Antibody response and risk of reinfection over 2 years among the patients with first wave of COVID-19

OBJECTIVES

To describe the dynamics and factors related to natural and hybrid humoral response against the SARS-CoV-2 and risk of reinfection among first-wave patients.

METHODS

A prospective longitudinal study with periodic serological follow-up after acute onset of all recovered patients with SARS-CoV-2 infection cared in Udine Hospital (March-May 2020). Nucleocapsid (N) protein and spike receptor-binding domain (S-RBD) antibody tests were used to distinguish natural and vaccine-induced response.

RESULTS

Overall, 153 patients (66 men, mean age 56 years) were followed for a median of 27.3 (interquartile range 26.9-27.8) months. Seroreversion was 98.5% (95% CI: 96.8-99.4) for SARS-CoV-2-N IgM at 1 year and 57.4% (95% CI: 51.5-63.5) for SARS-CoV-2-N IgG at 2 years. Initial serological response (hazard ratio [HR]: 0.99, 95% CI: 0.99-0.99, p 0.002 for IgM and HR: 0.97, 95% CI: 0.97-0.98, p < 0.001 for IgG) and severity of acute infection (HR: 0.62, 95% CI: 0.39-0.96, p 0.033 for IgM and HR: 0.60, 95% CI: 0.37-0.99, p < 0.001 for IgG) were independently associated with persistent SARS-CoV-2-N IgM/IgG response. Older age and smoker status were associated with long-term SARS-CoV-2-N IgM and SARS-CoV-2-N IgG, respectively (HR: 0.75, 95% CI: 0.57-0.98, p 0.038; HR: 1.77, 95% CI: 1.19-2.61, p 0.004 respectively). All patients maintained SARS-CoV-2-S-RBD IgG response at 24-month follow-up. Reinfections occurred in 25 of 153 (16.3%) patients, mostly during the omicron circulation. Reinfection rates did not differ significantly between SARS-CoV-2-N IgG seronegative and seropositive patients (14/89, 15.7% vs. 10/62, 16.1%, p 0.947). Unvaccinated patients had higher risk of reinfection (4/7, 57.1% vs. vaccinated 21/146, 14.4%, p 0.014).

DISCUSSION

First-wave patients had durable natural humoral immunity in 40% and anti-S-RBD response in 100% up to 2 years after infection. Natural humoral response alone was not protective against reinfections with omicron SARS-CoV-2 variants, whereas vaccination was effective to reduce the risk of a new infection.

Post-COVID-19 Syndrome 2 Years After the First Wave: The Role of Humoral Response, Vaccination and Reinfection

Background

The aim of this study was to describe the long-term evolution of post-COVID-19 syndrome over 2 years after the onset of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) in survivors of the first wave.

Methods

This prospective study was based on interviews and investigated post-COVID-19 syndrome 6, 12, and 24 months after the disease onset in all adult in- and outpatients with COVID-19 followed at Udine Hospital (Italy) during the first wave (March-May 2020). Humoral response, vaccination status, and reinfection were assessed.

Results

Overall, 230 patients (53.5% female; mean age 54.7 years) were interviewed 2.3 years (standard deviation = 0.11) after acute onset. Post-COVID-19 syndrome was observed in 36.1% of patients (n = 83) at 2 years. The most common persistent symptoms were fatigue (14.4%), rheumatological (14.4%), and psychiatric symptoms (9.6%). Overall, 55.4% (46 of 83) of long haulers searched for healthcare system support and 21 (45.7%) were visited by a specialist. Female gender (odds ratio [OR] = 2.50, P = .005), a proportional increase in the number of symptoms during acute COVID-19 (OR = 1.40, P = .001), and the presence of comorbidities (OR = 1.57, P = .004) were all independent risk factors for post-COVID-19 syndrome. Vaccination and reinfection had no impact on post-COVID-19 syndrome dynamics. The presence of receptor-binding domain (RBD) SARS-CoV-2 immunoglobulin G (IgG) and non-RBD SARS-CoV-2 IgG titers were not associated with the occurrence of post-COVID-19 syndrome.

Conclusions

Two years after COVID-19, the burden of persistent symptoms remains high among in- and outpatients' population infected during the first wave. Post-COVID-19 dynamic does not seem to be influenced by SARS-CoV-2 immunization status and reinfection.

Linezolid Population Pharmacokinetics to Improve Dosing in Cardiosurgical Patients: Factoring a New Drug-Drug Interaction Pathway

Background

Linezolid-induced myelosuppression limits optimal therapy in cardiosurgical patients with deep-seated infections at current doses.

Methods

Adult patients who received a cardiac surgery intervention and linezolid for a documented or presumed serious Gram-positive infection were evaluated. Therapeutic monitoring data, dosing, concomitant medications, and other pertinent laboratory data were collected retrospectively. A population pharmacokinetic model was constructed to identify covariates and test potential drug-drug interactions that may account for interpatient variability. Simulations from the final model identified doses that achieve a target therapeutic trough concentration of 2-8 mg/L.

