Estimates of SARS-CoV-2 Omicron Variant Severity in Ontario, Canada

SARS-CoV-2 test sensitivity and duration of positivity in the UK during the 2023/2024 Winter: A prospective cohort study based on self-reported data

Estimating epidemiological parameters is essential for informing an effective public health response during waves of infectious disease transmission. However, many parameters are challenging to estimate from real-world data and rely on human challenge studies or mass community testing. During Winter 2023/2024, a community cohort study of SARS-CoV-2 was conducted across households in England and Scotland. From this survey, questionnaire data and follow-up testing protocols provided valuable data on the duration of positivity and test sensitivity for lateral flow device (LFD) tests. Here, Bayesian statistical modelling methods are developed and applied to estimate the underlying parameters. The duration of LFD positivity is found to increase with increasing age, with a mean of 9.1 days (95% CrI: 8.4 days, 9.9 days) in the 18 to 34 years age group compared to 10.8 days (95% CrI: 10.3 days, 11.3 days) in the 75 years and over age group. Sex is found to have no impact on the duration of positivity. LFD test sensitivity at the time of symptom onset is very high, with an estimated sensitivity of 95% (95% CrI: 92%, 98%) across all age groups. As a function of time since symptom onset, LFD test sensitivity decays fastest in the youngest age group, reaching a minimum sensitivity of 0.26 (95% CrI: 0.16, 0.37) compared to 0.53 (95% CrI: 0.46, 0.6). Such patterns are expected since younger individuals experience less severe symptoms of COVID-19 and are likely to clear the virus faster. Females are found to have a slightly faster rate at which sensitivity decreases, but the same minimum sensitivity as Males. Combining the duration of positivity and test sensitivity distributions, we estimate the probability of returning a positive LFD test. Close to the symptom onset date, this probability is approximately 95%. However, this rapidly drops off, dropping below 5% after 13.8 days (95% CrI: 11.0 days, 17.3 days) for the youngest age group (3 to 17 years) and 17.8 days (95% CrI: 16.6 days, 19.2 days) for the 75 years and over age group. Although the probability of returning a positive LFD test rapidly drops off, it remains very high close to the time of symptom onset, which is when individuals are expected to be the most infectious.

Outcomes Associated with the use of High Dose Corticosteroids and IL-6 Inhibitors for the Treatment of Acute Respiratory Distress Syndrome Secondary to SARS COV-2

Background: During the COVID-19 pandemic, treatment strategies evolved rapidly. The RECOVERY trial established corticosteroids as the standard care for reducing mortality in COVID-19 patients. However, some critical care clinicians began using doses higher than those recommended in RECOVERY. Objective: To characterize the use of high-dose corticosteroids and IL-6 inhibitors in critically ill COVID-19 patients and examine their association with adverse drug events (ADEs). Methods: A retrospective cohort study of 320 electronic health records (January 1, 2020 - June 30, 2022) was conducted on COVID-19 patients requiring high-flow oxygen or mechanical ventilation. Patients were categorized based on corticosteroid dose: "high dose dexamethasone" (daily dose greater than 12 mg and/or for longer than 10 days), "low dose dexamethasone" (daily dose 12 mg or less for 10 days or less), and "no dexamethasone" (no corticosteroid therapy). Subgroups were created based on IL-6 inhibitor use. Results: High-dose dexamethasone was associated with increased odds of ADEs compared to low dose (OR 2.55, 95% CI 1.45 to 4.49) and no dexamethasone (OR 6.29, 95% CI 2.08 to 19.03). No additional efficacy benefit was observed in patients receiving high dose corticosteroids when compared to low dose corticosteroids. Patients receiving both an IL-6 inhibitor and high-dose dexamethasone had further increased odds of ADEs. High-dose dexamethasone was also associated with increased mortality compared to low dose (OR 3.78, 95% CI 1.97-7.25) and no dexamethasone (OR 15.22, 95% CI 3.27-70.74). Conclusions: Acknowledging the risk for residual confounding, higher doses of dexamethasone were associated with increased ADEs and mortality. These findings highlight the need for careful consideration of the use of high-dose dexamethasone.

Extracorporeal Membrane Oxygenation for COVID-19 During the Delta and Omicron Waves in North America

Clinical outcomes for patients with severe acute respiratory failure caused by different variants of the coronavirus disease 2019 (COVID-19) supported with extracorporeal membrane oxygenation (ECMO) are incompletely understood. Clinical characteristics, pre-ECMO management, and hospital mortality at 90 days for adults with COVID-19 who received venovenous ECMO (VV-ECMO) at North American centers during waves predominated by Delta (August 16 to December 12, 2021) and Omicron (January 31 to May 31, 2022) severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants were compared in a competing risks framework. One thousand seven hundred and sixty-six patients (1,580 Delta, 186 Omicron) received VV-ECMO for COVID-19 during the Delta- and Omicron-predominant waves in North American centers. In the unadjusted competing risks model, no significant difference was observed in risk of hospital mortality at 90 days between patients during the Delta- versus Omicron-predominant wave (subhazard ratio [sHR], 0.94; 95% confidence interval [CI], 0.74-1.19), but patients supported with VV-ECMO during the Omicron-predominant wave had a significantly lower adjusted risk of hospital mortality at 90 days (subhazard ratio, 0.71; 95% CI, 0.51-0.99). Patients receiving VV-ECMO during the Omicron-predominant wave had a similar unadjusted risk of hospital mortality at 90 days, but a significantly lower adjusted risk of hospital mortality at 90 days than those receiving VV-ECMO during the Delta-predominant wave.

In-hospital mortality in patients admitted to Australian intensive care units with COVID-19 between 2020 and 2024

Objective

To describe and compare the demographics, management, and outcomes for patients with COVID-19 admitted to intensive care units (ICUs) in Australia across the various waves of the COVID pandemic.

Design setting and participants

People aged ≥16 years who were admitted to a participating ICU with confirmed COVID-19 in the Short Period Incidence Study of Severe Acute Respiratory Infection (SPRINT-SARI) Australia study between February 2020 and May 2024.

Main outcome measures

Primary outcome: In-hospital mortality. Secondary outcomes: ICU mortality; ICU and hospital lengths of stay; supportive and disease-specific therapies.

Results

From 27 February 2020 to 18 May 2024, 10171 people were admitted to 72 ICUs with confirmed COVID-19 disease. The Wild Type wave included 518 (5.1%) patients, the Delta wave 2467 (24.3%) patients, and the Omicron wave 7186 (70.7%) patients. The median (IQR) age was 61 (49-70) years, 54 (41-66) years, and 65 (45-75) years, respectively (P < 0.001). The proportion of vaccinated cases increased in successive waves (1% vs 23.9% vs 65.1%) but plateaued in the Omicron subvariant waves (range 60.0%-71.9%). Invasive mechanical ventilation use decreased across successive waves (52.5% vs 43.6% vs 31.7%, P < 0.001). Use of extracorporeal membrane oxygenation was highest during the Delta wave (3.6%, 83 patients, median duration 18 days [IQR 9.8-35]). Multivariable analysis demonstrated an increased risk of in-hospital mortality among patients admitted during the Delta (adjusted HR 1.80, 95% CI: 1.38-2.35, p < 0.001) and Omicron (adjusted HR 1.88, 95% CI: 1.46-2.42, p < 0.001) waves when compared to the Wild Type wave.

Conclusion

COVID-19 continues to manifest significant morbidity and mortality in those requiring ICU admission. Despite a reduced need for ICU level supports, patients admitted during the Omicron wave demonstrated the highest in-hospital mortality.

Molnupiravir for high-risk adults with COVID-19: Target trial emulation in a Japanese cohort

BACKGROUND

Evidence on the effectiveness of molnupiravir for high-risk adults in a highly vaccinated Asian population is sparse. In this study, we aimed to estimate the association between molnupiravir use and hospital admission or death in high-risk adults with COVID-19 during the Omicron era.

METHODS

This retrospective cohort study included high-risk patients diagnosed with COVID-19 in Shimonoseki City between September 16, 2022, and May 8, 2023. The outcome was a composite of hospital admission or death within 28 days. Participants were categorized into two groups: those who used molnupiravir within 5 days of diagnosis and those who did not. The outcomes were compared using a Cox proportional hazards model. Treatment weighting was used to balance patient backgrounds between the groups, and the clone method with inverse probability of censoring weighting was used to adjust for informative censoring.

RESULTS

We analyzed 330 patients (190 females, 57.6 %) with a mean age of 68.6 years. The proportion of fully vaccinated and boosted patients was 82.9 % (155/187) in the molnupiravir group and 90.2 % (129/143) in the control group. The overall 28-day incidence of all-cause hospitalization and mortality was 5.2 % (17/330), with 3.2 % (6/187) in the molnupiravir group and 7.7 % (11/143) in the control group. Molnupiravir was associated with a decrease in hospital admissions or death within 28 days (weighted hazard ratio, 0.35 [95 % confidence intervals, 0.13 to 0.90]).

CONCLUSIONS

Molnupiravir was linked to fewer hospitalizations or deaths within 28 days compared to no treatment in highly vaccinated high-risk patients with COVID-19 in Japan.

Severe COVID-19 disease is associated with genetic factors affecting plasma ACE2 receptor and CRP concentrations

A hyperinflammatory state with highly elevated concentrations of inflammatory biomarkers such as C-reactive protein (CRP) is a characteristic feature of severe coronavirus disease 2019 (COVID-19). To examine a potential role of common genetic factors that may influence COVID-19 outcomes, we investigated whether individuals with a polygenic predisposition for a pro-inflammatory response (in the form of Polygenic Scores) are more likely to develop severe COVID-19. The innovative approach of polygenic scores to investigate genetic factors in COVID-19 severity should provide a comprehensive approach beyond single-gene studies. In our cohort of 156 patients of European ancestry, two overlapping Polygenic Scores (PGS) predicting a genetic predisposition to basal CRP concentrations were significantly different between non-severe and severe COVID-19 cases and were associated with less severe COVID-19 outcomes. Furthermore, specific single nucleotide polymorphisms (SNPs) that contribute to either of the two Polygenic Scores predicting basal CRP levels are associated with different traits that represent risk factors for COVID-19 disease initiation (ACE2 receptor, viral replication) and progression (CRP). We suggest that genetically determined enforced CRP formation may contribute to strengthening of innate immune responses and better initial pathogen control thereby reducing the risk of subsequent hyperinflammation and adverse course of COVID-19.

