Primary SARS-CoV-2 Infections, Re-infections and Vaccine Effectiveness during the Omicron Transmission Period in Healthcare Workers of Trieste and Gorizia (Northeast Italy), 1 December 2021-31 May 2022

Reduced Viral Shedding Time in High-Risk COVID-19 Patients Infected by Omicron and Treated with Paxlovid: A Real-World Study from China

Introduction

The purpose of this study was to compare the viral shedding time in patients infected with the Omicron variant during Paxlovid therapy and conventional therapy and to analyze the effects of Paxlovid on patients infected with COVID-19.

Methods

In this study, the demographic and clinical characteristics and laboratory data of 3159 patients infected with the SARS-CoV-2 Omicron variant treated at Jilin Province People's Hospital were collected and analyzed. A total of 362 patients received Paxlovid therapy, and 2797 patients received conventional therapy. After propensity score matching (PSM), 1086 patients were obtained.

Results

The difference in platelet (PLT) count between the two groups was statistically significant but within the normal range (P < 0.05). CT value revealed that the nucleic acid test results became negative more quickly in the Paxlovid therapy group. Analysis of the Paxlovid therapy group showed that IgG and IgM levels were increased after Paxlovid therapy administration.

Conclusion

The CT value of the Paxlovid therapy group became negative more quickly. This finding suggests that Paxlovid treatment after early diagnosis of the Omicron variant may achieve good therapeutic efficacy.

The impact of SARS-CoV-2 on healthcare workers of a large University Hospital in the Veneto Region: risk of infection and clinical presentation in relation to different pandemic phases and some relevant determinants

Aim

The aim of this study is to evaluate the incidence of SARS-CoV-2 infection and the prevalence of COVID-19-related symptoms in relation to pandemic phases and some relevant variables in a cohort of 8,029 HCWs from one of the largest Italian University Hospitals.

Methods

A single-center retrospective study was performed on data collected during SARS-CoV-2 infection surveillance of HCWs. Cox's multiple regression was performed to estimate hazard ratios of SARS-CoV-2 infection. Logistic multivariate regression was used to assess the risk of asymptomatic infections and the onset of the most frequent symptoms. All analyses were adjusted for sociodemographic and occupational factors, pandemic phases, vaccination status, and previous infections.

Results

A total of 3,760 HCWs resulted positive (2.0%-18.6% across five study phases). The total incidence rate of SARS-CoV-2 infection was 7.31 cases per 10,000 person-days, significantly lower in phase 1 and higher in phases 4 and 5, compared to phase 3. Younger HCWs, healthcare personnel, and unvaccinated subjects showed a higher risk of infection. Overall, 24.5% were asymptomatic infections, with a higher probability for men, physicians, and HCWs tested for screening, fully vaccinated, and those with previous infection. The clinical presentation changed over the phases in relation to vaccination status and the emergence of new variants.

Conclusion

The screening activities of HCWs allowed for the early detection of asymptomatic cases, limiting the epidemic clusters inside the hospital wards. SARS-CoV-2 vaccination reduced infections and symptomatic cases, demonstrating again its paramount value as a preventive tool for occupational and public health.

SARS-CoV-2 Infections, Re-Infections and Clinical Characteristics: A Two-Year Retrospective Study in a Large University Hospital Cohort of Vaccinated Healthcare Workers

At the University Hospital of Bari, during the first year after the start of the mandatory vaccination campaign with BNT162b2 mRNA COVID-19 vaccine, the preliminary results of an observational study showed a significant prevalence of SARS-CoV-2 breakthrough infections (BIs) among healthcare workers (HCWs), but no hospitalization or deaths. In the present study, we extended the observation period (January 2021-January 2023) with the aim of determining the incidence, characteristics and clinical course of SARS-CoV-2 BIs among 6213 HCWs. All HCWs were regularly monitored and screened. To allow return to work after BI, the protocol required one negative nasopharyngeal swab test followed by a medical examination certifying complete clinical recovery. We observed an overall incidence rate of SARS-CoV-2 BIs of 20.2%. Females were most affected, especially in the nurse group compared with doctors and other HCWs (p < 0.0001). Cardiovascular diseases were the most frequent comorbidity (n = 140; 11.4%). The source of infection was non-occupational in 52.4% of cases. Most cases (96.9%) showed minor symptoms and only two cases of hospitalization (one in intensive care unit), 13 cases of re-infection and no deaths were recorded. Our results confirm that SARS-CoV-2 infection can break vaccination protection but the clinical course is favorable.

