ± 6.3 days, p = .83). Control patients exhibited slower conversion in comparison to patients who received nirmatrelvir-ritonavir treatment within 10 days of symptom onset.

CONCLUSIONS

These findings suggest that administering nirmatrelvir-ritonavir within 10 days of symptom onset could potentially reduce the time it takes for SARS-CoV-2-infected patients to negative RT-PCR results, thereby expanding the current usage guidelines for nirmatrelvir-ritonavir.

Predictors of nirmatrelvir-ritonavir receipt among COVID-19 patients in a large US health system

A clear understanding of real-world uptake of nirmatrelvir-ritonavir for treatment of SARS-CoV-2 can inform treatment allocation strategies and improve interpretation of effectiveness studies. We used data from a large US healthcare system to describe nirmatrelvir-ritonavir dispenses among all SARS-CoV-2 positive patients aged ≥ 12 years meeting recommended National Institutes of Health treatment eligibility criteria for the study period between 1 January and 31 December, 2022. Overall, 10.9% (N = 34,791/319,900) of treatment eligible patients with SARS-CoV-2 infections received nirmatrelvir-ritonavir over the study period. Although uptake of nirmatrelvir-ritonavir increased over time, by the end of 2022, less than a quarter of treatment eligible patients with SARS-CoV-2 infections had received nirmatrelvir-ritonavir. Across patient demographics, treatment was generally consistent with tiered treatment guidelines, with dispenses concentrated among patients aged ≥ 65 years (14,706/63,921; 23.0%), and with multiple comorbidities (10,989/54,431; 20.1%). However, neighborhoods of lower socioeconomic status (upper third of neighborhood deprivation index [NDI]) had between 12% (95% CI: 7-18%) and 28% (25-32%) lower odds of treatment dispense over the time periods studied compared to the lower third of NDI distribution, even after accounting for demographic and clinical characteristics. A limited chart review (N = 40) confirmed that in some cases a decision not to treat was appropriate and aligned with national guidelines to use clinical judgement on a case-by-case basis. There is a need to enhance patient and provider awareness on the availability and benefits of nirmatrelvir-ritonavir for the treatment of COVID-19 illness.

Early administration of nirmatrelvir/ritonavir leads to faster negative SARS-CoV-2 nasal swabs than monoclonal antibodies in COVID 19 patients at high-risk for severe disease

PURPOSE

Besides the well-established efficacy in preventing severe COVID-19, the impact of early treatments, namely antivirals and monoclonal antibodies (mAbs), on the time length to negativization of SARS-CoV-2 nasal swabs is still unclear. The aim of this study was to compare the efficacy of different early treatments in reducing the SARS-CoV-2 viral shedding, identifying a single drug that might potentially lead to a more rapid negativization of SARS-CoV-2 nasal swab.

METHODS

This was a single-centre, retrospective, observational study conducted at Ospedale Luigi Sacco in Milan. Data of high-risk COVID-19 patients who received early treatments between 23 December 2021 and March 2023 were extracted. The comparison across treatments was conducted using the Kruskall-Wallis test for continuous variables. Dunn's test with Bonferroni adjustment was performed for post-hoc comparisons of days to negativization. Secondly, a negative binomial regression adjusted for age, sex, number of comorbidities, immunosuppression, and SARS-CoV-2 vaccination status was implemented.

RESULTS

Data from 428 patients receiving early treatments were collected. The majority were treated with Nirmatrelvir/Ritonavir and were affected by SARS-CoV-2 Omicron infection with BA.2 sublineage. The median length time to SARS-CoV-2 nasal swab negativization was 9 days [IQR 7-13 days]. We found that Nirmatrelvir/Ritonavir determined a significant decrease of the length time to SARS-CoV-2 nasal swab negativization compared to mAbs (p = 0.003), but not compared to Remdesivir (p = 0.147) and Molnupiravir (p = 0.156).

CONCLUSION

Our findings highlight the importance of promptly treating high-risk COVID-19 patients with Nirmatrelvir/Ritonavir, as it also contributes to achieving a faster time to negative SARS-CoV-2 nasal swabs.

Comparison of Bivalent and Monovalent mRNA Vaccine Boosters

In this cohort study conducted in Hong Kong where both bivalent and monovalent formulations of BNT162b2 were available, there were no significant differences in the mortality or hospitalization between those who received bivalent and monovalent mRNA as second boosters. Bivalent and monovalent mRNA boosters appear equally protective against clinical outcomes.