COVID-19 vaccine effectiveness against severe omicron-related outcomes in children aged 5 to 11 years in Ontario: A Canadian immunization research network (CIRN) study

BACKGROUND

Understanding how the efficacy of COVID-19 vaccines translates from clinical trials to real-world settings is critical to inform evolving vaccination policies. The objective of this study was to assess COVID-19 vaccine effectiveness (VE) against severe COVID-19-related outcomes in children aged 5-11 years, including COVID-19-related hospital admissions and multisystem inflammatory syndrome in children (MIS-C).

METHODS

We conducted a retrospective, population-based cohort study using linked health administrative data in the first year following the emergence of the Omicron variant (January 2 to December 31, 2022) in Ontario, Canada. Baseline differences between subgroups of interest were compared using standardized differences. We used multivariable Cox proportional hazard regression models to estimate VE by time since last vaccine dose by treating vaccination as a time-varying exposure, compared to unvaccinated children.

RESULTS

We included a total of 1,058,740 children, of which 583,867 (55.1 %) had received at least one vaccine dose by the end of the study period. In total, there were 185 COVID-19-related hospital admissions and 39 cases of MIS-C. The rate of COVID-19-related admission was substantially higher in children with an underlying comorbid condition compared to children who were previously healthy (adjusted hazard ratio [aHR] = 4.77, 95 %CI, 3.56-6.38). VE against COVID-19-related admission ranged from 93 % (95 %CI, 52-99 %) 7-29 days after a second dose to 63 % (95 %CI; 41-77 %) ≥120 days after a second dose. There was no statistically significant difference in the rate of MIS-C in children who received at least one dose of the vaccine compared to unvaccinated children (aHR = 0.71; 95 %CI, 0.38-1.34).

CONCLUSIONS

We found that, for children aged 5-11 years, VE against COVID-19-related hospitalization was high in the first four months after a second dose. Children with comorbid conditions were found to be at much higher risk of COVID-19-related severe outcomes and thus may benefit most from COVID-19 vaccination.

Real-world assessment of reinfection with SARS-CoV-2: Implications for vaccines

BACKGROUND

There have been over 670 million confirmed cases of SARS-CoV-2 infection globally, resulting in over 6.87 million deaths. With approximately 0.1 %-6.8 % experiencing reinfection. This retrospective cohort study aimed to compare the risk of short-term circulatory and respiratory sequelae between SARS-CoV-2 reinfection and initial infection, and assess the impact of vaccination.

METHOD

Data from the TriNetX US Collaborative network (2020-2022) were used to create two cohorts based on reinfection status. The main outcome assessed were medical utilization, circulatory and respiratory symptoms, and circulatory and respiratory diseases. The Kaplan-Meier method was used to compare the risks between two cohorts. Four subgroup analyses (vaccination status, age, sex, race) and six sensitivity analyses (rigorous definition, modified exclusion criteria, treatment, different COVID-19 variants timeline, address survivorship bias, and E-value calculation) were also conducted.

RESULTS

The reinfection cohort showed a significant reduction in medical utilization [ Hazard ratio, HR: 0.867, (95 % confidence interval, CI:0.839-0.896) for hospitalization, 0.488 (0.418-0.570) for critical care services, and 0.476 (0.360-0.629) for mechanical ventilation], lower risk of circulatory diseases [ HR: 0.701 (95 % CI:0.637-0.772), 0.695 (0.583-0.829), 0.660 (0.605-0.719), 0.741 (0.644-0.854), 0.614 (0.535-0.705), and 0.758 (0.656-0.876) for ischemic heart disease, inflammatory heart disease, dysrhythmias, venous thromboembolism, other cardiac disorders, and cerebrovascular diseases, respectively], and lower risk of respiratory diseases such as pneumonia, other acute lower respiratory infections, asthma, and hypoxemia [HR: 0.302 (95 % CI: 0.273-0.333), 0.811 (0.686-0.958), 0.791 (0.735-0.850), and 0.392 (0.338-0.455), respectively]. The vaccinated reinfection cohort showed no significant differences in medical utilization, circulatory diseases, or respiratory conditions but had a higher risk of breathing abnormalities. breathing abnormalities [HR: 1.195 (95 % CI:1.087-1.313)].

CONCLUSIONS

The individuals who experienced reinfection exhibited milder short-term sequelae in the circulatory and respiratory systems. Vaccine administration protects against cardiovascular or respiratory systems.

Effectiveness of COVID-19 vaccines against SARS-CoV-2 infection and severe outcomes in adults: a systematic review and meta-analysis of European studies published up to 22 January 2024

BACKGROUND

Up-to-date evidence from European studies on long-term vaccine effectiveness (VE) of COVID-19 vaccines is lacking. This review aimed to evaluate effectiveness and durability of primary vaccine series and boosters in preventing infection and severe outcomes in the European population.

METHODS

We conducted systematic searches of PubMed and Embase up to 22 January 2024. We included observational studies that evaluated VE against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or severe disease (hospitalisation, intensive care unit admission or death) for primary series and boosters in Europe. We applied a random-effects meta-analysis model.

RESULTS

We included 33 studies and over 56 million participants. The overall VE of the complete primary series against infection with any SARS-CoV-2 variant was 70.7%. VE was lower for Omicron, at 26.1%, than for pre-Omicron strains, at 77.0%. Over time, VE against infection by any variant decreased from 68.9% to 38.9% after 6 months. Boosters restored VE to 76.4% and maintained at 58.4% after 3 months. The overall VE of a complete primary series for severe outcomes due to any variant was 87.4%, with 93.3% for pre-Omicron and 62.8% for Omicron strains. Protection against severe outcomes declined less than for infection. 6 months after the primary series, the vaccine still provided over 50% protection against severe outcomes caused by Omicron. Boosters restored VE to 87.9% and maintained at 78.5% after 3 months.

CONCLUSION

VE against SARS-CoV-2 infection declines markedly with time and Omicron variants. Protection against severe outcomes was more durable and resistant to viral mutation. Boosters restored protection, emphasising the need for timely booster vaccination for vulnerable populations.

Cardiac Damage in Patients Infected with Different SARS-CoV-2 Variants of Concern

Coronavirus Disease 2019 causes significant morbidity, and different variants of concern (VOCs) can impact organ systems differently. We conducted a single-center retrospective cohort analysis comparing biomarkers and clinical outcomes in hospitalized patients infected with the wild-type or Alpha (wt/Alpha) VOC against patients infected with the Omicron VOC. We included 428 patients infected with the wt/Alpha VOC and 117 patients infected with the Omicron VOC. The Omicron cohort had higher maximal median high-sensitivity Troponin-T (hs-TnT) levels (wt/Alpha: 12.8 ng/L, IQR 6.6-29.5 vs. Omicron: 27.8 ng/L, IQR 13.7-54.0; p < 0.001) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) (wt/Alpha: 256 ng/L, IQR 74.5-913.5 vs. Omicron: 825 ng/L, IQR 168-2759; p < 0.001) levels. This remained true for patients under 65 years of age and without pre-existing cardiovascular disease (hs-TnT (wt/Alpha: 6.1 ng/L, IQR 2.5-10.25 vs. Omicron: 8.6 ng/L, IQR 6.2-15.7; p = 0.007) and NT-proBNP (wt/Alpha: 63 ng/L, IQR 25-223.75 vs. Omicron: 158 ng/L, IQR 75.5-299.5; p = 0.006)). In-hospital mortality was similar between the two groups (wt/Alpha: 53 or 12.7% vs. Omicron: 9 or 7.7%; p = 0.132) and more patients infected with wt/Alpha VOC required intensive care admission (wt/Alpha: 93 or 22.2% vs. Omicron: 14 or 12%; p = 0.014). Increased cardiac biomarkers were correlated with a higher risk of mortality and ICU admission in both groups. Herein, we detected higher levels of cardiac biomarkers in hospitalized patients infected with the Omicron VOC when compared to wt/Alpha, being indicative of higher cardiac involvement. Although hs-TnT and NT-proBNP levels were higher in the Omicron cohort and both markers were linked to in hospital mortality in both groups, the mortality rates were similar.

Vulnerability: An Interpretive Descriptive Study of Personal Support Workers' Experiences of Working During the COVID-19 Pandemic in Ontario, Canada

BACKGROUND/OBJECTIVES

Personal support workers (PSWs) are important healthcare workers providing essential services to thousands of Canadians. PSWs face many challenges that were exacerbated in the context of the COVID-19 pandemic. In this study we explore experiences of PSWs working through the pandemic in Ontario long-term care (LTC) homes by focusing on the vulnerability of such workers.

METHODS

An interpretive description approach was adopted. Eleven PSWs working in LTC homes in an urban center in Ontario participated in semi-structured interviews between January and May 2022. Thematic analysis of the transcripts was informed by concepts of vulnerability.

RESULTS

The results suggest that PSWs experienced inherent, situational, and pathogenic vulnerability. Inherent vulnerability was experienced in relation to risks of contracting the coronavirus working in person with residents, and of experiencing physical and psychological distress in relation to challenging interactions with staff, residents and their superiors. Situational vulnerability was experienced in relation to demanding workloads, which were intensified in the context of the pandemic. Participants expressed feeling undervalued, unappreciated, and disrespected, reflecting experiences of pathogenic vulnerability. The narratives shared by PSWs highlighted how the COVID-19 pandemic added new, and magnified pre-existing, challenges and vulnerability, affecting their health and well-being.

CONCLUSIONS

Understanding risks faced by PSWs in LTC settings is crucial for developing targeted interventions and policies to support PSWs' health and well-being, mitigate factors that contribute to their vulnerability and promote the long-term sustainability of this caregiving workforce, ultimately enhancing the quality of care provided to residents in LTC facilities.

