Long-term adaptive response in COVID-19 vaccine recipients and the effect of a booster dose.

We examined the immune response in subjects previously infected with SARS-CoV2 and infection-naïve 9 months after primary 2-dose COVID-19 mRNA vaccination and 3 months after the booster dose in a longitudinal cohort of healthcare workers. Nine months after primary vaccination, previously infected subjects exhibited higher residual antibody levels, with significant neutralizing activity against distinct variants compared to infection-naïve subjects. The higher humoral response was associated with higher levels of receptor binding domain (RBD)-specific IgG+ and IgA+ memory B cells. The booster dose increased neither neutralizing activity, nor the B and T cell frequencies. Conversely, infection-naïve subjects needed the booster to achieve comparable levels of neutralizing antibodies as those found in previously infected subjects after primary vaccination. The neutralizing titer correlated with anti-RBD IFNγ producing T cells, in the face of sustained B cell response. Notably, pre-pandemic samples showed high Omicron cross-reactivity. These data show the importance of the booster dose in reinforcing immunological memory and increasing circulating antibodies in infection-naïve subjects.

A Home-Treatment Algorithm Based on Anti-inflammatory Drugs to Prevent Hospitalization of Patients With Early COVID-19: A Matched-Cohort Study (COVER 2).

Background and Aim: While considerable success has been achieved in the management of patients hospitalized with severe coronavirus disease 2019 (COVID-19), far less progress has been made with early outpatient treatment. We assessed whether the implementation of a home treatment algorithm-designed based on a pathophysiologic and pharmacologic rationale-and including non-steroidal anti-inflammatory drugs, especially relatively selective cyclooxygenase-2 inhibitors and, when needed, corticosteroids, anticoagulants, oxygen therapy and antibiotics-at the very onset of mild COVID-19 symptoms could effectively reduce hospital admissions. Methods: This fully academic, matched-cohort study evaluated outcomes in 108 consecutive consenting patients with mild COVID-19, managed at home by their family doctors between January 2021 and May 2021, according to the proposed treatment algorithm and in 108 age-, sex-, and comorbidities-matched patients on other therapeutic schedules (ClinicalTrials.gov: NCT04854824). The primary outcome was COVID-19-related hospitalization. Analyses were by intention-to-treat. Results: One (0.9%) patient in the "recommended" cohort and 12 (11.1%) in the "control" cohort were admitted to hospital (P = 0.0136). The proposed algorithm reduced the cumulative length of hospital stays by 85% (from 141 to 19 days) as well as related costs (from €60.316 to €9.058). Only 9.8 patients needed to be treated with the recommended algorithm to prevent one hospitalization event. The rate of resolution of major symptoms was numerically-but not significantly-higher in the "recommended" than in the "control" cohort (97.2 vs. 93.5%, respectively; P = 0.322). Other symptoms lingered in a smaller proportion of patients in the "recommended" than in the "control" cohort (20.4 vs. 63.9%, respectively; P < 0.001), and for a shorter period. Conclusion: The adoption of the proposed outpatient treatment algorithm during the early, mild phase of COVID-19 reduced the incidence of subsequent hospitalization and related costs.

Eculizumab in patients with severe coronavirus disease 2019 (COVID-19) requiring continuous positive airway pressure ventilator support: Retrospective cohort study.

BACKGROUND: Complement activation contributes to lung dysfunction in coronavirus disease 2019 (COVID-19). We assessed whether C5 blockade with eculizumab could improve disease outcome. METHODS: In this single-centre, academic, unblinded study two 900 mg eculizumab doses were added-on standard therapy in ten COVID-19 patients admitted from February 2020 to April 2020 and receiving Continuous-Positive-Airway-Pressure (CPAP) ventilator support from ≤24 hours. We compared their outcomes with those of 65 contemporary similar controls. Primary outcome was respiratory rate at one week of ventilator support. Secondary outcomes included the combined endpoint of mortality and discharge with chronic complications. RESULTS: Baseline characteristics of eculizumab-treated patients and controls were similar. At baseline, sC5b-9 levels, ex vivo C5b-9 and thrombi deposition were increased. Ex vivo tests normalised in eculizumab-treated patients, but not in controls. In eculizumab-treated patients respiratory rate decreased from 26.8±7.3 breaths/min at baseline to 20.3±3.8 and 18.0±4.8 breaths/min at one and two weeks, respectively (p<0.05 for both), but did not change in controls. Between-group changes differed significantly at both time-points (p<0.01). Changes in respiratory rate correlated with concomitant changes in ex vivo C5b-9 deposits at one (rs = 0.706, p = 0.010) and two (rs = 0.751, p = 0.032) weeks. Over a median (IQR) period of 47.0 (14.0-121.0) days, four eculizumab-treated patients died or had chronic complications versus 52 controls [HRCrude (95% CI): 0.26 (0.09-0.72), p = 0.010]. Between-group difference was significant even after adjustment for age, sex and baseline serum creatinine [HRAdjusted (95% CI): 0.30 (0.10-0.84), p = 0.023]. Six patients and 13 controls were discharged without complications [HRCrude (95% CI): 2.88 (1.08-7.70), p = 0.035]. Eculizumab was tolerated well. The main study limitations were the relatively small sample size and the non-randomised design. CONCLUSIONS: In patients with severe COVID-19, eculizumab safely improved respiratory dysfunction and decreased the combined endpoint of mortality and discharge with chronic complications. Findings need confirmation in randomised controlled trials.