Physician characteristics associated with antiviral prescriptions for older adults with COVID-19 in Japan: an observational study

OBJECTIVES

Although guidelines recommend antiviral therapy for outpatients with COVID-19 who are at high risk of progressing to severe conditions, such as older adults, many patients do not receive appropriate treatment. Little is known, however, about the physician factors associated with the prescription of guideline-recommended antiviral therapy for patients with COVID-19.

DESIGN

A cross-sectional study.

SETTING

Data including outpatient visits in primary care clinics in Japan from April to August 2023.

PARTICIPANTS

We analysed 30 953 outpatients aged ≥65 years treated with COVID-19 (mean (SD) age, 75.0 (7.6) years; 17 652 women (57.0%)) in 1394 primary care clinics.

OUTCOME MEASURES

The primary outcome was the prescription of guideline-recommended antivirals (ie, nirmatrelvir-ritonavir or molnupiravir), adjusted for patient characteristics, months of visits and regions.

RESULTS

Antiviral prescriptions were concentrated among a small proportion of physicians; for example, the top 10% of physicians that had the largest number of nirmatrelvir-ritonavir prescriptions accounted for 92.4% of all nirmatrelvir-ritonavir prescriptions. After adjusting for potential confounders, physicians with higher patient volumes were more likely to prescribe guideline-recommended antivirals to their patients (adjusted OR (aOR) for high vs low volume, 1.76; 95% CI 1.31 to 2.38; adjusted p<0.001). We found no evidence that the likelihood of guideline-recommended antiviral prescription differed based on physicians' gender (aOR for women vs men, 1.24; 95% CI 0.88 to 1.74; adjusted p=0.48) or age (aOR for 45-59 vs <45 years, 1.16; 95% CI 0.87 to 1.54; adjusted p=0.48; aOR for ≥60 vs <45 years, 0.88; 95% CI 0.66 to 1.16; adjusted p=0.48). These patterns were similar when examining nirmatrelvir-ritonavir and molnupiravir separately.

CONCLUSIONS

Our findings suggest that provider-level factors, such as the clinical experience of treating the patients with COVID-19, play an important role in the appropriate prescription of antiviral medications for COVID-19 in the primary care setting.

Comparing Molnupiravir to Nirmatrelvir/Ritonavir (Paxlovid) in the Treatment of Mild-to-Moderate COVID-19 in Immunocompromised Cancer Patients

BACKGROUND

Nirmatrelvir/Ritonavir has been shown to reduce the risk of COVID-19 progression by 88% compared to placebo, while Molnupiravir reduced it by 31%. However, these two agents have not been compared head-to-head. We therefore compared the safety and efficacy of both agents for the treatment of mild-to-moderate COVID-19 in immunocompromised cancer patients.

METHODS

We identified 240 cancer patients diagnosed with COVID-19 and treated with Molnupiravir or Nirmatrelvir/Ritonavir. Patients were matched using a 1:2 ratio based on age group (18-64 years vs. ≥65) and type of cancer. The collected data included demographics, comorbidities, and treatment outcome.

RESULTS

Both groups had comparable characteristics and presenting symptoms. However, dyspnea was more prevalent in the Molnupiravir group, while sore throat was more prevalent in the Nirmatrelvir/Ritonavir group. The rate of disease progression was comparable in both groups by univariate and multivariable analysis. Treatment with Molnupiravir versus Nirmatrelvir/Ritonavir revealed no significant difference in disease progression by multivariable analysis (adjusted OR = 1.31, 95% CI: 0.56-3.14, p = 0.70). Patients who received Nirmatrelvir/Ritonavir, however, were significantly more prone to having drug-drug interactions/adverse events (30% vs. 0%, p < 0.0001).

CONCLUSIONS

In the treatment of mild-to-moderate COVID-19 in cancer patients, Molnupiravir was comparable to Nirmatrelvir/Ritonavir in preventing progression to severe disease/death and rebound events, and it had a superior safety profile.