Prior infections and effectiveness of SARS-CoV-2 vaccine in test-negative studies: a systematic review and meta-analysis

Prior infection with SARS-CoV-2 can provide protection against infection and severe COVID-19. We aimed to determine the impact of preexisting immunity on vaccine effectiveness (VE) estimates. We systematically reviewed and meta-analyzed 66 test-negative design studies that examined VE against infection or severe disease (hospitalization, intensive care unit admission, or death) for primary vaccination series. Pooled VE among studies that included people with prior COVID-19 infection was lower against infection (77%; 95% CI, 72-81) and severe disease (86%; 95% CI, 83-89) compared with studies that excluded people with prior COVID-19 infection (pooled VE against infection: 87% [95% CI, 85-89]; pooled VE against severe disease: 93% [95% CI, 91-95]). There was a negative correlation between VE estimates against infection and severe disease, and the cumulative incidence of cases before the start of the study or incidence rates during the study period. We found clear empirical evidence that higher levels of preexisting immunity were associated with lower VE estimates. Prior infections should be treated as both a confounder and effect modificatory when the policies target the whole population or are stratified by infection history, respectively.

Clinical outcomes of Omicron infection and vaccine acceptance among pediatric liver transplant recipients: insights from a cross-sectional survey

OBJECTIVES

Our study aims to explore the clinical characteristics of Omicron infection in pediatric liver transplant recipients (PLTRs), after the national COVID-19 outbreak. Additionally, we will investigate changes in vaccine coverage and parental attitudes towards vaccinating their children after this current outbreak.

METHODS

We conducted a web-based questionnaire survey to gather information on Omicron infection, vaccination status, and guardian attitude among PLTRs. Besides, utilized valid questionnaire and long-term follow-up information processing techniques, and performed statistical analysis of relevant parameters.

RESULTS

528 valid questionnaires were collected, among which, 251 responses replied Omicron infection status. The Omicron infection rate in Chinese PLTRs was 56.2% (141/251), similar to the report in the normal population (around 60%). 99.3% of infected PLTRs presented mild symptoms, mostly with fever (78.0%), followed by Cough (76.6%), with a mean RTPCR conversion time of 7 days; the overall PLTRs' vaccination rate in this study was 13.3%, similar to that of our previous study (9.4%). Besides, we found no significant differences of either infection rate or clinical symptoms between the vaccinated and unvaccinated groups. Moreover, the study showed 61.6% of guardians supported COVID-19 inoculation despite the outbreak of Omicron status.

CONCLUSIONS

The symptoms of Omicron infection in Chinese PLTRs were relatively mild, vaccine immunization had a limited effect on PLTRs' defense against Omicron infection, besides, their guardians supported the inoculation policy with a caution.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn , identifier ChiCTR2200055968.

Tracheal computed tomography radiomics model for prediction of the Omicron variant of severe acute respiratory syndrome coronavirus 2

OBJECTIVES

The Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is highly contagious, fast-spreading, and insidious. Most patients present with normal findings on lung computed tomography (CT). The current study aimed to develop and validate a tracheal CT radiomics model to predict Omicron variant infection.

MATERIALS AND METHODS

In this retrospective study, a radiomics model was developed based on a training set consisting of 157 patients with an Omicron variant infection and 239 healthy controls between 1 January and 30 April 2022. A set of morphological expansions, with dilations of 1, 3, 5, 7, and 9 voxels, was applied to the trachea, and radiomic features were extracted from different dilation voxels of the trachea. Logistic regression (LR), support vector machines (SVM), and random forests (RF) were developed and evaluated; the models were validated on 67 patients with the Omicron variant and on 103 healthy controls between 1 May and 30 July 2022.

RESULTS

Logistic regression with 12 radiomic features extracted from the tracheal wall with dilation of 5 voxels achieved the highest classification performance compared with the other models. The LR model achieved an area under the curve of 0.993 (95% confidence interval [CI]: 0.987-0.998) in the training set and 0.989 (95% CI: 0.979-0.999) in the validation set. Sensitivity, specificity, and accuracy of the model for the training set were 0.994, 0.946, and 0.965, respectively, whereas those for the validation set were 0.970, 0.952, and 0.959, respectively.

CONCLUSION

The tracheal CT radiomics model reliably identified the Omicron variant of SARS-CoV‑2, and may help in clinical decision-making in future, especially in cases of normal lung CT findings.

Patient-Reported Adverse Events Among Elderly Patients Receiving Novel Oral COVID-19 Antivirals: A Nationwide Sampled Survey in Korea

BACKGROUND

There is a dearth of research on the factors linked with adverse events (AEs) associated with nirmatrelvir/ritonavir (NMVr) and molnupiravir (MOL), particularly in the elderly. Therefore, this study aimed to investigate self-reported AEs and identify factors associated with the occurrence of AEs following NMVr or MOL treatment among survey participants aged 60 years or older in South Korea.

METHODS

This nationwide survey was conducted through in-person interviews using structured questionnaires, from July 24 to August 31, 2023. Eligible participants included individuals aged 60 years or older who had been diagnosed with coronavirus disease 2019 (COVID-19) and received NMVr or MOL. The study outcomes included self-reported demographic, lifestyle, and health characteristics associated with the occurrence of AEs. Multivariate logistic regression analysis was used to estimate the adjusted odds ratio (aOR) and 95% confidence interval (CI) of each characteristic in participants with and without AEs.

RESULTS

Of the 520 participants, 123 (23.7%) experienced at least one AE with oral COVID-19 treatment: 21.0% (96/458) for NMVr and 43.5% (27/62) for MOL. None of the participants reported any serious AEs. Increased odds of AE occurrence were observed in participants treated with MOL compared to those treated with NMVr (aOR, 3.05; 95% CI, 1.67-5.57), a history of two or more compared to one COVID-19 diagnosis (1.93; 1.03-3.62), and self-reported health status as "Unhealthy" compared to "Healthy" (2.65; 1.31-5.36).

CONCLUSION

No AEs required further evaluation to change treatment strategies in elderly patients on NMVr or MOL. Several factors, including the use of MOL, history of COVID-19, and reported health status, were associated with an increased incidence of AEs. Both treatments may still be useful choices for patients with non-severe COVID-19 aged 60 years or older. However, close monitoring of unidentified potential harm and further investigation of the factors associated with the occurrence of AEs are needed.

Association between sore throat and early immune responses against COVID-19 before and after the emergence of the Omicron variant

Background

Sore throat is a prevalent symptom of coronavirus disease 2019 (COVID-19), particularly when caused by the Omicron variants. However, the association between sore throat and immune responses to different severe acute respiratory syndrome coronavirus 2 variants remains unclear. This study aimed to elucidate the characteristics of immune responses associated with sore throat in patients with COVID-19 before and after the emergence of Omicron.

Methods

In this prospective observational study, we enrolled patients with COVID-19 hospitalized between December 2020 and April 2022, which covered the pre-Omicron and Omicron (BA.1 variant) endemic periods. Sore throat was assessed using a daily questionnaire, including an analog scale for sore throat grade (0 to 3) from admission until discharge. Serum levels of immune indicators were assessed using enzyme-linked immunosorbent assay.

Results

A total of 47 patients infected with Omicron and 136 patients infected with preceding variants were included in the analyses. The frequency of sore throat was significantly higher in participants infected with Omicron than that in those infected with preceding variants (66% vs. 42%, P<0.005). Sore throat was associated with nasopharyngeal viral load, interleukin-6 (IL-6)/interferon-α (IFN-α) levels in participants infected with preceding variants, whereas, it was associated with age, the body mass index, and interferon-λ1 (IFN-λ1) in participants infected with Omicron.

Conclusions

Infection with the Omicron variant is characterized by increased sore throat frequency and altered associations between sore throat and several immune indicators, including IFN-α, IL-6, and IFN-λ1.

Assessing Excess Mortality of Baby Boomers from the COVID-19 Pandemic: Taiwan Omicron-naïve Cohort

BACKGROUND

Asia's elderly Baby Boomer demographic (born between 1946 and 1964) faced a huge problem during the COVID-19 pandemic due to increased all-cause mortality. We aimed to provide a unique Taiwan situation regarding the impact of Baby Boomers on excess mortalities from all causes relative to non-Baby Boomers throughout distinct times of SARS-CoV-2 mutations during the COVID-19 pandemic.

METHODS

We used the Poisson time series design with a Bayesian directed acyclic graphic approach to build the background mortality prior to the COVID-19 pandemic between 2015 and 2019. It was then used for predicting the expected all-cause deaths compared to the reported figures during the COVID-19 pandemic period based on Taiwan residents, an Omicron-naïve cohort.

RESULTS

Baby Boomers experienced a 2% negative excess mortality in 2020 (Wuhan/D614G) and a 4% excess mortality in 2021 (Alpha/Delta) with a rising background mortality trend whereas non-Baby Boomers showed the corresponding figures of 4% negative excess and 1% excess with a stable trend. Baby Boomer and non-Baby Boomer excess mortality soared to 9% (95% CI: 7-10%) and 10% (95% CI: 9-11%), respectively, during the epidemic Omicron period from January to June 2022. Surprisingly, Baby Boomers aged 58-76 experienced the same 9% excess mortality as non-Baby Boomers aged 77 and beyond. Non-COVID-19 deaths were more prevalent among Baby Boomers than non-Baby Boomers (33% vs. 29%).

CONCLUSION

Baby Boomers were more likely to die from COVID-19 in early pandemic and had more non-COVID-19 deaths in late pandemic than older non-Baby Boomers demonstrated in Taiwan Omicron-naïve cohort. For this vulnerable population, adequate access to medical care and medical capacity require more consideration.

Impact of vaccination on SARS-CoV-2 evolution and immune escape variants

Vaccines and host genetic factors can influence the SARS-CoV-2 evolution and emergence of new variants. Even vaccinated cases get affected as virus continues to evolve, raising concerns about vaccine efficacy and the emergence of immune escape variants. Here, we have analyzed 2295 whole-genome sequences of SARS-CoV-2 collected from vaccinated and unvaccinated cases to evaluate the impact of vaccines on virus diversity within hosts. Our comparative analysis revealed a significant higher incidence of intra-host single nucleotides variants (iSNVs) in vaccinated cases compared to unvaccinated ones (p value<0.0001). Furthermore, we have found that specific mutational processes, including APOBEC (C > T) mediated and ADAR1 (A > G) mediated mutations, were found more prevalent in vaccinated cases. Vaccinated cases exhibited higher accumulation of nonsynonymous mutation than unvaccinated cases. Fixed iSNVs were predominantly located in the ORF1ab and spike genes, several key omicron defining immune escape variants S477N, Q493R, Q498R, Y505H, L452R, and N501Y were identified in the RBD domain of spike gene in vaccinated cases. Our findings suggest that vaccine plays an important role in the evolution of the virus genome. The virus genome acquires random mutations due to error-prone replication of the virus, host modification through APOBEC and ADAR1 mediated editing mechanism, and oxidative stress. These mutations become fixed in the viral population due to the selective pressure imposed by vaccination.