How European Research Projects Can Support Vaccination Strategies: The Case of the ORCHESTRA Project for SARS-CoV-2

ORCHESTRA ("Connecting European Cohorts to Increase Common and Effective Response To SARS-CoV-2 Pandemic") is an EU-funded project which aims to help rapidly advance the knowledge related to the prevention of the SARS-CoV-2 infection and the management of COVID-19 and its long-term sequelae. Here, we describe the early results of this project, focusing on the strengths of multiple, international, historical and prospective cohort studies and highlighting those results which are of potential relevance for vaccination strategies, such as the necessity of a vaccine booster dose after a primary vaccination course in hematologic cancer patients and in solid organ transplant recipients to elicit a higher antibody titer, and the protective effect of vaccination on severe COVID-19 clinical manifestation and on the emergence of post-COVID-19 conditions. Valuable data regarding epidemiological variations, risk factors of SARS-CoV-2 infection and its sequelae, and vaccination efficacy in different subpopulations can support further defining public health vaccination policies.

Predictors of COVID-19 Severity in Elderly Patients Infected by Omicron in China, 18 December 2022-5 February 2023

Purpose

To analyze the clinical characteristics and prognosis of patients hospitalized with non-severe, severe pneumonia and death in Omicron COVID-19.

Patients and Methods

We collected clinical data from 118 patients with COVID-19 in China from 18 December, 2022 and 5 February, 2023. According to the outcome, the patients were divided into non-severe group, severe group and death group. Subsequently, we statistically analyzed the general condition, clinical manifestations, laboratory parameters, NLR, MLR, PLR and HALP of these groups. We also retrospectively analyzed the possible factors affecting the prognostic regression of patients with COVID-19.

Results

A total of 118 COVID-19 patients were enrolled in this study, including 64 non-severe patients, 38 severe patients and 16 death patients. Compared with the non-severe group, T lymphocytes, B lymphocytes, Th1, Th2, Th17, Treg cells, IgA, IgG, IgM in the severe and death groups decreased more significantly (P<0.05). The levels of myocardial markers, ALT, AST, BUN, Cr, D-dimer, fibrinogen, NLR, MLR and PLR in the severe and death groups were significantly higher than those in the non-severe group (P<0.05). The level of HALP was significantly lower than that of non-severe group (P<0.05). MLR is not only an independent risk factor for the transition from non-severe to severe disease, but also an independent risk factor for predicting the possibility of death in COVID-19 patients.

Conclusion

The analysis of COVID-19 patients in China showed that severe patients were older, more likely to have related complications, lower lymphocyte count, liver and kidney function disorder, glucose and lipid metabolism disorders, myocardial injury, and abnormal coagulation function, suggesting the need for early anticoagulant therapy. In addition, NLR, MLR, PLR and HALP can be used as biomarkers to evaluate the severity and prognosis of COVID-19 patients.

Assessment of the Risk and Symptoms of SARS-CoV-2 Infection Among Healthcare Workers During the Omicron Transmission Period: A Multicentric Study from Four Hospitals of Mainland China

Purpose

The SARS-CoV-2 omicron variant emerged and spread rapidly among the population in the early stage of China's normalized prevention and control in December 2022. Healthcare workers (HCWs) are particularly exposed to SARS-CoV-2, it is important to evaluate the impact of the omicron pandemic on HCWs in China.

Methods

A self-administered online survey was conducted on infected HCWs from four hospitals of Taizhou. A total of 748 HCWs received the survey via DingTalk, and 328 responded to the questionnaire. The risk factors were investigated using univariate and multivariate logistic regression analysis.

Results

By December 20, 2022, 748 HCWs tested positive by PCR, and the infection rate was 11.4% (748/6581). Among 328 respondents, the most common symptoms were cough (88.4%), fever (83.5%), runny nose (77.1%), sore throat (73.2%), headache (70.1%), muscle aches (67.1%), and fatigue (53.4%). 69.8% (229/328) of the participants had five or more major onset symptoms, while no severe case was observed. The multivariate analysis indicated that the poor sleep quality (OR = 2.29, 95% CI: 1.31-4.02, P = 0.004) was an independent risk factor for more major onset symptoms, while wore gloves ≥95% times in working (OR = 0.49, 95% CI: 0.28-0.85, P = 0.011) was significantly related to fewer symptoms. In addition, 239 (72.9%) recipients reported high fever (temperature ≥38.5°C), less common cold (≤3 vs >3 times/year, OR = 2.20, 95% CI: 1.05-4.65, P = 0.038) was significantly associated with high fever.

