Impact of SARS-CoV-2 Omicron and Delta variants in patients requiring intensive care unit (ICU) admission for COVID-19, Northern Italy, December 2021 to January 2022.

This multicenter observational study included 171 COVID-19 adult patients hospitalized in the ICUs of nine hospitals in Lombardy (Northern Italy) from December, 1st 2021, to February, 9th 2022. During the study period, the Delta/Omicron variant ratio of cases decreased with a delay of two weeks in ICU patients compared to that in the community; a higher proportion of COVID-19 unvaccinated patients was infected by Delta than by Omicron whereas a higher rate of COVID-19 boosted patients was Omicron-infected. A higher number of comorbidities and a higher comorbidity score in ICU critically COVID-19 inpatients was positively associated with the Omicron infection as well in vaccinated individuals. Although people infected by Omicron have a lower risk of severe disease than those infected by Delta variant, the outcome, including the risk of ICU admission and the need for mechanical ventilation due to infection by Omicron versus Delta, remains uncertain. The continuous monitoring of the circulating SARS-CoV-2 variants remains a milestone to counteract this pandemic.

Humoral and cellular immune response in patients with hematological disorders after two doses of BNT162b2 mRNA COVID‐19 vaccine: A single‐center prospective observational study (NCT05074706)

Hematological patients at higher risk of severe COVID‐19 were excluded from the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) vaccine trials. In this single‐center observational prospective study (NCT05074706), we evaluate immune response in the hematological patients followed at the Hematological Division of San Gerardo Hospital, Monza (Italy) deemed to be severely immunosuppressed after vaccination with two doses of the BNT162b2 vaccine. Anti‐SARS‐CoV‐2 immunoglobulin G titers above the cutoff value of 33.8 BAU/ml were detected in 303 (80.2%) out of the 378 patients enrolled. Patients with lymphoproliferative disorders had a significant lower probability of immunization (43.2% vs. 88.4%, p < 0.001). Patients treated with anti‐CD20 showed a significantly lower probability of immunization compared to all other treatments (21.4%, p < 0.0001). Among 69 patients who failed seroconversion, 15 patients (22.7%) showed a positive T‐cell response. Patients previously treated with anti‐CD20 were 2.4 times more likely to test positive for T‐cell responses (p = 0.014). Within a follow‐up of 9 months from the second COVID‐19 vaccination, symptomatic SARS‐CoV‐2 infections were reported by 20 patients (5.3%) and four of them required hospitalization. Successful serological or T‐cell‐mediated immunization conferred protection from symptomatic COVID‐19. Patients treated with anti‐CD20 who were not seroconverted after vaccination might still be protected from COVID‐19 due to the T‐cell immune response.

Anti-SARS-CoV-2 IgG antibodies induced by the BNT162b2 mRNA vaccine is age-dependent and influenced by a previous natural SARS-CoV-2 infection.

BACKGROUND AND AIM: our study aimed to investigate the association between anti-SARS-CoV-2 IgG level after two doses of BNT162b2 vaccine and the previously infected/infection-naïve status, age, and gender in a population of health care workers (HCWs). METHODS: all the population of immunocompetent HCWs were vaccinated with two doses of BNT162b2 based on a technical data sheet. SARS-CoV-2 IgG assay was performed 25 to 32 days after the second dose. Anti-SARS-CoV-2 IgG level was used as a categorical variable, since 2080 BAU/ml was the median IgG value. The multivariate logistic regression model included the previously infected/infection-naïve status, age groups, and gender. RESULTS: All HCWs tested were seropositive. The odds ratio (OR) for anti-SARS-CoV-2 IgG> 2080 BAU / ml between previously infected and infection-naïve HCWs was 2.05 [95% CI 1.1-3.8].  Older age groups had lower percentage of HCWs with anti-SARS-CoV-2 IgG> 2080 BAU / mL than younger groups. Finally, no association between gender and IgG level was found. CONCLUSIONS: our study showed an excellent antibody response to vaccination with BNT162b2 after two doses. A significant difference was observed between anti-SARS-CoV-2 IgG level with age and previous SARS-CoV-2 infection status.

Re-emergence of enterovirus D68 in Europe after easing the COVID-19 lockdown, September 2021.

We report a rapid increase in enterovirus D68 (EV-D68) infections, with 139 cases reported from eight European countries between 31 July and 14 October 2021. This upsurge is in line with the seasonality of EV-D68 and was presumably stimulated by the widespread reopening after COVID-19 lockdown. Most cases were identified in September, but more are to be expected in the coming months. Reinforcement of clinical awareness, diagnostic capacities and surveillance of EV-D68 is urgently needed in Europe.

Case Report: Concomitant Massive Cerebral Venous Thrombosis and Internal Iliac Vein Thrombosis Related to Paucisymptomatic COVID-19 Infection.

Thrombotic complications are common in COVID-19 patients, but cerebral venous system involvement, timing after infection, optimal treatment, and long-term outcome are uncertain. We report a case of massive cerebral venous thrombosis and concomitant internal iliac vein thrombosis occurring in the late phase of paucisymptomatic COVID-19 infection. Mild respiratory symptoms, without fever, started 3 weeks before headache and acute neurological deficits. The patient had silent hypoxemia and typical COVID-19 associated interstitial pneumonia. Brain CT scan showed a left parietal hypodense lesion with associated sulcal subarachnoid hemorrhage. CT cerebral venography showed a massive cerebral venous thrombosis involving the right transverse sinus, the right jugular bulb, the superior sagittal sinus, the straight sinus, the vein of Galen, and both internal cerebral veins. Abdominal CT scan showed no malignancy but revealed an asymptomatic right internal iliac vein thrombosis. Both cerebral venous thrombosis and pelvic vein thrombosis were effectively treated with unfractionated heparin started on the day of admission, then shifted to low molecular weight heparin, with a favorable clinical course. Nasopharyngel swab, repeated twice, tested negative for SARS-CoV-2. Serological tests confirmed SARS-CoV-2 infection. Our case supports active surveillance and prevention of thrombotic complications associated with COVID-19, which may affect both peripheral and cerebral venous system. Early initiation of unfractionated heparin may lead to good neurologic outcome.