Reduced Titers of Circulating Anti-SARS-CoV-2 Antibodies and Risk of COVID-19 Infection in Healthcare Workers during the Nine Months after Immunization with the BNT162b2 mRNA Vaccine.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has had a tremendous impact on health services; hundreds of thousands of healthcare workers (HCWs) have died from coronavirus disease 2019 (COVID-19). The introduction of the BNT162b2 mRNA vaccine in Italy provided recipients with significant protection against COVID-19 within one to two weeks after the administration of the second of the two recommended doses. While the vaccine induces a robust T cell response, the protective role of factors and pathways other than those related to memory B cell responses to specific SARS-CoV-2 antigens remains unclear. This retrospective study aimed to evaluate the determinants of serological protection in a group of vaccinated HCWs (n = 793) by evaluating circulating levels of antiviral spike receptor-binding domain (S-RBD) antibodies during the nine-month period following vaccination. We found that 99.5% of the HCWs who received the two doses of the BNT162b2 vaccine developed protective antibodies that were maintained at detectable levels for as long as 250 days after the second dose of the vaccine. Multivariate analysis was performed on anti-S-RBD titers in a subgroup of participants (n = 173) that were evaluated twice during this period. The results of this analysis reveal that the antibody titer observed at the second time point was significantly related to the magnitude of the primary response, the time that had elapsed between the first and the second evaluation, and a previous history of SARS-CoV-2 infection. Of importance is the finding that despite waning antibody titers following vaccination, none of the study participants contracted severe COVID-19 during the observational period.

Impaired clinical outcome and increased postoperative complications in COVID-19 patients undergoing cardiopulmonary bypass

Objective Previous studies reported unfavorable results in COVID-19 patients who underwent cardiac surgery. Complications most frequently observed were respiratory failure and higher incidence of thromboembolic events. We present our single-center experience in patients with perioperative diagnosis of COVID-19 infection undergoing cardiac surgery with extracorporeal circulation. Methods In this observational matched case-control (propensity match 1:2) study, we collected data of patients undergoing open heart cardiac surgery from January 2020 to May 2021, having positive perioperative diagnosis of COVID-19 infection confirmed by polymerase Chain Reaction-PCR (study group). Patients were compared with 56 corresponding controls (control group) who matched for age, sex, body mass index (BMI) and Euro-Score II. Results In the study period 1060 patients underwent cardiac surgery with cardiopulmonary bypass (CPB). Among them, 28 consecutive patients, aged 70.1±9.3 years, had perioperative diagnosis of COVID-19 infection. Four (14%) patients underwent emergency surgery for type-A aortic dissection, 2 (7%) patients died in the Intensive Care Unit for severe respiratory failure, shock and multiple organ failure. Significant bleeding complications occurred in 14 (50%) patients in the study group (vs 6% in the control group, p=<0.05). In the study group, 11 (39%) patients required early surgical reexploration for bleeding, 5 presented cardiac tamponade, 5 (18%) underwent multiple surgical revisions for recurrent bleeding. Three (11%) patients required late chest drainage of a massive sero-hemorrhagic pleural effusion, 1 (4%) presented late postoperative intracranial hemorrhage. Fourteen (50%) patients had severe thrombocytopenia (vs 9% in the control group, p=<0.05). In the study group blood components transfusion and procoagulant drugs administration increased (79% and 78% vs 18% and 11% in the control group, respectively, p=<0.05). In the study group 6 (21%) patients presented postoperative acute renal failure (2% in the control group, p=<0.05), 7 (25%) acute respiratory failure (p=<0.05) requiring prolonged postoperative orotracheal intubation. Sternal dehiscence was observed in 4 (14%) patients in the study group (vs 4% in the control group, p=< 0.05). Complications significantly influenced hospital stay length (20 ± 3.1 vs 8.1 ± 3.9 days, p=< 0.05). In the multivariable logistic regression model the SARS-CoV-2 infection and renal failure were independent factors associated with severe postoperative complications (p=<0.01). Conclusions Clinical outcome of open heart cardiac surgery patients with perioperative COVID-19 infection appears significantly impaired in terms of mortality and postoperative complications. CPB-related inflammatory reaction could likely exacerbate the deleterious effect of COVID-19 on the respiratory and renal systems, as well as on the coagulation pathways. Early and late hemorrhagic complications were very frequent with significantly increased surgical reexplorations for bleeding, a higher incidence of severe thrombocytopenia, of blood components transfusion and procoagulant drugs administration. The increased surgical risk should suggest a cautious attitude in indicating open heart surgery in patients with perioperative COVID-19 infection and surgery should be limited to not postponable or to urgent cases.