Development and characterization of monoclonal antibodies recognizing nucleocapsid protein of multiple SARS-CoV-2 variants

Rapid antigen test (RAT) is widely used for SARS-CoV-2 infection diagnostics. However, test sensitivity has decreased recently due to the emergence of the Omicron variant and its sublineages. Here we developed a panel of SARS-CoV-2 nucleocapsid protein (NP) specific mouse monoclonal antibodies (mAbs) and assessed their sensitivity and specificity to important SARS-CoV-2 variants. We identified seven mAbs that exhibited strong reactivity to SARS-CoV-2 variants and recombinant NP (rNP) by Western immunoblot or ELISA. Their specificity to SARS-CoV-2 was confirmed by negative or low reactivity to rNPs from SARS-CoV-1, MERS, and common human coronaviruses (HCoV-HKU1, HCoV-CO43, HCoV-NL63, and HCoV-229E). These seven mAbs were further tested by immunoplaque assay against selected variants of concern (VOCs), including two Omicron sublineages, and five mAbs (F461G13, F461G7, F459G7, F457G3, and F461G6), showed strong reactions, warranting further suitability testing for the development of diagnostic assay.

Detection of SARS-CoV-2 Variants Imported Through Land Borders at the Height of the COVID-19 Pandemic in Ghana, 2022

Background The World Health Organization recommends surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at points of entry to systematically collect and analyze data to inform decisions about the effective and appropriate use of resources needed for interventions. This study sought to determine the prevalence of SARS-CoV-2 and its variants imported into Ghana by travelers entering the country via land borders from February to July 2022. Methods A cross-sectional approach was employed, where recruited participants consented to the collection of oropharyngeal and nasopharyngeal samples. Specimens were analyzed for the presence of SARS-CoV-2 ribonucleic acid (RNA) using a commercially available VeriQ nCoV-OM COVID-19 Multiplex Detection kit. Amplicon sequencing protocols (ARTIC network, Oxford Nanopore Technologies (ONT), New England Biolabs, British Columbia Centre for Disease Control (BCCDC), COVID-19 Genomics UK (COG-UK), Canadian COVID-19 Genomics Network (CanCOGen), and ONT MinION) were used for SARS-CoV-2 sequencing. Logistic regression and phylogenetic analyses were conducted on the generated data. Results We detected a SARS-CoV-2 prevalence of 3.6% (170/4,621) among a total of 4,621 travelers screened. The average age of travelers was 32.11 ± 11.77, with the majority being male (68%, 3,132/4,621). After adjusting for educational status, household size, vaccination status, and study site, those with primary and tertiary education levels had 1.74 (95% CI: 1.16-2.62, P = 0.007) and 2.27 (95% CI: 1.27-4.05, P = 0.006) higher odds of testing positive for SARS-CoV-2 compared to those with no education. Vaccinated travelers had 0.65 odds (95% CI: 0.48-0.89, P = 0.007) of testing positive for SARS-CoV-2. The Omicron variant (B.1.1.529) emerged as the predominant lineage, constituting 77% (27/35) of isolates, compared to Alpha, Delta, and Recombinant variants. Phylogenetic analysis corroborated this finding, highlighting Delta and Omicron as the dominant circulating SARS-CoV-2 variants. Notably, Ghanaian strains from this study clustered with global variants, suggesting multiple introductions, likely through land borders. Conclusion A low prevalence of SARS-CoV-2 was recorded in this study, prompting the decision to reopen land borders and ease pandemic-related travel restrictions. Omicron was identified as the dominant variant. These findings emphasize the crucial role of routine surveillance at port health and advocate for a collaborative approach to addressing public health crises, preventing unnecessary travel and trade restrictions through data-based decision-making.

Impact of non-emergency surgical timing on postoperative recovery quality in mild or asymptomatic SARS-CoV-2 infected patients: a grouped cohort study

OBJECTIVE

To explore the relationship between the timing of non-emergency surgery in mild or asymptomatic SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infected individuals and the quality of postoperative recovery from the time of confirmed infection to the day of surgery.

METHODS

We retrospectively reviewed the medical records of 300 cases of mild or asymptomatic SARS-CoV-2 infected patients undergoing elective general anaesthesia surgery at Yijishan Hospital between January 9, 2023, and February 17, 2023. Based on the time from confirmed SARS-CoV-2 infection to the day of surgery, patients were divided into four groups: ≤2 weeks (Group A), 2-4 weeks (Group B), 4-6 weeks (Group C), and 6-8 weeks (Group D). The primary outcome measures included the Quality of Recovery-15 (QoR-15) scale scores at 3 days, 3 months, and 6 months postoperatively. Secondary outcome measures included postoperative mortality, ICU admission, pulmonary complications, postoperative length of hospital stay, extubation time, and time to leave the PACU.

RESULTS

Concerning the primary outcome measures, the QoR-15 scores at 3 days postoperatively in Group A were significantly lower compared to the other three groups (P < 0.05), while there were no statistically significant differences among the other three groups (P > 0.05). The QoR-15 scores at 3 and 6 months postoperatively showed no statistically significant differences among the four groups (P > 0.05). In terms of secondary outcome measures, Group A had a significantly prolonged hospital stay compared to the other three groups (P < 0.05), while other outcome measures showed no statistically significant differences (P > 0.05).

CONCLUSION

The timing of surgery in mild or asymptomatic SARS-CoV-2 infected patients does not affect long-term recovery quality but does impact short-term recovery quality, especially for elective general anaesthesia surgeries within 2 weeks of confirmed infection. Therefore, it is recommended to wait for a surgical timing of at least greater than 2 weeks to improve short-term recovery quality and enhance patient prognosis.

Omicron variant and pulmonary involvements: a chest imaging analysis in asymptomatic and mild COVID-19

Objectives

To identify clinical characteristics and risk factors for pulmonary involvements in asymptomatic and mildly symptomatic patients infected with SARS-CoV-2 Omicron variant by chest imaging analysis.

Methods

Detailed data and chest computed tomography (CT) imaging features were retrospectively analyzed from asymptomatic and mildly symptomatic patients infected with Omicron between 24 April and 10 May 2022. We scored chest CT imaging features and categorized the patients into obvious pulmonary involvements (OPI) (score > 2) and not obvious pulmonary involvements (NOPI) (score ≤ 2) groups based on the median score. The risk factors for OPI were identified with analysis results visualized by nomogram.

Results

In total, 339 patients were included (145 were male and 194 were female), and the most frequent clinical symptoms were cough (75.5%); chest CT imaging features were mostly linear opacities (42.8%). Pulmonary involvements were more likely to be found in the left lower lung lobe, with a significant difference in the lung total severity score of the individual lung lobes (p < 0.001). Logistic regression analysis revealed age stratification [odds ratio (OR) = 1.92, 95% confidence interval (CI) (1.548-2.383); p < 0.001], prolonged nucleic acid negative conversion time (NCT) (NCT > 8d) [OR = 1.842, 95% CI (1.104-3.073); p = 0.019], and pulmonary diseases [OR = 4.698, 95% CI (1.159-19.048); p = 0.03] as independent OPI risk factors.

Conclusion

Asymptomatic and mildly symptomatic patients infected with Omicron had pulmonary involvements which were not uncommon. Potential risk factors for age stratification, prolonged NCT, and pulmonary diseases can help clinicians to identify OPI in asymptomatic and mildly symptomatic patients infected with Omicron.

Clinical characterisation, treatment outcomes, and case fatality risk of patients with different SARS-CoV-2 variants in Bangladesh

Background

Bangladesh underwent four waves of the coronavirus disease 2019 (COVID-19) pandemic. Analysing them is essential for understanding changes in viral behaviour, disease patterns, severity, and response to treatment. Nevertheless, data are scarce in low- and middle-income countries. Therefore, we aimed to compare clinical manifestations; outcomes for therapy with oxygen, dexamethasone, and remdesivir; as well as the case fatality during the ancestral, alpha/beta, delta, and omicron-driven waves.

Methods

We conducted an observational study at five hospitals in Dhaka, Bangladesh, with at least one dedicated COVID-19 unit for treating patients that followed national guidelines between November 2020 and February 2022. We collected data prospectively between 1 July 2021 and 30 September 2021 (delta) and retrospectively from 1 November 2020 to 4 March 2021 (ancestral), 5 March 2021 to 30 May 2021 (alpha/beta), and 1 January 2022 to 28 February 2022 (omicron), with the periods representing distinct waves of COVID-19. The primary outcome was 30-day case fatality across the waves. We used multivariable robust Poisson regression models with robust variance to estimate the 30-day case fatality risk ratio during various waves.

Results

Among 966 participants, the rate of 30-day case fatality was comparable across different variants. However, the proportions of patients with fever (P < 0.001), cough (P < 0.001), breathing difficulty (P < 0.001), nausea (P < 0.001), fatigue (P < 0.001), headache (P < 0.001), diarrhoea (P < 0.001), loss of smell (P < 0.001), runny nose (P < 0.001), and chest pain (P = 0.001) were smaller during the omicron wave than the other three waves. After adjusting for potential confounders, the multivariable model showed that the likelihood of case fatality was significantly associated with age (adjusted risk ratio (aRR) = 1.05; 95% confidence interval (CI) = 1.04-1.07); hypoxaemia (aRR = 5.29; 95% CI = 1.58-17.7); critical disease (aRR = 6.45; 95% CI = 1.89-21.99), and modified early warning score ≥4 (aRR = 2.58; 95% CI = 1.71-3.88). We observed an 85% (aRR = 0.15; 95% CI = 0.03-0.72) reduction in case fatality among patients with any oxygen (L/min) compared to those without oxygen. However, individuals requiring ≥15 L/min of oxygen showed a significantly higher case fatality compared to those needing <15 L/min oxygen (aRR = 5.63; 95% CI = 2.68-11.81 for ancestral variant, aRR = 2.83; 95% CI = 1.25-6.41 for alpha/beta variant, aRR = 2.73; 95% CI = 1.56-4.77 for delta variant, aRR = 2.84; 95% CI = 1.56-5.16 for omicron variant). Remdesivir was associated with an increased case fatality during alpha/beta (aRR = 6.96; 95% CI = 1.54-31.43), delta (aRR = 4.13; 95% CI = 1.17-14.58), and omicron waves (aRR = 8.89; 95% CI = 2.46-32.13) compared to the ancestral wave. Dexamethasone administered during admission did not have any significant association with death (P = 0.239) in the entire cohort. However, dexamethasone reduced case fatality by 78% among the moderate to severe COVID-19 subgroup. We observed a 37% reduction in case fatality among vaccinated participants compared to those without vaccination (aRR = 0.63; 95% CI = 0.40-0.99).