Counterfactual analysis of the 2023 Omicron XBB wave in China

Background

China has experienced a COVID-19 wave caused by Omicron XBB variant starting in April 2023. Our aim is to conduct a retrospective analysis exploring the dynamics of the outbreak under counterfactual scenarios that combine the use of vaccines, antiviral drugs, and nonpharmaceutical interventions.

Methods

We developed a mathematical model of XBB transmission in China, which has been calibrated using SARS-CoV-2 positive rates per week. Intrinsic age-specific infection-hospitalization risk, infection-ICU risk, and infection-fatality risk were used to estimate disease burdens, characterized as number of hospital admissions, ICU admissions, and deaths.

Results

We estimated that in absence of behavioral change, the XBB outbreak in spring 2023 would have resulted in 0.86 billion infections (∼61% of the total population). Our counterfactual analysis shows that the synergetic effect of vaccination (70% vaccination coverage), antiviral treatment (20% receiving antiviral treatment), and moderate nonpharmaceutical interventions (20% isolation and L1 PHSMs) could reduce the number of deaths to levels close to seasonal influenza (1.17 vs. 0.65 per 10,000 individuals and 5.85 vs. 3.85 per 10,000 individuals aged 60+, respectively). The maximum peak prevalence of hospital and ICU admissions are estimated to be lower than the corresponding capacities (8.6 vs. 10.4 per 10,000 individuals and 1.2 vs. 2.1 per 10,000 individuals, respectively).

Conclusion

Our findings suggest that the capacity of the Chinese healthcare system was adequate to face the Omicron XBB wave in spring 2023 but, at the same time, supports the importance of administering highly effective vaccine with long-lasting immune response, and the use of antiviral treatments.

Effectiveness of mRNA BNT162b2 and inactivated CoronaVac vaccines against severe COVID-19 outcomes among non-hospitalised children aged 1-3 years with SARS-CoV-2 Omicron infection

OBJECTIVES

Clinical evidence on the effectiveness of COVID-19 vaccines for children aged 1-3 years is scarce. The effectiveness of COVID-19 vaccines was evaluated among non-hospitalised children aged 1-3 years with SARS-CoV-2 Omicron infection in Hong Kong.

METHODS

A retrospective cohort of all non-hospitalised children aged 1-3 years with confirmed SARS-CoV-2 infection between 4 August 2022 and 29 January 2023 in Hong Kong was analysed. Vaccinated group was defined as the recipients of one or more doses of CoronaVac or mRNA vaccine BNT162b2 (original, monovalent) at least 14 days prior to infection. Hazard ratios (HR) with 95% confidence intervals (95% CI) of study outcomes were estimated using Cox regression models. Effectiveness outcomes included 28-day all-cause mortality and COVID-19-related hospitalisation.

RESULTS

A total of 5552 vaccinated patients and 5552 propensity-score matched controls (unvaccinated patients) were included for analysis. The cumulative incidence of COVID-19-related hospitalisation over 28 days was 2.3% and 2.9% in the vaccinated and control groups, respectively. There were no deaths in both groups. COVID-19 vaccination was associated with a significant reduction in 28-day COVID-19-related hospitalisation risk (HR=0.785, 95% CI=0.626-0.985, P=0.037), particularly for children aged 3 years, those who had received two or more vaccine doses, and those who received CoronaVac as the last dose.

CONCLUSION

COVID-19 vaccination is associated with a significantly lower risk of 28-day COVID-19-related hospitalisation among infected children aged 1-3 years, particularly those who had received two or more vaccine doses. This observation emphasises the importance of completing the full two-dose or three-dose series to optimise vaccine effectiveness.