Conclusion

Our findings imply rapid transmissibility of omicron and multiple-onset symptoms among HCWs. Improved autoimmunity and self-protection measures for HCWs may be helpful in controlling infection and clinical symptoms. Our results provide empirical reference values for improved countermeasures and protective measures for major public health emergencies.

Molnupiravir, Nirmatrelvir/Ritonavir, or Sotrovimab for High-Risk COVID-19 Patients Infected by the Omicron Variant: Hospitalization, Mortality, and Time until Negative Swab Test in Real Life

Background. Several drugs which are easy to administer in outpatient settings have been authorized and endorsed for high-risk COVID-19 patients with mild-moderate disease to prevent hospital admission and death, complementing COVID-19 vaccines. However, the evidence on the efficacy of COVID-19 antivirals during the Omicron wave is scanty or conflicting. Methods. This retrospective controlled study investigated the efficacy of Molnupiravir or Nirmatrelvir/Ritonavir (Paxlovid®) or Sotrovimab against standard of care (controls) on three different endpoints among 386 high-risk COVID-19 outpatients: hospital admission at 30 days; death at 30 days; and time between COVID-19 diagnosis and first negative swab test result. Multivariable logistic regression was employed to investigate the determinants of hospitalization due to COVID-19-associated pneumonia, whereas time to first negative swab test result was investigated by means of multinomial logistic analysis as well as Cox regression analysis. Results. Only 11 patients (overall rate of 2.8%) developed severe COVID-19-associated pneumonia requiring admission to hospital: 8 controls (7.2%); 2 patients on Nirmatrelvir/Ritonavir (2.0%); and 1 on Sotrovimab (1.8%). No patient on Molnupiravir was institutionalized. Compared to controls, hospitalization was less likely for patients on Nirmatrelvir/Ritonavir (aOR = 0.16; 95% CI: 0.03; 0.89) or Molnupiravir (omitted estimate); drug efficacy was 84% for Nirmatrelvir/Ritonavir against 100% for Molnupiravir. Only two patients died of COVID-19 (rate of 0.5%), both were controls, one (a woman aged 96 years) was unvaccinated and the other (a woman aged 72 years) had adequate vaccination status. At Cox regression analysis, the negativization rate was significantly higher in patients treated with both antivirals-Nirmatrelvir/Ritonavir (aHR = 1.68; 95% CI: 1.25; 2.26) or Molnupiravir (aHR = 1.45; 95% CI: 1.08; 1.94). However, COVID-19 vaccination with three (aHR = 2.03; 95% CI: 1.51; 2.73) or four (aHR = 2.48; 95% CI: 1.32; 4.68) doses had a slightly stronger effect size on viral clearance. In contrast, the negativization rate reduced significantly in patients who were immune-depressed (aHR = 0.70; 95% CI: 0.52; 0.93) or those with a Charlson index ≥5 (aHR = 0.63; 0.41; 0.95) or those who had started the respective treatment course 3+ days after COVID-19 diagnosis (aOR = 0.56; 95% CI: 0.38; 0.82). Likewise, at internal analysis (excluding patients on standard of care), patients on Molnupiravir (aHR = 1.74; 95% CI: 1.21; 2.50) or Nirmatrelvir/Ritonavir (aHR = 1.96; 95% CI: 1.32; 2.93) were more likely to turn negative earlier than those on Sotrovimab (reference category). Nonetheless, three (aHR = 1.91; 95% CI: 1.33; 2.74) or four (aHR = 2.20; 95% CI: 1.06; 4.59) doses of COVID-19 vaccine were again associated with a faster negativization rate. Again, the negativization rate was significantly lower if treatment started 3+ days after COVID-19 diagnosis (aHR = 0.54; 95% CI: 0.32; 0.92). Conclusions. Molnupiravir, Nirmatrelvir/Ritonavir, and Sotrovimab were all effective in preventing hospital admission and/or mortality attributable to COVID-19. However, hospitalizations also decreased with higher number of doses of COVID-19 vaccines. Although they are effective against severe disease and mortality, the prescription of COVID-19 antivirals should be carefully scrutinized by double opinion, not only to contain health care costs but also to reduce the risk of generating resistant SARS-CoV-2 strains. Only 64.7% of patients were in fact immunized with 3+ doses of COVID-19 vaccines in the present study. High-risk patients should prioritize COVID-19 vaccination, which is a more cost-effective approach than antivirals against severe SARS-CoV-2 pneumonia. Likewise, although both antivirals, especially Nirmatrelvir/Ritonavir, were more likely than standard of care and Sotrovimab to reduce viral shedding time (VST) in high-risk SARS-CoV-2 patients, vaccination had an independent and stronger effect on viral clearance. However, the effect of antivirals or COVID-19 vaccination on VST should be considered a secondary benefit. Indeed, recommending Nirmatrelvir/Ritonavir in order to control VST in high-risk COVID-19 patients is rather questionable since other cheap, large spectrum and harmless nasal disinfectants such as hypertonic saline solutions are available on the market with proven efficacy in containing VST.