Conclusions

Our study provides insights into the clinical patterns, treatment impact, and case fatality across various SARS-CoV-2 variants in resource-limited settings. The findings underscored the crucial role of oxygen therapy and vaccination in reducing COVID-19 case fatality. They also emphasise the necessity for continuous disease surveillance and highlight the importance of close monitoring of patients with higher oxygen requirements (≥15 L/min) due to their association with fatal outcomes, as well as the significance of sustaining vaccination efforts and the need for clinical trials of newer antivirals in the ongoing battle against COVID-19.

Complexity and Diversity of the Neurological Spectrum of SARS-CoV-2 over Three Waves of COVID-19

Background/Objectives: SARS-CoV-2 continually mutates, with five identified variants. Many neurological manifestations were observed during the COVID-19 pandemic, with differences between virus variants. The aim of this study is to assess the frequency and characteristics of neurological manifestations during COVID-19 in hospitalized patients over three waves in Poland with comparison and analysis correlation with the course of infection. Methods: This retrospective single-center study included 600 consecutive adults with confirmed COVID-19, hospitalized during 3 waves (pre-Delta, Delta and Omicron) in Poland. Demographic and clinical information and neurological manifestations were collected and compared across three periods. Results: The median age of the study group was 68, lower during the Delta wave. In the Omicron period, the disease severity at admission and inflammatory markers concentration were the lowest. Neurological manifestations were observed in 49%. The most common were altered mentation, headache, myalgia, mood disorder, ischemic stroke and encephalopathy. Smell and taste disturbances (STDs) were less frequent in the Omicron period. Neurological complications were predominant in the pre-Delta and Omicron periods. Ischemic stroke was observed more often in pre-Delta period. Altered mentation was related to higher severity at admission, worse lab test results, higher admission to ICU and mortality, while headache reduced mortality. Pre-existing dementia was related to higher mortality. Conclusions: Neurological manifestations of COVID-19 are frequent, with a lower rate of STDs in the Omicron period and more often cerebrovascular diseases in the pre-Delta period. Headache improves the course of COVID-19, while altered mentation, stroke and neurological comorbidities increase severity and mortality.

SARS-CoV-2: pathogenesis, therapeutics, variants, and vaccines

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in December 2019 with staggering economic fallout and human suffering. The unique structure of SARS-CoV-2 and its underlying pathogenic mechanism were responsible for the global pandemic. In addition to the direct damage caused by the virus, SARS-CoV-2 triggers an abnormal immune response leading to a cytokine storm, culminating in acute respiratory distress syndrome and other fatal diseases that pose a significant challenge to clinicians. Therefore, potential treatments should focus not only on eliminating the virus but also on alleviating or controlling acute immune/inflammatory responses. Current management strategies for COVID-19 include preventative measures and supportive care, while the role of the host immune/inflammatory response in disease progression has largely been overlooked. Understanding the interaction between SARS-CoV-2 and its receptors, as well as the underlying pathogenesis, has proven to be helpful for disease prevention, early recognition of disease progression, vaccine development, and interventions aimed at reducing immunopathology have been shown to reduce adverse clinical outcomes and improve prognosis. Moreover, several key mutations in the SARS-CoV-2 genome sequence result in an enhanced binding affinity to the host cell receptor, or produce immune escape, leading to either increased virus transmissibility or virulence of variants that carry these mutations. This review characterizes the structural features of SARS-CoV-2, its variants, and their interaction with the immune system, emphasizing the role of dysfunctional immune responses and cytokine storm in disease progression. Additionally, potential therapeutic options are reviewed, providing critical insights into disease management, exploring effective approaches to deal with the public health crises caused by SARS-CoV-2.

SARS-CoV-2 Disease Severity and Cycle Threshold Values in Children Infected during Pre-Delta, Delta, and Omicron Periods, Colorado, USA, 2021-2022

In adults, viral load and disease severity can differ by SARS-CoV-2 variant, patterns less understood in children. We evaluated symptomatology, cycle threshold (Ct) values, and SARS-CoV-2 variants among 2,299 pediatric SARS-CoV-2 patients (0-21 years of age) in Colorado, USA, to determine whether children infected with Delta or Omicron had different symptom severity or Ct values than during earlier variants. Children infected during the Delta and Omicron periods had lower Ct values than those infected during pre-Delta, and children <1 year of age had lower Ct values than older children. Hospitalized symptomatic children had lower Ct values than asymptomatic patients. Compared with pre-Delta, more children infected during Delta and Omicron were symptomatic (75.4% pre-Delta, 95.3% Delta, 99.5% Omicron), admitted to intensive care (18.8% pre-Delta, 39.5% Delta, 22.9% Omicron), or received oxygen support (42.0% pre-Delta, 66.3% Delta, 62.3% Omicron). Our data reinforce the need to include children, especially younger children, in pathogen surveillance efforts.

The effectiveness of booster vaccination of inactivated COVID-19 vaccines against susceptibility, infectiousness, and transmission of omicron BA.2 variant: a retrospective cohort study in Shenzhen, China

Little studies evaluated the effectiveness of booster vaccination of inactivated COVID-19 vaccines against being infected (susceptibility), infecting others (infectiousness), and spreading the disease from one to another (transmission). Therefore, we conducted a retrospective cohort study to evaluate the effectiveness of booster vaccination of inactivated COVID-19 vaccines against susceptibility, infectiousness, and transmission in Shenzhen during an Omicron BA.2 outbreak period from 1 February to 21 April 2022. The eligible individuals were classified as four sub-cohorts according to the inactivated COVID-19 vaccination status of both the close contacts and their index cases: group 2-2, fully vaccinated close contacts seeded by fully vaccinated index cases (reference group); group 2-3, booster-vaccinated close contacts seeded by fully vaccinated index cases; group 3-2, fully vaccinated close contacts seeded by booster-vaccinated index cases; and group 3-3, booster-vaccinated close contacts seeded by booster-vaccinated index cases. Univariate and multivariate logistic regression analyses were applied to estimate the effectiveness of booster vaccination. The sample sizes of groups 2-2, 2-3, 3-2, and 3-3 were 846, 1,115, 1,210, and 2,417, respectively. We found that booster vaccination had an effectiveness against infectiousness of 44.9% (95% CI: 19.7%, 62.2%) for the adults ≥ 18 years, 62.2% (95% CI: 32.0%, 78.9%) for the female close contacts, and 60.8% (95% CI: 38.5%, 75.1%) for the non-household close contacts. Moreover, booster vaccination had an effectiveness against transmission of 29.0% (95% CI: 3.2%, 47.9%) for the adults ≥ 18 years, 38.9% (95% CI: 3.3%, 61.3%) for the female close contacts, and 45.8% (95% CI: 22.1%, 62.3%) for the non-household close contacts. However, booster vaccination against susceptibility did not provide any protective effect. In summary, this study confirm that booster vaccination of the inactivated COVID-19 vaccines provides low level of protection and moderate level of protection against Omicron BA.2 transmission and infectiousness, respectively. However, booster vaccination does not provide any protection against Omicron BA.2 susceptibility.

Factors Associated with Mortality Among Severe Omicron Patients for COVID-19

Purpose

The purpose of the study was to explore the potential risk factors of mortality in patients with severe pneumonia during the omicron pandemic in South China in 2022.

Methods

Clinical data was collected from patients hospitalized with omicron COVID-19. Then, patients were categorized into the non-survival and survival groups. A comprehensive analysis was conducted to analyze the factors associated with negative outcome in individuals suffering from severe omicron COVID-19.

Results

In this study, 155 severe COVID-19 patients were included, comprising 55 non-survivors and 100 survivors. Non-survivors, in comparison to survivors, exhibited elevated levels of various biomarkers including neutrophil count, hypersensitive troponin T, urea, creatinine, C-reactive protein, procalcitonin, interleukin-6, plasma D-dimer, and derived neutrophil-to-lymphocyte ratio (dNLR) (P < 0.05). They also displayed reduced lymphocyte count, platelet count, and albumin levels (P < 0.05) and were more prone to developing comorbidities, including shock, acute cardiac and renal injury, acute respiratory distress syndrome, coagulation disorders, and secondary infections. Platelet count (PLT) <100 × 10^/L, interleukin-6 (IL-6) >100 pg/mL, and dNLR >5.0 independently contributed to the risk of death in patients suffering from severe COVID-19.

Conclusion

PLT, IL-6, and dNRL independently contributed to the risk of mortality in patients with severe pneumonia during the 2022 omicron pandemic in South China.

Artificial Neural Network Prediction of COVID-19 Daily Infection Count

This study addresses COVID-19 testing as a nonlinear sampling problem, aiming to uncover the dependence of the true infection count in the population on COVID-19 testing metrics such as testing volume and positivity rates. Employing an artificial neural network, we explore the relationship among daily confirmed case counts, testing data, population statistics, and the actual daily case count. The trained artificial neural network undergoes testing in in-sample, out-of-sample, and several hypothetical scenarios. A substantial focus of this paper lies in the estimation of the daily true case count, which serves as the output set of our training process. To achieve this, we implement a regularized backcasting technique that utilize death counts and the infection fatality ratio (IFR), as the death statistics and serological surveys (providing the IFR) as more reliable COVID-19 data sources. Addressing the impact of factors such as age distribution, vaccination, and emerging variants on the IFR time series is a pivotal aspect of our analysis. We expect our study to enhance our understanding of the genuine implications of the COVID-19 pandemic, subsequently benefiting mitigation strategies.