CT-based Assessment at 6-Month Follow-up of COVID-19 Pneumonia patients in China

This study aimed to assess pulmonary changes at 6-month follow-up CT and predictors of pulmonary residual abnormalities and fibrotic-like changes in COVID-19 pneumonia patients in China following relaxation of COVID restrictions in 2022. A total of 271 hospitalized patients with COVID-19 pneumonia admitted between November 29, 2022 and February 10, 2023 were prospectively evaluated at 6 months. CT characteristics and Chest CT scores of pulmonary abnormalities were compared between the initial and the 6-month CT. The association of demographic and clinical factors with CT residual abnormalities or fibrotic-like changes were assessed using logistic regression. Follow-up CT scans were obtained at a median of 177 days (IQR, 170-185 days) after hospital admission. Pulmonary residual abnormalities and fibrotic-like changes were found in 98 (36.2%) and 39 (14.4%) participants. In multivariable analysis of pulmonary residual abnormalities and fibrotic-like changes, the top three predictive factors were invasive ventilation (OR 13.6; 95% CI 1.9, 45; P < .001), age > 60 years (OR 9.1; 95% CI 2.3, 39; P = .01), paxlovid (OR 0.11; 95% CI 0.04, 0.48; P = .01) and invasive ventilation (OR 10.3; 95% CI 2.9, 33; P = .002), paxlovid (OR 0.1; 95% CI 0.03, 0.48; P = .01), smoker (OR 9.9; 95% CI 2.4, 31; P = .01), respectively. The 6-month follow-up CT of recent COVID-19 pneumonia cases in China showed a considerable proportion of the patients with pulmonary residual abnormalities and fibrotic-like changes. Antivirals against SARS-CoV-2 like paxlovid may be beneficial for long-term regression of COVID-19 pneumonia.

Effectiveness of azvudine in reducing mortality of COVID-19 patients: a systematic review and meta-analysis

BACKGROUND

Azvudine has been approved for the treatment of coronavirus disease 2019 (COVID-19) patients in China, and this meta-analysis aims to illustrate the safety of azvudine and its effectiveness in reducing mortality.

METHODS

PubMed, Embase, Web of science, Cochrane Library and the Epistemonikos COVID-19 Living Overview of Evidence database (L.OVE) were searched to aggregate currently published studies. Cochrane risk of bias tool and ROBINS-I tool were used to assess the risk of bias of randomized controlled study and cohort study respectively. Odds radios (ORs) with 95% confidence interval (CIs) were combined for dichotomous variables. Publication bias was assessed by Egger's test and funnel plots.

RESULTS

A total of 184 articles were retrieved from the included databases and 17 studies were included into the final analysis. Pooled analysis showed that azvudine significantly reduced mortality risk in COVID-19 patients compared with controls (OR: 0.41, 95%CI 0.31-0.54, p < 0.001). Besides, either mild to moderate or severe COVID-19 patients could benefit from azvudine administration. There was no significant difference in the incidence of ICU admission (OR: 0.90, 95%CI 0.47-1.72, p = 0.74) and invasive ventilation (OR: 0.94, 95%CI 0.54-1.62, p = 0.82) between azvudine and control group. The incidence of adverse events was similar between azvudine and control (OR: 1.26, 95%CI 0.59-2.70, p = 0.56).

CONCLUSIONS

This meta-analysis suggests that azvudine could reduce the mortality risk of COVID-19 patients, and the safety of administration is acceptable.

TRIAL REGISTRATION

PROSPERO; No.: CRD42023462988; URL: https://www.crd.york.ac.uk/prospero/ .

Determining and Comparing the Real-World Effectiveness of Molnupiravir and Nirmatrelvir-Ritonavir in Patients Hospitalized With COVID-19

BACKGROUND

Current guidelines recommend using nirmatrelvir-ritonavir for coronavirus disease 2019 (COVID-19) treatment, but its potential drug interactions and contraindications limit its applicability in certain categories of patients. The aim of the study was to evaluate the real-world effectiveness of molnupiravir and nirmatrelvir-ritonavir in managing COVID-19 among hospitalized patients.

METHODS

We conducted a retrospective cohort study among hospitalized COVID-19 patients who received molnupiravir or nirmatrelvir-ritonavir and did not require baseline supplemental oxygen from February 2022 to January 2023. We compared the effectiveness of molnupiravir and nirmatrelvir-ritonavir with a focus on disease progression.

RESULTS

The study included 401 high-risk, hospitalized adult COVID-19 patients who received molnupiravir or nirmatrelvir-ritonavir. No significant difference was found in disease progression, the composite outcome of disease progression (4.0% vs. 1.4%, P = 0.782), and O2 supplementation via nasal prong (21.8% vs. 14.8%, P = 0.115) between the patients treated with molnupiravir and those treated with nirmatrelvir-ritonavir. This finding was similar after 1:1 propensity-score matching. In the multivariate analysis, molnupiravir treatment was not significantly associated with progression to severe disease.

CONCLUSION

In conclusion, our findings suggest that similar to nirmatrelvir-ritonavir, molnupiravir has a distinct potential role in COVID-19 treatment, transcending its current perceived status as only a secondary option.