Epidemiological Surveillance Reveals the Rise and Establishment of the Omicron SARS-CoV-2 Variant in Brazil

The introduction of SARS-CoV-2 variants of concern (VOCs) in Brazil has been associated with major impacts on the epidemiological and public health scenario. In this study, 291,571 samples were investigated for SARS-CoV-2 variants from August 2021 to March 2022 (the highest peak of positive cases) in four geographical regions of Brazil. To identify the frequency, introduction, and dispersion of SARS-CoV-2 variants in 12 Brazilian capitals, VOCs defining spike mutations were identified in 35,735 samples through genotyping and viral genome sequencing. Omicron VOC was detected in late November 2021 and replaced the Delta VOC in approximately 3.5 weeks. We estimated viral load differences between SARS-CoV-2 Delta and Omicron through the evaluation of the RT-qPCR cycle threshold (Ct) score in 77,262 samples. The analysis demonstrated that the Omicron VOC has a lower viral load in infected patients than the Delta VOC. Analyses of clinical outcomes in 17,586 patients across the country indicated that individuals infected with Omicron were less likely to need ventilatory support. The results of our study reinforce the importance of surveillance programs at the national level and showed the introduction and faster dispersion of Omicron over Delta VOC in Brazil without increasing the numbers of severe cases of COVID-19.

COVID-19 Incidence and Vaccine Effectiveness in University Staff, 1 March 2020-2 April 2022

Background: University workers undergo intense social interactions due to frequent contact with students and colleagues and lectures in crowdy conditions. The aim of our study was to assess the incidence of COVID-19 infection and vaccine effectiveness in a cohort of workers of the University of Trieste from 1 March 2020 (start of the pandemic) through 2 April 2022. Methods: The University of Trieste implemented a number of public health policies to contain the spread of SARS-CoV-2 on the campus, including prompt contact tracing, enhanced ventilation of all premises, fomites disinfection and mandatory use of face masks indoors. In compliance with the surveillance protocol of the local public health department, university personnel were tested for SARS-CoV-2 by polymerase chain reaction (PCR) on a nasopharyngeal swab on demand, in the event of symptoms consistent with COVID-19 or for contact tracing, following close contact with a confirmed COVID-19 case. The incidence rates of SARS-CoV-2 infections were estimated as number of cases by number of person-days (p-d) at risk. Multivariable Cox proportional hazard regression model was employed to investigate the risk of primary COVID-19 infection, controlling for a number of potential confounders and expressing the risk as the adjusted hazard ratio (aHR) with a 95% confidence interval (95% CI). Results: The incidence of SARS-CoV-2 infection among university staff was lower than that of healthcare workers (HCWs) of the same area. Compared to unvaccinated colleagues (6.55 × 10,000 p-d), the raw incidence of SARS-CoV-2 infection was higher among university workers immunized with one (7.22 × 10,000 p-d) or two (7.48 × 10,000 p-d) doses of COVID-19 vaccines, decreasing in those receiving the booster (1.98 × 1000 p-d). The risk of infection increased only in postgraduate medical trainees (aHR = 2.16; 95% CI: 1.04; 4.48), though this was limited to the Omicron transmission period. After the implementation of the national vaccination campaign against COVID-19, workers immunized with the booster were less likely than unvaccinated workers to be infected by SARS-CoV-2 both before (aHR = 0.10; 95% CI: 0.06; 0.16) and after (aHR = 0.37; 95% CI: 0.27; 0.52) the Omicron transmission period. Vaccine effectiveness of the booster was 90% (=(1-0.10) × 100) before versus 63% (=(1-0.37) × 100) during the Omicron wave, without a significant difference between homologous (three doses of m-RNA vaccines) and heterologous immunization (first two doses of Vaxzevria followed by a third dose of m-RNA vaccine). Conclusions: The incidence of SARS-CoV-2 infection in university staff was lower than that of HCWs of ASUGI, likely because the testing-on-demand schedule inevitably missed the vast majority of asymptomatic infections. Therefore, the observed significantly protective effect of the booster dose in university personnel referred to symptomatic SARS-CoV-2 infections. The infection prevention and control policies implemented by the University of Trieste managed to equalize the biological risk between administrative and teaching staff.