Dynamic changes of Bacterial Microbiomes in Oropharynx during Infection and Recovery of COVID-19 Omicron Variant

Oropharyngeal microbiomes play a significant role in the susceptibility and severity of COVID-19, yet the role of these microbiomes play for the development of COVID-19 Omicron variant have not been reported. A total of 791 pharyngeal swab samples were prospectively included in this study, including 297 confirmed cases of Omicron variant (CCO), 222 confirmed case of Omicron who recovered (CCOR), 73 confirmed cases of original strain (CCOS) and 199 healthy controls (HC). All samples completed MiSeq sequencing. The results showed that compared with HC, conditional pathogens increased in CCO, while acid-producing bacteria decreased. Based on six optimal oropharyngeal operational taxonomy units (OTUs), we constructed a marker microbial classifier to distinguish between patients with Omicron variant and healthy people, and achieved high diagnostic efficiency in both the discovery queue and the verification queue. At same time, we introduced a group of cross-age infection verification cohort and Omicron variant subtype XBB.1.5 branch, which can be accurately distinguished by this diagnostic model. We also analyzed the characteristics of oropharyngeal microbiomes in two subgroups of Omicron disease group-severity of infection and vaccination times, and found that the change of oropharyngeal microbiomes may affect the severity of the disease and the efficacy of the vaccine. In addition, we found that some genera with significant differences gradually increased or decreased with the recovery of Omicron variant infection. The results of Spearman analysis showed that 27 oropharyngeal OTUs were closely related to 6 clinical indexes in CCO and HC. Finally, we found that the Omicron variant had different characterization of oropharyngeal microbiomes from the original strain. Our research characterizes oropharyngeal microbiomes of Omicron variant cases and rehabilitation cases, successfully constructed and verified the non-invasive diagnostic model of Omicron variant, described the correlation between microbial OTUs and clinical indexes. It was found that the infection of Omicron variant and the infection of original strain have different characteristics of oropharyngeal microbiomes.

Factors associated with the worsening of COVID-19 symptoms among cohorts in community- or home-isolation care in southern Thailand

Introduction

This study aimed to investigate factors associated with time-to-referral due to worsening symptoms in patients with laboratory-confirmed COVID-19 in southern Thailand. While underlying diseases have been evaluated to assess COVID-19 severity, the influence of vaccinations and treatments is also crucial.

Methods

A cohort of 8,638 patients quarantined in home or community isolation with laboratory-confirmed COVID-19 was analyzed. Survival analysis and the Cox proportional hazard ratio were employed to assess factors influencing time-toreferral.

Results

Age ≥ 60 years, neurologic disorders, cardiovascular disease, and human immunodeficiency virus infection were identified as significant risk factors for severe COVID-19 referral. Patients who received full- or booster-dose vaccinations had a lower risk of experiencing severe symptoms compared to unvaccinated patients. Notably, individuals vaccinated during the Omicron-dominant period had a substantially lower time-to-referral than those unvaccinated during the Delta-dominant period. Moreover, patients vaccinated between 1 and 6 months prior to infection had a significantly lower risk of time-to-referral than the reference group.

Discussion

These findings demonstrate early intervention in high-risk COVID-19 patients and the importance of vaccination efficacy to reduce symptom severity. The study provides valuable insights for guiding future epidemic management strategies and optimising patient care during infectious disease outbreaks.

The Course of COVID-19 and Long COVID: Identifying Risk Factors among Patients Suffering from the Disease before and during the Omicron-Dominant Period

SARS-CoV-2 has acquired many mutations that influence the severity of COVID-19's course or the risk of developing long COVID. In 2022, the dominant SARS-CoV-2 variant was Omicron. This study aimed to compare the course of COVID-19 in the periods before and during the dominance of the Omicron variant. Risk factors for developing long COVID were also assessed. This study was based on stationary visits of patients after COVID-19 and follow-up assessments after 3 months. Clinical symptoms, comorbidities, and vaccination status were evaluated in 1967 patients. Of the analyzed group, 1308 patients (66.5%) were affected by COVID-19 in the period before the Omicron dominance. The prevalence of long COVID was significantly lower among patients of the Omicron group (47.7% vs. 66.9%, p < 0.001). The risk of long COVID was higher for women (OR: 1.61; 95% CI: 1.31, 1.99]) and asthmatics (OR: 1.46; 95% CI: 1.03, 2.07]). Conclusively, infection during the Omicron-dominant period was linked to a lower risk of developing long COVID. Females are at higher risk of developing long COVID independent of the pandemic period. Individuals affected by COVID-19 in the Omicron-dominant period experience a shorter duration of symptoms and reduced frequency of symptoms, except for coughing, which occurs more often.

A cohort study of patients hospitalised with SARS-CoV-2 infection in Ontario: patient characteristics and outcomes by wave

INTRODUCTION

Each wave of the COVID-19 pandemic exhibited a unique combination of epidemiological, social and structural characteristics. We explore similarities and differences in wave-over-wave characteristics of patients hospitalised with COVID-19.

METHODS

This was a population-based study in Ontario province, Canada. Patients hospitalised with SARS-CoV-2 between 26 February 2020 and 31 March 2022 were included. An admission was considered related to SARS-CoV-2 infection if the provincial inpatient or outpatient hospital databases contained the ICD-10 diagnostic codes U071/U072 or the Ontario Laboratories Information System indicated a positive SARS-CoV-2 test result (PCR or rapid antigen testing) during the admission or up to two weeks prior. The primary outcome was 90-day mortality (modified Poisson regression). Secondary outcomes were use of critical care during the admission (logistic regression) and total length-of-stay (linear regression with heteroskedastic-consistent standard-error estimators). All models were adjusted for demographic characteristics, neighbourhood socioeconomic factors and indicators of illness severity.

RESULTS

There were 73,201 SARS-CoV-2-related admissions: 6127 (8%) during wave 1 (wild-type), 14,371 (20%) during wave 2 (wild-type), 16,653 (23%) during wave 3 (Alpha), 5678 (8%) during wave 4 (Delta) and 30,372 (42%) during wave 5 (Omicron). SARS-CoV-2 was the most responsible diagnosis for 70% of admissions during waves 1-2 and 42% in wave 5. The proportion of admitted patients who were long-term care residents was 18% (n = 1111) during wave 1, decreasing to 10% (n = 1468) in wave 2 and <5% in subsequent waves. During waves 1-3, 46% of all admitted patients resided in a neighbourhood assigned to the highest ethnic diversity quintile, which declined to 27% during waves 4-5. Compared to wave 1, 90-day mortality was similar during wave 2 (adjusted risk ratio [aRR]: 1.00 [95% CI: 0.95-1.04]), but lower during wave 3 (aRR: 0.89 [0.85-0.94]), wave 4 (aRR: 0.85 [0.79-0.91]) and wave 5 (aRR: 0.83 [0.80-0.88]). Improvements in survival over waves were observed among elderly patients (p-interaction <0.0001). Critical care admission was significantly less likely during wave 5 than previous waves (adjusted odds ratio: 0.50 [0.47-0.54]). The length of stay was a median of 8.5 (3.6-23.8) days during wave 1 and 5.3 (2.2-12.6) during wave 5. After adjustment, the mean length of stay was on average -10.4 (-11.1 to -9.8) days, i.e. shorter, in wave 5 vs wave 1.

CONCLUSION

Throughout the pandemic, sociodemographic characteristics of patients hospitalised with SARS-CoV-2 changed over time, particularly in terms of ethnic diversity, but still disproportionately affected patients from more marginalised regions. Improved survival and reduced use of critical care during the Omicron wave are reassuring.

Changing impact of COVID-19 on life expectancy 2019-2023 and its decomposition: Findings from 27 countries

Background

The World Health Organization declared COVID-19 no longer a global health emergency on 5th May 2023; however, the impact of COVID-19 on life expectancy throughout the pandemic period is not clear. This study aimed to quantify and decompose the changes in life expectancy during 2019-2023 and corresponding age and gender disparities in 27 countries.

Methods

Data were sourced from the Human Mortality Database, the World Population Prospects 2022 and the United Kingdom's Office for National Statistics. Life expectancy was estimated using the abridged life table method, while differentials of life expectancies were decomposed using the age-decomposition algorithm.

Results

There was an overall reduction in life expectancy at age 5 among the 27 countries in 2020. Life expectancy rebounded in Western, Northern and Southern Europe in 2021 but further decreased in the United States, Chile and Eastern Europe in the same year. In 2022 and after, lost life expectancy years in the United States, Chile and Eastern Europe were slowly regained; however, as of 7th May 2023, life expectancy in 22 of the 27 countries had not fully recovered to its pre-pandemic level. The reduced life expectancy in 2020 was mainly driven by reduced life expectancy at age 65+, while that in subsequent years was mainly driven by reduced life expectancy at age 45-74. Women experienced a lower reduction in life expectancy at most ages but a greater reduction at age 85+.

Conclusions

The pandemic has caused substantial short-term mortality variations during 2019-2023 in the 27 countries studied. Although most of the 27 countries experienced increased life expectancy after 2022, life expectancy in 22 countries still has not entirely regained its pre-pandemic level by May 2023. Threats of COVID-19 are more prominent for older adults and men, but special attention is needed for women aged 85+ years.

Anti SARS-CoV-2 Monoclonal Antibodies in Pre-Exposure or Post-Exposure in No- or Weak Responder to Vaccine Kidney Transplant Recipients: Is One Strategy Better than Another?

Background: Kidney transplant recipients (KTRs) are likely to develop severe COVID-19 and are less well-protected by vaccines than immunocompetent subjects. Thus, the use of neutralizing anti-SARS-CoV-2 monoclonal antibodies (mAbs) to confer a passive immunity appears attractive in KTRs. Methods: This retrospective monocentric cohort study was conducted between 1 January 2022 and 30 September 2022. All KTRs with a weak antibody response one month after three doses of mRNA vaccine (anti spike IgG < 264 (BAU/mL)) have received tixagevimab-cilgavimab in pre-exposure (group 1), post-exposure (group 2) or no specific treatment (group 3). We compared COVID-19 symptomatic hospitalizations, including intensive care unit hospitalizations, oxygen therapy, and death, between the three groups. Results: A total of 418 KTRs had SARS-CoV-2 infection in 2022. During the study period, we included 112 KTRs in group 1, 40 KTRs in group 2, and 27 KTRs in group 3. The occurrence of intensive care unit hospitalization, oxygen therapy, and COVID-19 death was significantly increased in group 3 compared to group 1 or 2. In group 3, 5 KTRs (18.5%) were admitted to the intensive care unit, 7 KTRs (25.9%) needed oxygen therapy, and 3 KTRs (11.1%) died. Patients who received tixagevimab-cilgavimab pre- or post-exposure had similar outcomes. Conclusions: This retrospective real-life study supports the relative effectiveness of tixagevimab-cilgavimab on COVID-19 infection caused by Omicron, used as a pre- or post-exposure therapy. The continued evolution of Omicron variants has made tixagevimab-cilgavimab ineffective and reinforces the need for new therapeutic monoclonal antibodies for COVID-19 active on new variants.