Molnupiravir: Mechanism of action, clinical, and translational science

Molnupiravir is an oral prodrug of the broadly active, antiviral ribonucleoside analog N-hydroxycytidine (NHC). The primary circulating metabolite NHC is taken up into cells and phosphorylated to NHC-triphosphate (NHC-TP). NHC-TP serves as a competitive substrate for viral RNA-dependent RNA polymerase (RdRp), which results in an accumulation of errors in the viral genome, rendering virus replication incompetent. Molnupiravir has demonstrated activity against SARS-CoV-2 both clinically and preclinically and has a high barrier to development of viral resistance. Little to no molnupiravir is observed in plasma due to rapid hydrolysis to NHC. Maximum concentrations of NHC are reached at 1.5 h following administration in a fasted state. The effective half-life of NHC is 3.3 h, reflecting minimal accumulation in the plasma following twice-daily (Q12H) dosing. The terminal half-life of NHC is 20.6 h. NHC-TP exhibits a flatter profile with a lower peak-to-trough ratio compared with NHC, which supports Q12H dosing. Renal and hepatic pathways are not major routes of elimination, as NHC is primarily cleared by metabolism to uridine and cytidine, which then mix with the endogenous nucleotide pools. In a phase III study of nonhospitalized patients with COVID-19 (MOVe-OUT), 5 days of treatment with 800 mg molnupiravir Q12H significantly reduced the incidence of hospitalization or death compared with placebo. Patients treated with molnupiravir also had a greater reduction in SARS-CoV-2 viral load and improved clinical outcomes, compared with those receiving placebo. The clinical effectiveness of molnupiravir has been further demonstrated in several real-world evidence studies. Molnupiravir is currently authorized or approved in more than 25 countries.

COVID-19: On the threshold of the fifth year. The situation in Spain

Despite having emerged from pandemic status, the incidence of COVID-19 episodes has recently increased in Spain, including pediatric cases and admissions to Intensive Care Units. Several recombinant variants are circulating among us, particularly XBB arising from two Omicron BA.2 sublineages with mutations in the genes encoding the spicule proteins that could increase binding to the ACE2 receptor and be more prone to immune escape. Faced with these, 3 pharmaceutical companies have developed vaccines adapted to the XBB.1.5 sublineage that are already available for administration in our setting with risks that should not be different from those of previous mRNA vaccines and with clearly favorable benefit/risk ratios. They should be applied to patients with potential for poor COVID-19 evolution and to collectives that have a particular relationship of proximity with them. Their application should be understood not only from a perspective of individual convenience but also from that of collective responsibility. The most convenient seems to be a simultaneous immunization of COVID-19 and influenza in our environment. In the therapeutic aspect, there is little to expect right now from antisera, but the already known antiviral drugs are still available and indicated, although their efficacy will have to be reevaluated due to their impact on populations that are mostly immunized and with a better prognosis than in the past. In our opinion, it is necessary to continue to make a reasonable and timely use of masks and other non-pharmacological means of protection.

Effectiveness of nirmatrelvir-ritonavir on severe outcomes of COVID-19 in the era of vaccination and Omicron: An updated meta-analysis

Nirmatrelvir-ritonavir (NR) was approved to treat SARS-CoV-2 positive outpatients at high risk of progression to severe disease, based on a randomized trial in unvaccinated patients. Effectiveness in vaccinated patients and against Omicron has not yet been confirmed by clinical trial data, but a recent meta-analysis suggested good real-world effectiveness based on 12 studies. We updated this meta-analysis by searching Medline and Embase databases for studies assessing effectiveness of NR on mortality, hospitalization, composite outcome of hospitalization and/or death, and progression to severe disease, published between October 1, 2022 and May 22, 2023. Random effects meta-analysis and subgroup analysis for vaccinated patients was performed. A total of 32 studies were included in the meta-analysis. Pooled RR for the effect of NR on mortality, hospitalization, hospitalization and/or mortality, and progression to severe disease were 0.36 (95% confidence interval [CI]: 0.25-0.52), 0.43 (CI: 0.37-0.51), 0.52 (CI: 0.45-0.61) and 0.54 (CI: 0.41-0.73), respectively. A subgroup analysis on vaccinated patients indicated lower effectiveness of NR on mortality (RR: 0.55, CI: 0.45-0.68), but similar effectiveness for hospitalization, hospitalization and/or mortality, or progression to severe disease (RR: 0.52, 0.58, and 0.66, respectively). This updated meta-analysis robustly confirms the protective effects of NR on severe COVID-19 outcomes.