A simple, home-therapy algorithm to prevent hospitalisation for COVID-19 patients: A retrospective observational matched-cohort study.

BACKGROUND: Effective home treatment algorithms implemented based on a pathophysiologic and pharmacologic rationale to accelerate recovery and prevent hospitalisation of patients with early coronavirus disease 2019 (COVID-19) would have major implications for patients and health system. METHODS: This academic, matched-cohort study compared outcomes of 90 consecutive consenting patients with mild COVID-19 treated at home by their family physicians between October 2020 and January 2021 in Northern and Central Italy, according to the proposed recommendation algorithm, with outcomes for 90 age-, sex-, and comorbidities-matched patients who received other therapeutic regimens. Primary outcome was time to resolution of major symptoms. Secondary outcomes included prevention of hospitalisation. Analyses were by intention-to-treat. FINDINGS: All patients achieved complete remission. The median [IQR] time to resolution of major symptoms was 18 [14-23] days in the 'recommended schedule' cohort and 14 [7-30] days in the matched 'control' cohort (p = 0·033). Other symptoms persisted in a lower percentage of patients in the 'recommended' than in the 'control' cohort (23·3% versus 73·3%, respectively, p<0·0001) and for a shorter period (p = 0·0107). Two patients in the 'recommended' cohort were hospitalised compared to 13 (14·4%) controls (p = 0·0103). The prevention algorithm reduced the days and cumulative costs of hospitalisation by >90%. INTERPRETATION: Implementation of an early home treatment algorithm failed to accelerate recovery from major symptoms of COVID-19, but reduced the risk of hospitalisation and related treatment costs. Given the study design, additional research would be required to consolidate the proposed treatment recommendations. FUNDING: Fondazione Cav.Lav. Carlo Pesenti.

COVID-19 and lombardy: TESTing the impact of the first wave of the pandemic.

BACKGROUND: Italy was the first western country to experience a large Coronavirus Disease 2019 (COVID-19) outbreak and the province of Bergamo experienced one of the deadliest COVID-19 outbreaks in the world. Following the peak of the epidemic in mid-March, the curve has slowly fallen thanks to the strict lockdown imposed by the Italian government on 9th March 2020. METHODS: We performed a cross-sectional study to assess the prevalence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in 423 workers in Bergamo province who returned to the workplace after the end of the Italian lockdown on 5th May 2020. To this end, we performed an enzyme-linked immunosorbent assay (ELISA) to detect the humoral response against SARS-CoV-2 and a nasopharyngeal swab to assess the presence of SARS-CoV-2 RNA by real-time reverse transcription polymerase chain reaction (rRT-PCR). As a secondary aim of the study, we validated a lateral flow immunochromatography assay (LFIA) for the detection of anti-SARS-CoV-2 antibodies. FINDINGS: ELISA identified 38.5% positive subjects, of whom 51.5% were positive for both IgG and IgM, 47.3% were positive only for IgG, but only 1.2% were positive for IgM alone. Only 23 (5.4%) participants tested positive for SARS-CoV-2 by rRT-PCR, although with high cycle thresholds (between 34 and 39), indicating a very low residual viral load that was not able to infect cultured cells. All these rRT-PCR positive subjects had already experienced seroconversion. When the ELISA was used as the comparator, the estimated specificity and sensitivity of the rapid LFIA for IgG were 98% and 92%, respectively. INTERPRETATION: the prevalence of SARS-CoV-2 infection in the province of Bergamo reached 38.5%, significantly higher than has been reported for most other regions worldwide. Few nasopharyngeal swabs tested positive in fully recovered subjects, though with a very low SARS-CoV-2 viral load, with implications for infectivity and discharge policies for positive individuals in the post-pandemic period. The rapid LFIA used in this study is a valuable tool for rapid serologic surveillance of COVID-19 for population studies. FUNDING: The study was supported by Regione Lombardia, Milano Serravalle - Milano Tangenziali S.p.A., Brembo S.p.A, and by MEI System.