Impact of Vaccination and Nonpharmaceutical Interventions With Possible COVID-19 Viral Evolutions Using an Agent-Based Simulation

Introduction

The COVID-19 pandemic continues with highly contagious variants and waning immunity. As the virus keeps evolving to be more infectious and immune evasive, some question whether the COVID-19 pandemic can be managed through sustainable public health measures.

Methods

We developed an agent-based simulation to explore the impact of COVID-19 mutations, periodic vaccinations, and nonpharmaceutical interventions on reducing COVID-19 deaths. The model is calibrated to the greater Seattle area by observing local epidemic data. We perform scenario analyses on viral mutations that change infectiousness, disease severity, and immune evasiveness from previous infections and vaccination every 6 months. The simulation is run until the end of year 2023.

Results

Variants with increased infectivity or increased immune evasion dominate previous strains. With enhanced immune protection from a pancoronavirus vaccine, the most optimistic periodic vaccination rate reduces average total deaths by 44.6% compared with the most pessimistic periodic vaccination rate. A strict threshold nonpharmaceutical intervention policy reduces average total deaths by 71.3% compared with an open society, whereas a moderate nonpharmaceutical intervention policy results in a 33.6% reduction.

Conclusions

Our findings highlight the potential benefits of pancoronavirus vaccines that offer enhanced and longer-lasting immunity. We emphasize the crucial role of nonpharmaceutical interventions in reducing COVID-19 deaths regardless of virus mutation scenarios. Owing to highly immune evasive and contagious SARS-CoV-2 variants, most scenarios in this study fail to reduce the mortality of COVID-19 to the level of influenza and pneumonia. However, our findings indicate that periodic vaccinations and a threshold nonpharmaceutical intervention policy may succeed in achieving this goal. This indicates the need for caution and vigilance in managing a continuing COVID-19 epidemic.

Prognostic Factors for Predicting Post-COVID-19 Condition in Patients With COVID-19 in an Outpatient Setting

BACKGROUND

Although data on post-coronavirus disease 2019 (COVID-19) conditions are extensive, the prognostic factors affecting symptom duration in non-hospitalized patients with COVID-19 are currently not well known. We aimed to investigate the various prognostic factors affecting symptom duration among outpatients with COVID-19.

METHODS

Data were analyzed from 257 patients who were diagnosed with mild COVID-19 and visited the 'post-COVID-19 outpatient clinic' between April and December 2022 after a mandatory isolation period. The symptom duration was measured from diagnosis to symptom resolution. Laboratory and pulmonary function test results from their first visit were collected.

RESULTS

The mean age of patients was 55.7 years, and the median symptom duration was 57 days. The development of post-COVID-19 conditions (> 12 weeks) were significantly correlated with not using antiviral drugs, leukocytosis (white blood cell > 10,000/µL), lower 25(OH)D3 levels, forced vital capacity (FVC) < 90% predicted, and presence of dyspnea and anxiety/depression. Additionally, in multivariable Cox regression analysis, not using antiviral drugs, lower 25(OH)D3 levels, and having dyspnea were poor prognostic factors for longer symptom duration. Particularly, vitamin D deficiency (< 20 ng/mL) and not using antivirals during the acute phase were independent poor prognostic factors for both post-COVID-19 condition and longer symptom duration.

CONCLUSION

The non-use of antivirals, lower 25(OH)D3 levels, leukocytosis, FVC < 90% predicted, and the presence of dyspnea and anxiety/depression symptoms could be useful prognostic factors for predicting post-COVID-19 condition in outpatients with COVID-19. We suggest that the use of antiviral agents during the acute phase and vitamin D supplements might help reduce COVID-19 symptom duration.

Association between serum C-reactive protein (CRP) and Omicron variant COVID-19 pneumonia in cancer patients: A multicenter cross-sectional study at the end of 2022 in China

Cancer patients with COVID-19 have a higher infection rate and mortality rate than non-cancer patients. However, there are few studies on the correlation between the serum C-reactive protein (CRP) and cancer patients with COVID-19. This study aims to investigate the association between serum CRP and the incidence of COVID-19 pneumonia in cancer patients at the end of 2022 in China. This cross-sectional study with a retrospective cohort between December 2022 and February 2023 assessed cancer patients complicated with COVID-19 infection in 2 Chinese institutions. Logistic regression analyses were used to compute Odds ratio (OR) and 95%CIs for the association between serum CRP and the incidence of COVID-19 pneumonia in cancer patients. A total of 213 cancer patients with COVID-19 were enrolled. Eighty-six patients (40.4%) developed COVID-19 pneumonia, among which 23 patients (10.8%) progressed to severe cases. Univariate Logistic regression showed that high CRP levels were found to be an unfavorable predictor of COVID-19 outcomes (OR = 17.9, 95%CI: 7.3, 43.6; P < .001). In the multivariate analysis, high CRP levels were associated with a higher incidence rate of COVID-19 pneumonia (OR = 9.8, 95%CI: 2.2, 43.8; P = .003). In the multivariate logistic regression model and smooth curve fitting, we found a correlation between CRP and COVID-19 pneumonia. The serum CRP was associated with the incidence of Omicron variant COVID- 19 pneumonia in cancer patients. Hence, cancer patients with high CRP level maybe need for timely computer tomography examination and more aggressive treatment.

Hospitalisations and Deaths Averted by COVID-19 Vaccination in Navarre, Spain, 2021-2022

In 2021-2022, most of the Spanish population received COVID-19 vaccines and a high proportion of them had SARS-CoV-2 infection. We estimated the rate of hospitalisations and deaths that were averted by risk reduction among vaccinated COVID-19 cases. Hospitalisations and deaths were analysed among COVID-19 cases confirmed in 2021 and 2022 in Navarre, Spain. To calculate the number of prevented outcomes by sex, age, comorbidities, and semester, the difference in the risk of each outcome between unvaccinated and vaccinated cases was multiplied by the number of vaccinated cases. COVID-19 vaccination coverage with any dose reached 88%, 86% with full vaccination, and 56% with a booster dose. The cumulative rates per 1000 inhabitants were 382 COVID-19 confirmed cases, 6.70 hospitalisations, and 1.15 deaths from COVID-19. The estimated rates of prevented events by vaccination were 16.33 hospitalisations and 3.39 deaths per 1000 inhabitants, which was 70.9% and 74.7% of expected events without vaccination, respectively. People aged 80 years and older or with major chronic conditions accounted for the majority of hospitalizations and deaths prevented by COVID-19 vaccination. One hospitalisation and death due to COVID-19 were averted for every 53 and 258 people vaccinated, respectively. The high COVID-19 vaccine effect in reducing the risk of severe outcomes and the high vaccination coverage in risk populations prevented three out of four hospitalisations and deaths due to COVID-19 during a period of intense circulation of SARS-CoV-2.

Changes in the intrinsic severity of severe acute respiratory syndrome coronavirus 2 according to the emerging variant: a nationwide study from February 2020 to June 2022, including comparison with vaccinated populations

BACKGROUND

As the population acquires immunity through vaccination and natural infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), understanding the intrinsic severity of coronavirus disease (COVID-19) is becoming challenging. We aimed to evaluate the intrinsic severity regarding circulating variants of SARS-CoV-2 and to compare this between vaccinated and unvaccinated individuals.

METHODS

With unvaccinated and initially infected confirmed cases of COVID-19, we estimated the case severity rate (CSR); case fatality rate (CFR); and mortality rate (MR), including severe/critical cases and deaths, stratified by age and compared by vaccination status according to the period regarding the variants of COVID-19 and vaccination. The overall rate was directly standardized with age.

RESULTS

The age-standardized CSRs (aCSRs) of the unvaccinated group were 2.12%, 5.51%, and 0.94% in the pre-delta, delta, and omicron period, respectively, and the age-standardized CFRs (aCFRs) were 0.60%, 2.49%, and 0.63% in each period, respectively. The complete vaccination group had lower severity than the unvaccinated group over the entire period showing under 1% for the aCSR and 0.5% for the aCFR. The age-standardized MR of the unvaccinated group was 448 per million people per month people in the omicron period, which was 11 times higher than that of the vaccinated group. In terms of age groups, the CSR and CFR sharply increased with age from the 60 s and showed lower risk reduction in the 80 s when the period changed to the omicron period.

CONCLUSIONS

The intrinsic severity of COVID-19 was the highest in the delta period, with over 5% for the aCSR, whereas the completely vaccinated group maintained below 1%. This implies that when the population is vaccinated, the impact of COVID-19 will be limited, even if a new mutation appears. Moreover, considering the decreasing intrinsic severity, the response to COVID-19 should prioritize older individuals at a higher risk of severe disease.

COVID-19 vaccination prevents a more severe course and treatment with complement inhibitors reduce worsening hemolysis during the Omicron pandemic in patients with PNH: a single-center study

OBJECTIVE

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare acquired disease characterized by chronic complement-mediated hemolysis. The concentrated outbreak of coronavirus disease 2019 (COVID-19) in China after 6 December 2022, provided an opportunity to observe the disease course of PNH during an active Omicron infection epidemic.

PATIENTS AND METHOD

Patients diagnosed with PNH at Peking Union Medical College Hospital (PUMCH) before 6 December 2022, were followed up until 10 April 2023. Clinical data related to coronavirus infection and hemolysis were recorded. Factors influencing the infection and severity rate of Omicron, as well as hemolysis provocation, were analyzed.