Oral Simnotrelvir for Adult Patients with Mild-to-Moderate Covid-19

BACKGROUND

Simnotrelvir is an oral 3-chymotrypsin-like protease inhibitor that has been found to have in vitro activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and potential efficacy in a phase 1B trial.

METHODS

In this phase 2-3, double-blind, randomized, placebo-controlled trial, we assigned patients who had mild-to-moderate coronavirus disease 2019 (Covid-19) and onset of symptoms within the past 3 days in a 1:1 ratio to receive 750 mg of simnotrelvir plus 100 mg of ritonavir or placebo twice daily for 5 days. The primary efficacy end point was the time to sustained resolution of symptoms, defined as the absence of 11 Covid-19-related symptoms for 2 consecutive days. Safety and changes in viral load were also assessed.

RESULTS

A total of 1208 patients were enrolled at 35 sites in China; 603 were assigned to receive simnotrelvir and 605 to receive placebo. Among patients in the modified intention-to-treat population who received the first dose of trial drug or placebo within 72 hours after symptom onset, the time to sustained resolution of Covid-19 symptoms was significantly shorter in the simnotrelvir group than in the placebo group (180.1 hours [95% confidence interval {CI}, 162.1 to 201.6] vs. 216.0 hours [95% CI, 203.4 to 228.1]; median difference, -35.8 hours [95% CI, -60.1 to -12.4]; P = 0.006 by Peto-Prentice test). On day 5, the decrease in viral load from baseline was greater in the simnotrelvir group than in the placebo group (mean difference [±SE], -1.51±0.14 log10 copies per milliliter; 95% CI, -1.79 to -1.24). The incidence of adverse events during treatment was higher in the simnotrelvir group than in the placebo group (29.0% vs. 21.6%). Most adverse events were mild or moderate.

CONCLUSIONS

Early administration of simnotrelvir plus ritonavir shortened the time to the resolution of symptoms among adult patients with Covid-19, without evident safety concerns. (Funded by Jiangsu Simcere Pharmaceutical; ClinicalTrials.gov number, NCT05506176.).

Exploring Paxlovid Efficacy in COVID-19 Patients with MAFLD: Insights from a Single-Center Prospective Cohort Study

This study investigates the intricate interplay between Metabolic-associated Fatty Liver Disease (MAFLD) and COVID-19, exploring the impact of MAFLD on disease severity, outcomes, and the efficacy of the antiviral agent Paxlovid (nirmatrelvir/ritonavir). MAFLD, affecting a quarter of the global population, emerges as a potential risk factor for severe COVID-19, yet the underlying pathophysiological mechanisms remain elusive. This study focuses on the clinical significance of Paxlovid, the first orally bioavailable antiviral agent granted Emergency Use Authorization in the United States. Notably, outcomes from phase II/III trials exhibit an 88% relative risk reduction in COVID-19-associated hospitalization or mortality among high-risk patients. Despite conflicting data on the association between MAFLD and COVID-19 severity, this research strives to bridge the gap by evaluating the effectiveness of Paxlovid in MAFLD patients with COVID-19, addressing the scarcity of relevant studies.

Real-World Effectiveness Study of Nirmatrelvir-Ritonavir or Molnupiravir in Hospitalized Unvaccinated Patients with Chronic Respiratory Diseases and Moderate COVID-19 at Presentation

Introduction

Nirmatrelvir-ritonavir (NMV-r) and molnupiravir (MOL) were developed as out-patient anti-viral for mild COVID-19. There was limited data on their role in treating COVID-19 for hospitalized patients, especially among adult patients who are unvaccinated and had chronic respiratory diseases.

Methods

A territory-wide retrospective study was conducted in Hong Kong to compare the efficacy of NMV-r and MOL against COVID-19 in unvaccinated adult patients with asthma, chronic obstructive pulmonary disease, bronchiectasis and interstitial lung diseases presenting with moderate COVID-19 from 16th February 2022 to 15th March 2023.