Supporting the Aspecific Physiological Defenses of Upper Airways against Emerging SARS-CoV-2 Variants

The rapid rollout of COVID-19 vaccines in 2021 sparked general optimism toward controlling the severe form of the disease, preventing hospitalizations and COVID-19-associated mortality, and the transmissibility of SARS-CoV-2 infection [...].

Persistence of Symptoms 15 Months since COVID-19 Diagnosis: Prevalence, Risk Factors and Residual Work Ability

Background: A proportion of patients' ailments may last after recovering from acute COVID-19, with episodic and systemic symptoms of unclear etiology potentially involving different organs. Study aim: The aim of this study was to investigate the persistence of symptoms 15 months since COVID-19 diagnosis in patients referring to the post-COVID-19 clinic in Trieste (north-eastern Italy). Methods: Two-hundred-forty-seven patients were medically examined between 8 December 2020-6 April 2021, after a median time of 49 days since first positive swab test for SARS-CoV-2. After a median time of 15 months since COVID-19 diagnosis, the same patients were contacted over the phone and investigated by standardized questionnaire collecting information on any persisting symptoms and work ability index (WAI). Four multivariable logistic regression models were fitted to investigate factors associated with persistence of any respiratory, neurological, dysautonomic, or psychiatric symptoms at first (median time 49 days since COVID-19 diagnosis) as well as second (median 15 months since COVID-19 diagnosis) follow up. A multiple linear regression was also employed to investigate factors associated with higher mean WAI, assessed only at second follow up. Additionally, factors associated with persistence of symptoms 200+ days since COVID-19 diagnosis between first and second follow-up were investigated by multivariable Generalized Estimating Equation (GEE). Results: At first follow up (median time of 49 days since COVID-19 diagnosis) symptoms more frequently reported were fatigue (80.2%), shortness of breath (69.6%), concentration deficit (44.9%), headache (44.9%), myalgia (44.1%), arthralgia (43.3%), and anosmia (42.1%). At second follow-up (median time of 15 months since COVID-19 diagnosis) 75% patients returned to their baseline status preceding COVID-19. At first follow up males were less likely to experience neurological (OR = 0.16; 95% CI: 0.08; 0.35) as well as psychiatric (OR = 0.43; 95% CI: 0.23; 0.80) symptoms as compared to females. At first follow up, the risk of neurological symptoms increased also linearly with age (OR = 1.04; 95% CI: 1.01; 1.08) and pre-existing depression was a major risk factor for persisting dysautonomic (aOR = 6.35; 95% CI: 2.01; 20.11) as well as psychiatric symptoms (omitted estimate). Consistently, at second follow up only females experience psychiatric symptoms, whereas males exhibited significantly higher mean WAI (RC = 0.50; 95% CI: 0.11; 0.88). Additionally, neurological symptoms at second follow up were more likely in patients with pre-existing comorbidities (OR = 4.31; 95% CI: 1.27; 14.7). Finally, persistence of symptoms lasting 200+ days since COVID-19 diagnosis increased linearly with age (OR = 1.03; 95% CI 1.01-1.05) and were more likely in patients affected by pre-existing depression (OR = 2.68; 95% CI 1.60; 4.49). Conclusions: Following a median time of 15 months since first positive swab test, 75% patients with symptoms returned to their baseline health status preceding COVID-19. Females had a significantly lower WAI and were more likely to experience psychiatric symptoms at second follow up (15 months since COVID-19 diagnosis). Furthermore, the risk of symptoms persisting 200+ days since COVID-19 diagnosis increased with history of depression, endorsing the hypothesis that long-COVID-19 symptoms may be at least partially explained by pre-existing psychological conditions. Patient rehabilitation and psychological support may therefore play a key role in caring patients with the so called long COVID-19 syndrome.