RESULTS

In total, 131 patients with PNH were included in this retrospective analysis; 87.8% were infected with Omicron. Among them, 15.7% met the criteria for severity, and 1 patient died (0.87%). No protective factors were identified against Omicron infections. However, patients with severe Omicron infection (n = 18) had a lower vaccination rate than those with non-severe infection (n = 97; p = 0.015). Among those infected (n = 115) with Omicron, there was a significant increase in lactate dehydrogenase (LDH) levels compared with those in the uninfected group (n = 16, p = 0.000). Patients with severe infections (n = 18) had even higher LDH increase rates than those without severe infections (n = 97; p = 0.002). 10 (37.0%) patients treated with complement inhibitors developed breakthrough hemolysis (BTH). Patients treated with complement inhibitors (n = 27) exhibited less severe hemolysis than treatment-naïve patients (n = 104; p = 0.003).

CONCLUSIONS

Omicron infection exacerbates hemolytic attacks in patients with PNH. Vaccination helps mitigate the severity of Omicron infection, and using complement inhibitors reduces hemolysis exacerbation.

International Hepato-Pancreato-Billiary Association (IHPBA) registry study on COVID-19 infections in HPB surgery patients

BACKGROUND

In response to the pandemic, the International Hepato-Pancreato-Biliary Association (IHPBA) developed the IHPBA-COVID Registry to capture data on HPB surgery outcomes in COVID-positive patients prior to mass vaccination programs. The aim was to provide a tool to help members gain a better understanding of the impact of COVID-19 on patient outcomes following HPB surgery worldwide.

METHODS

An online registry updated in real time was disseminated to all IHPBA, E-AHPBA, A-HPBA and A-PHPBA members to assess the effects of the pandemic on the outcomes of HPB procedures, perioperative COVID-19 management and other aspects of surgical care.

RESULTS

One hundred twenty-five patients from 35 centres in 18 countries were included. Seventy-three (58%) patients were diagnosed with COVID-19 preoperatively. Operative mortality after pancreaticoduodenectomy and major hepatectomy was 28% and 15%, respectively, and 2.5% after cholecystectomy. Postoperative complication rates of pancreatic procedures, hepatic interventions and biliary interventions were respectively 80%, 50% and 37%. Respiratory complication rates were 37%, 31% and 10%, respectively.

CONCLUSION

This study reveals a high risk of mortality and complication after HPB surgeries in patient infected with COVID-19. The more extensive the procedure, the higher the risk. Nonetheless, an increased risk was observed across all types of interventions, suggesting that elective HPB surgery should be avoided in COVID positive patients, delaying it at distance from the viral infection.

Challenges and Opportunities Associated with Lifting the Zero COVID-19 Policy in China

Chinese government lifted its "Zero COVID-19" policy in December 2022. The estimated COVDI-19 new cases and deaths after the policy change are 167-279 million (about 12.0% to 20.1% of the Chinese population) and 0.68-2.1 million, respectively. Recent data also revealed continuous drops in fertility rate and historically lowest growth in gross domestic production in China. Thus, balancing COVID-19 control and economic recovery in China is of paramount importance yet very difficult. Supply chain disruption, essential service reduction and shortage of intensive care units have been discussed as the challenges associated with lifting "Zero COVID-19" policy. The additional challenges may include triple epidemic of COVID-19, respiratory syncytial virus and influenza, mental health issues of healthcare providers, care givers and patients, impact on human mobility, lack of robust genomic and epidemiological data and long COVID-19. However, the policy-associated opportunities and other challenges are largely untouched, but warrant attention of and prompt reactions by the policy makers, healthcare providers, public health officials and other stakeholders. The associated benefits are quick reach of herd immunity, boost of economy and businesses activities and increase in social activities. At this moment, we must embrace the policy change, effectively mitigate its associated problems and timely and effectively maximize its associated benefits.

Evolution of illness severity in hospital admissions due to COVID-19, Québec, Canada, January to April 2022

Background

The coronavirus disease 2019 (COVID-19) severity is influenced by multiple factors, such as age, underlying medical conditions, individual immunity, infecting variant, and clinical practice. The highly transmissible Omicron variants resulted in decreased COVID-19 screening capacity, which limited disease severity surveillance.

Objective

To report on the temporal evolution of disease severity among patients admitted to Québec hospitals due to COVID-19 between January 2, 2022, and April 23, 2022, which corresponded to the peak period of hospitalizations due to Omicron.

Methods

Retrospective population-based cohort study of all hospital admissions due to COVID-19 in Québec, between January 2, 2022, and April 23, 2022. Study period was divided into four-week periods, corresponding roughly to January, February, March and April. Regression using Cox and Poisson generalized estimating equations (GEEs) was used to quantify temporal variations in length of stay and risk of complications (intensive care admission or in-hospital death) through time, using the Omicron peak (January 2022) as reference. Measures were adjusted for age, sex, vaccination status, presence of chronic diseases, and clustering by hospital.

Results

During the study period, 9,178 of all 18,272 (50.2%) patients hospitalized with a COVID-19 diagnosis were admitted due to COVID-19. Of these, 1,026 (11.2%) were admitted to intensive care and 1,523 (16.6%) died. Compared to January, the risk of intensive care admission was 25% and 31% lower in March and April respectively, while in-hospital fatality continuously decreased by 45% lower in April. The average length of stay was temporarily lower in March (9%).

Conclusion

Severity of admissions due to COVID-19 decreased in the first months of 2022, when predominant circulating variants were considered to be of similar severity. Monitoring hospital admissions due to COVID-19 can contribute to disease severity surveillance.

Effectiveness of the pre-Omicron COVID-19 vaccines against Omicron in reducing infection, hospitalization, severity, and mortality compared to Delta and other variants: A systematic review

Despite widespread mass rollout programs, the rapid spread of the SARS-CoV-2 Omicron variant called into question the effectiveness of the existing vaccines against infection, hospitalization, severity, and mortality compared to previous variants. This systematic review summarizes and compares the effectiveness of the COVID-19 vaccines, with respect to the above outcomes in adults, children, and adolescents. A comprehensive literature search was undertaken on several databases. Only 51 studies met our inclusion criteria, revealing that the protection from primary vaccination against Omicron infection is inferior to protection against Delta and Alpha infections and wanes faster over time. However, mRNA vaccine boosters were reported to reestablish effectiveness, although to a lower extent against Omicron. Nonetheless, primary vaccination was shown to preserve strong protection against Omicron-associated hospitalization, severity, and death, even months after last dose. However, boosters provide more robust and longer-lasting protection against hospitalizations due to Omicron as compared to only primary series.

COVID-19 in Pakistan: A national analysis of five pandemic waves

OBJECTIVES

The COVID-19 pandemic showed distinct waves where cases ebbed and flowed. While each country had slight, nuanced differences, lessons from each wave with country-specific details provides important lessons for prevention, understanding medical outcomes and the role of vaccines. This paper compares key characteristics from the five different COVID-19 waves in Pakistan.

METHODS

Data was sourced from daily national situation reports (Sitreps) prepared by the National Emergency Operations Centre (NEOC) in Islamabad. We use specific criteria to define COVID-19 waves. The start of each COVID-19 wave is marked by the day of the lowest number of daily cases preceding a sustained increase, while the end is the day with the lowest number of cases following a 7-days decline, which should be lower than the 7 days following it. Key variables such as COVID-19 tests, cases, and deaths with their rates of change to the peak and then to the trough are used to draw descriptive comparisons. Additionally, a linear regression model estimates daily new COVID-19 deaths in Pakistan.

RESULTS

Pakistan saw five distinct waves, each of which displayed the typical topology of a complete infectious disease epidemic. The time from wave-start to peak became progressively shorter, and from wave-peak to trough, progressively longer. Each wave appears to also be getting shorter, except for wave 4, which lasted longer than wave 3. A one percent increase in vaccinations decreased deaths by 0.38% (95% CI: -0.67, -0.08) in wave 5 and the association is statistically significant.

CONCLUSION

Each wave displayed distinct characteristics that must be interpreted in the context of the level of response and the variant driving the epidemic. Key indicators suggest that COVID-19 preventive measures kept pace with the disease. Waves 1 and 2 were mainly about prevention and learning how to clinically manage patients. Vaccination started late during wave 3 and its impact on hospitalizations and deaths became visible in wave 5. The impact of highly virulent strains Alpha/B.1.1.7 and Delta/B.1.617.2 variants during wave 3 and milder but more infectious Omicron/B.1.1.529 during wave 5 are apparent.

Pathogen evolution, prevention/control strategy and clinical features of COVID-19: experiences from China

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported at the end of 2019 as a worldwide health concern causing a pandemic of unusual viral pneumonia and many other organ damages, which was defined by the World Health Organization as coronavirus disease 2019 (COVID-19). The pandemic is considered a significant threat to global public health till now. In this review, we have summarized the lessons learnt during the emergence and spread of SARS-CoV-2, including its prototype and variants. The overall clinical features of variants of concern (VOC), heterogeneity in the clinical manifestations, radiology and pathology of COVID-19 patients are also discussed, along with advances in therapeutic agents.

COVID-19 vaccine uptake among people with HIV: identifying characteristics associated with vaccine hesitancy

People with HIV (PWH) are at increased risk of COVID-19 infection. Both Canadian (NACI) and US (CDC) guidelines recommend that all PWH receive at least 2 doses of COVID-19 vaccine, and a booster. We examined vaccination uptake among PWH in Southern Alberta, Canada. Among adult PWH, we evaluated COVID-19 vaccination uptake between December 2020 and August 2022. Poisson regression models with robust variance (approximating log binomial models) estimated crude and adjusted prevalence ratios (aPR) and 95% confidence intervals (CI) for receiving (1) any vs. no vaccine, and (2) primary series with booster (≥ 3 vaccines) versus primary series without booster. Among 1885 PWH, 10% received no COVID-19 vaccinations, 37% < 3 vaccines and 54% received ≥ 3 vaccines. Females (vs. males) were less likely to receive a vaccine booster. Receiving no COVID-19 vaccines was associated with White ethnicity, unsuppressed HIV viral load (> 200 copies/mL), and using illegal substances. Factors associated with decreased booster uptake included being younger, Black (vs. White) ethnicity, substance use, lower educational attainment, and having an unsuppressed HIV viral load. COVID-19 booster uptake among PWH does not meet vaccine guidelines, and receipt of vaccines is unevenly distributed. Booster uptake is lowest among young females and marginalized individuals. Focused outreach is necessary to close this gap.