Results

A total of 1354 patients were included, 738 received NMV-r and 616 received MOL. NMV-r was more effective in reducing 90-day mortality with adjusted hazard ratios (aHR) of 0.508 (95% confidence interval [CI] = 0.314-0.822, p = 0.006). Patients who received NMV-r also had significantly shorter length of stay (LOS) than those receiving MOL, with median LOS of 4 (Interquartile range [IQR] = 2-7) for NMV-r and 6 (IQR = 3-10) for MOL (p-value < 0.001). There was no statistically significant difference in the development of respiratory failure and severe respiratory failure in the two groups.

Discussion

NMV-r was more effective than MOL among unvaccinated adults with chronic respiratory diseases who were hospitalized for moderate COVID-19 without hypoxaemia on admission.

Simultaneous quantification of nirmatrelvir/ritonavir in human serum by LC-HRMS

In December 2021, the U.S. Food and Drug Administration (FDA) granted emergency authorization for Paxlovid® as an antiviral treatment for COVID-19. Paxlovid® is composed of two tablets, nirmatrelvir and ritonavir. Dose adjustment is necessary in cases of renal insufficiency. The aim of present study is to establish a LC-HRMS method for simultaneous determination of nirmatrelvir/ritonavir in human serum for therapeutic drug monitoring. Internal standard saquinavir was added in 25 μL human serum samples, and then the samples were precipitated with methanol. The analytes were separated by gradient elution on a C18 column, using a mobile phase of 0.1 % formic acid-water and methanol, at a flow rate of 0.4 mL/min. The injection volume was 2 μL, and the analysis time was 5 min. The determination of the analytes was performed by electrospray ionization in positive mode by full mass monitoring. The detected ions of nirmatrelvir, ritonavir and saquinavir were m/z 500.24792, 721.32004 and 671.39155, respectively. The linear concentration range for nirmatrelvir was 78.13-20000 ng mL-1, for ritonavir was 15.63-4000 ng mL-1 (r2＞0.9900). The accuracy ranged from 87.45 %∼104.63 %, and the intra-day and inter-day precision RSD was <15 %. The recovery of nirmatrelvir ranged from 98.72 %∼109.83 %, and that of ritonavir was 95.41∼112.36 %. The matrix effect of nirmatrelvir was 88.31∼97.73 %, and that of ritonavir was 85.17∼103.05 %. This method was used to measure the trough concentrations of nirmatrelvir/ritonavir in 17 patients. The trough concentration of nirmatrelvir was 1331.7-8352.5 ng/mL, and that of ritonavir was 53.4-1325.5 ng mL-1, with large individual differences. The method is simple, sensitive, specific, and reproducible, and can be used for monitoring the blood concentration and pharmacokinetic study of nirmatrelvir/ritonavir in COVID-19 patients.

Retrospective Cohort Study on Determinants of Mechanical Ventilation Duration of COVID-19 ICU Patients

Background In the face of the ongoing global health crisis posed by COVID-19, it becomes imperative to understand the disease's dynamics, particularly in specific regions. This study provides a detailed examination of the factors influencing mechanical ventilation (MV) duration among COVID-19 patients in an intensive care setting, focusing on a diverse patient cohort from the Al Hassa region of Saudi Arabia. The primary aim of this study was to identify key demographic factors, clinical outcomes, and comorbidities that affect the duration of MV among ICU patients with COVID-19. This understanding is crucial for enhancing patient care and informing healthcare strategies in the context of the pandemic. Methods A retrospective cohort study was conducted involving patients diagnosed with COVID-19 and admitted to the ICU in the Al Hassa region. The total number of participants was 1,259. Using a systematic sampling method, these participants were chosen to create a representative sample that reflects the prevailing treatment protocols in ICUs across these hospitals. Data encompassed patient demographics, comorbidities, clinical outcomes, and MV duration. Statistical analyses were employed to explore the associations between these variables. Results Our findings reveal a total of 1,259 participants significant associations between MV duration and various factors, including nationality, legal status, travel history, and comorbidities like heart failure and immunocompromised status. These insights are instrumental in understanding the nuances of COVID-19 management in critical care. Conclusion The study provides valuable insights into the determinants of MV duration in severe COVID-19 cases, emphasizing the need for individualized patient care approaches. It highlights the complexity of managing COVID-19 in ICU settings and underscores the importance of tailored healthcare responses to this global health challenge, particularly in the Al Hassa region.