Results

This study included 150 patients (79.3% male) with sepsis and hospital acquired pneumonia in 71.7% as the primary indication. The population had a median (min-max) age, body weight and estimated glomerular filtration rate (eGFR) of 66 (30–85) years, 76 (45–130) kg and 46.8 (4.9–153.7) mL/min, respectively. The standard linezolid dosage regimen achieved the therapeutic range in only 54.7% of patients. Lower than standard doses were necessary in the majority of patients (77%). A two-compartment Michaellis-Menten clearance model with weight, kidney function, and the number of interacting drugs were identified as covariates that best fit the concentration-time data. Cyclosporine had the greatest effect on lowering the maximum elimination rate (Vmax) of linezolid. Empiric linezolid doses of 300 to 450 mg every 12 hours based on eGFR and the number of interacting medications is suggested by this analysis.

Conclusions

Lower empiric linezolid doses in cardiosurgical patients may avoid toxicities. Confirmatory studies are necessary to verify these potential drug interactions.

Evaluation of qualitative and semi-quantitative cut offs for rapid diagnostic lateral flow test in relation to serology for the detection of SARS-CoV-2 antibodies: findings of a prospective study

Background:

There is limited information to compare the qualitative and semi-quantitative performance of rapid diagnostic tests (RDT) and serology for the assessment of antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, the objective of the study was (a) to compare the efficacy of SARS-CoV-2 antibody detection between RDT and laboratory serology, trying to identify appropriate semi-quantitative cut-offs for RDT in relation with quantitative serology values and to (b) evaluate diagnostic accuracy of RDT compared to the NAAT gold standard in an unselected adult population.

Methods:

SARS-CoV-2 antibodies were simultaneously measured with lateral flow immunochromatographic assays (LFA), the Cellex qSARS-CoV-2 IgG/IgM Rapid Test (by capillary blood), the iFlash-SARS-CoV-2 IgG/IgM chemiluminescent immunoassay (CLIA) (by venous blood) and the nucleic acid amplification test (NAAT) in samples from in- and out-patients with confirmed, suspected and negative diagnosis of coronavirus disease 2019 (COVID-19) attending Udine Hospital (Italy) (March-May 2020). Interpretation of RDT was qualitative (positive/negative) and semi-quantitative based on a chromatographic intensity scale (negative, weak positive, positive).

Results:

Overall, 720 paired antibody measures were performed on 858 patients. The qualitative and semiquantitative agreement analysis performed in the whole sample between LFA and CLIA provided a Kendall’s tau of 0.578 (p < 0.001) and of 0.623 (p < 0.001), respectively, for IgM and IgG. In patients with a diagnosis of COVID-19, accordance between LFA and CLIA was maintained as a function of time from the onset of COVID-19 disease and the severity of disease both for qualitative and semi-quantitative assessments. RDT compared to the NAAT gold standard in 858 patients showed 78.5% sensitivity (95% CI 75.1%-81.7%) and 94.1% specificity (95% CI 90.4%-96.8%), with variable accordance depending on the timing from symptom onset.

Conclusion:

The RDT used in our study can be a non-invasive and reliable alternative to serological tests and facilitate both qualitative and a semi-quantitative antibody detection in COVID-19.

Mental health symptoms one year after acute COVID-19 infection: Prevalence and risk factors

Introduction

Emerging evidence suggests that mental health symptoms in COVID-19 survivors are higher than expected, possibly indicating that such symptoms are more likely to develop post-infection than just persist as a residual component of the acute phase. It is thus imperative to investigate the potential development of a post-COVID mental health syndrome in the longer-term and identify its risk factors.

Material and methods

A prospective study investigated mental health symptoms associated with COVID-19 and its determinants over a 12-month period following the disease onset in all consecutive adult inpatients and outpatients with COVID-19 attending a tertiary referral hospital from March to May 2020.

Results

A total of 479 patients (female, 52.6%) were followed-up for 12 months after COVID-19 onset. Of them, 47.2% were still presenting with at least one symptom. While most symptoms subsided as compared to COVID-19 onset (all p < 0.001), a significant increase was observed only for symptoms of psychiatric disorders (10.2%) and lack of concentration and focus (20%; all p < 0.001). Patients presenting with symptoms related to multiple body systems 12 months after contracting COVID-19 (all p ≤ 0.034) were more likely to suffer from mental health domain-related symptoms at follow-up. Also, a higher risk of presenting with lack of concentration and focus 12 months post infection was found in those suffering of psychiatric symptoms at COVID-19 onset (p = 0.005).