Efficacy and safety of antiviral treatments for symptomatic COVID-19 outpatients: Systematic review and network meta-analysis

BACKGROUND

Remdesivir, molnupiravir, and nirmatrelvir/ritonavir are three antiviral agents approved by FDA emergency authorization for treating mild to moderate symptomatic COVID-19 adult outpatients at high risk for hospitalization and death.

OBJECTIVES

To compare the efficacy and safety of these antivirals based on updated published RCT and real-world data.

STUDY DESIGN

This systematic review followed the preferred reporting items for systematic reviews and meta-analysis framework guidelines. We searched all publications up to January 2023. RRs and 95% CIs for death, hospitalization, and adverse events were calculated.

RESULTS

Six RCTs and seven cohort studies were included, with 1,456,523 participants, of whom 50,979 were treated with antivirals. Remdesivir was associated with the lowest probability of hospitalization and death compared to nirmatrelvir/ritonavir and molnupiravir (P-scores 0.99 and 0.90, respectively, for remdesivir, 0.64 and 0.55, respectively for nirmatrelvir/ritonavir, and 0.26 and 0.49, respectively for molnupiravir). Based on indirect comparisons, remdesivir was associated with a statistically significant decreased risk for hospitalization compared to molnupiravir (RR 0.09; 95% CI 0.02-0.40) and to nirmatrelvir/ritonavir (RR 0.11; 95% CI 0.03-0.73). No statistically significant difference was found between antivirals in the mortality risk reduction and the risk for side effects.

CONCLUSIONS

This is the most comprehensive network meta-analysis integrating RCTs and real-world data. In our indirect comparison, remdesivir was associated with the highest efficacy in preventing hospitalization among high risk symptomatic COVID-19 outpatients, compared to nirmatrelvir/ritonavir and molnupiravir. This finding supports current guidelines, and may have importance when deciding which antiviral to use, together with other important factors.

Antiviral therapy of coronavirus disease 2019 (COVID-19)

The coronavirus disease 2019 (COVID-19) pandemic has reached a turning point. The non-pharmaceutical interventions for preventing COVID-19 are lifting. Vaccination uptake is increasing in general, but this strategy is continuously challenged by the rapid evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Of note, the Omicron subvariants spread globally for at least one year, and the most recently developed subvariants show strong immune evasion to preexisting immunity, either from previous infection, vaccination or both. Therefore, early and appropriate antiviral agents to treat patients at risk for severe COVID-19 or death is crucial to decrease morbidities and mortalities, to restore the healthcare capacities and to facilitate a return to the new normal. Current antiviral therapy for COVID-19 consist of neutralizing monoclonal antibodies (mAbs) and direct antiviral agents. Each agent has been proved for early ambulatory treatment of COIVD-19, but suffer from variable effectiveness and limitations due to patients' comorbidities, drug properties, or antiviral resistance. Besides, some specific mAbs are indicated for prophylaxis of COVID-19 before or after close contact with confirmed COVID-19 patients. This review article summarizes the evidence and unmet needs of the currently available antiviral agents for management of COVID-19 in the context of the Omicron subvariants.

Effectiveness of Vaccines and Antiviral Drugs in Preventing Severe and Fatal COVID-19, Hong Kong

We compared the effectiveness and interactions of molnupiravir and nirmatrelvir/ritonavir and 2 vaccines, CoronaVac and Comirnaty, in a large population of inpatients with COVID-19 in Hong Kong. Both the oral antiviral drugs and vaccines were associated with lower risks for all-cause mortality and progression to serious/critical/fatal conditions (study outcomes). No significant interaction effects were observed between the antiviral drugs and vaccinations; their joint effects were additive. If antiviral drugs were prescribed within 5 days of confirmed COVID-19 diagnosis, usage was associated with lower risks for the target outcomes for patients >60, but not <60, years of age; no significant clinical benefit was found if prescribed beyond 5 days. Among patients >80 years of age, 3-4 doses of Comirnaty vaccine were associated with significantly lower risks for target outcomes. Policies should encourage COVID-19 vaccination, and oral antivirals should be made accessible to infected persons within 5 days of confirmed diagnosis.