Conclusions

Findings of this study may have important public health implications, as they underlie the increased need for mental health support in COVID-19 survivors.

Low risk of reinfections and relation with serological response after recovery from the first wave of COVID-19

The aim of the study was to assess reinfection rates in relation to long-term antibody dynamics against SARS-CoV-2 after the first wave. A prospective longitudinal study with monthly serological follow-up during the first 4 months, and then at 6, 8, and 10 months after the disease onset of all recovered adult in- and outpatients with COVID-19 attending Udine Hospital (Italy) from March to May 2020. During the follow-up, reinfections were collected. A total of 546 unselected individuals with COVID-19 acquired from March to May 2020 were included (292 female, mean age 53 years). After a median follow-up of 10 months (IQR 6.2–10.4), reinfection occurred in 6 (1.1%) patients, median age of 44.5 years (IQR 33‒49). All had a previous history of mild COVID-19 (all were healthcare workers) and reinfection occurred a median of 9 months (IQR 8.2‒10.2) after the onset of the first episode. Patients with reinfection were either seronegative (2/56, n = 3.6%), seroreverted (2/137, 1.5%), or seropositive (2/353, 0.6%) (p = 0.085). All reinfections were mild (n = 5) or asymptomatic (n = 1). After reinfection, none of patients developed IgM response and only two had a transitory boosted IgG immunization response. In an unselected population after the first wave of COVID-19, after a prolonged observation period (mean 10 months), reinfection was very uncommon; occurred in patients with a previous history of mild infection, mostly with weak or absent serological response; and manifested with mild or asymptomatic clinical presentation.

Vaccine Hesitancy among Italian Patients Recovered from COVID-19 Infection towards Influenza and Sars-Cov-2 Vaccination

We aimed to assess the attitude towards influenza and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations among coronavirus disease 2019 (COVID-19) recovered patients. We performed a cross-sectional study consisting of a standardized telephone interview carried out between September and November 2020 targeting a cohort of adult in- and out-patients that had recovered from COVID-19 after the first wave (March-May 2020) at Udine Hospital (Italy). Overall, 599 people participated (320 female, median age 53 years) and most had experienced an acute COVID-19 with mild illness (409, 68.3%). The majority were hesitant or undecided towards influenza (327, 54.6%) and SARS-CoV-2 (353, 59.2%) vaccines. Older age, public work exposure, and previous 2019 flu shots were the main factors associated with a positive attitude toward both vaccinations (p < 0.05). Being hospitalized during the acute COVID-19 phase was associated with the willingness to get a flu shot (94/272, 34.5%) but not SARS-CoV-2 vaccine (70/244, 28.7%). Vaccine hesitancy is diffuse and multifactorial also among COVID-19 recovered.

Approach to patients with COVID-19 disease: the procedure in Udine

Coronavirus disease 2019 poses a serious threat to public health. The protocol developed at the Azienda Sanitaria Universitaria Friuli Centrale (Italy) is based on clinical data, laboratory tests, chest echography and HRCT. Several therapeutic options are considered, since patients vary in disease severity, evolution and co-morbidities and because so far there are no clear indications about therapeutic strategy based on randomized clinical trial. In this protocol chest echography has a central role in categorizing patient status, follow-up and decision-making.

Hyposmia and Dysgeusia in COVID-19: Indication to Swab Test and Clue of CNS Involvement

Objective

To evaluate the prevalence of hyposmia and dysgeusia in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and their temporal relationship with the onset of other symptoms.

Methods

We performed a retrospective analysis of patients admitted during the month of March 2020 to the nonintensive COVID unit of Udine University Hospital on the basis of a positive swab test and/or of clinical-radiologic signs of SARS-CoV-2 infection. Patients were interviewed with a standardized questionnaire. Clinical and laboratory data were collected. Data were analyzed with descriptive statistics, and results expressed as point estimates and 95% confidence intervals (CIs).

Results

Of 141 patients admitted, 93 were interviewed. Hyposmia and dysgeusia were present in 58 cases (62.4%). In 22.4% of them, olfactory and gustatory impairment clearly preceded systemic symptoms. The presence of active smoking was very limited in both groups: 8.6% in hyposmic vs 2.9% in normosmic patients (odds ratio 3.2; 95% CI 0.3-28.6). Moreover, total leukocytes and neutrophils count were respectively 23% (effect estimate 1.23; 95% CI 1.06-1.42) and 29% (effect estimate 1.29; 95% CI 1.07-1.54) lower in the hyposmic cohort. No difference was found for other inflammatory biomarkers.

Conclusions

Hyposmia and dysgeusia are common in SARS-CoV-2 infection and can precede systemic symptoms. They should be actively searched and prompt close monitoring and isolation until infection is confirmed or disproven. The lower number of total leukocytes and neutrophils in hyposmic patients might indicate an early-phase virus-induced cytopenia.