Factors Associated with Pre-Vaccination SARS-CoV-2 Infection Risk among Hospital Nurses Facing COVID-19 Outbreak.

The objective of this work was to evaluate the magnitude of COVID-19 spread and the related risk factors among hospital nurses employed in a COVID hospital in Rome, before the beginning of the vaccination programmes commenced in 2021. Participants periodically underwent (every 15-30 days) nasopharyngeal swab and/or blood sample for SARS-CoV-2 IgG examination. From 1 March 2020 to 31 December 2020, we found 162 cases of COVID-19 infection (n = 143 nasopharyngeal swab and n = 19 IgG-positive) in a total of 918 hospital nurses (17.6%). Most SARS-CoV-2-infected hospital nurses were night shift workers (NSWs), smokers, with higher BMI and lower mean age than that of individuals who tested negative. After adjusting for covariates, age (OR = 0.923, 95% C.I. 0.895-0.952), night shift work (OR = 2.056, 95% C.I. 1.320-2.300), smoking status (OR = 1.603, 95% C.I. 1.080-2.378) and working in high-risk settings (OR = 1.607, 95% C.I. 1.036-2.593) were significantly associated with SARS-CoV-2 hospital infection, whereas BMI was not significantly related. In conclusion, we found a high prevalence of SARS-CoV-2 infection among hospital nurses at a Rome COVID hospital in the pre-vaccination period. Smoking, young age, night shift work and high-risk hospital settings are relevant risk factors for hospital SARS-CoV-2 infection; therefore, a close health surveillance should be necessary among hospital nurses exposed to SARS-CoV-2.

Persistence of Anti-S Titre among Healthcare Workers Vaccinated with BNT162b2 mRNA COVID-19.

The COVID-19 pandemic has led to health, social and economic consequences for public health systems. As a result, the development of safe and effective vaccines, in order to contain the infection quickly became a priority. The first vaccine approved by the Italian Agency for Drugs Authorization (AIFA) was the BNT162b2 mRNA vaccine, developed by BioNTech and Pfizer (Comirnaty). Comirnaty contains a molecule called messenger RNA (mRNA), which is a nucleoside-modified RNA that encodes the SARS-CoV-2 spike glycoprotein. Even if data from phase I suggest that vaccine induced antibodies can persist for up to six months following the second shot of BNT vaccine, data regarding the real duration of immunological protection are lacking. In this study, we aimed to evaluate the duration of serological protection by detecting the presence of anti-S-RBD (receptor-binding domain) antibodies for SARS-CoV-2 among a large group of healthcare workers (HCWs) three months after vaccination. 99% of HCWs had a detectable titre of anti-S SARS-CoV-2 antibodies 90 days after the second vaccine shot. Elderly operators showed significantly lower levels of protective antibodies when compared to the younger ones, thus they could become unprotected earlier than other operators.

Evaluation of Immunity for Mumps among Vaccinated Medical Students.

Healthcare workers are considered at higher risk for mumps infection than the general population. Since 2017, the national immunization plan recommended the administration of a dose of measles-mumps-rubella (MMR) vaccine to the healthcare operators who are unable to demonstrate a complete vaccination history or that are seronegative for at least one of the three agents. Regarding mumps infection, based on actual concerns regarding the loss of protection over the years after vaccination, the Advisory Committee on Immunization Practices (ACIP) recommended to administer a third dose of vaccine to operators previously vaccinated with two doses of MMR vaccine who belong to a group at increased risk of mumps infection in the event of an epidemic. This guideline, however, is not currently followed in Italy, resulting in a potential risk for vaccinated operators to become unprotected from mumps over the years. The aim of our study is to evaluate the persistence of a protective antibody level for mumps among medical students vaccinated during infancy or adolescence, at the start of their hospital internship. We retrospectively evaluated mumps-specific IgG levels in a group of medical students, in the period from 1 January to 31 December 2020. We evaluated the persistence of the detectable level of mumps-specific antibodies in relation to their vaccinal status, gender and time elapsed from vaccination. We found that 17.4% (65 subjects) of our sample were seronegative for mumps. The univariate analysis showed a significant difference in serological protection between male and female gender (77.0% vs. 86.2%; p < 0.05 with chi2 test) and between age classes (86.5% vs. 76.4%; p < 0.05 for subjects aged 18-23 years and over 23 years, respectively). Female gender was significantly related to higher serological protection even after adjusting for age classes and number of vaccine doses administered in a multivariate analysis model. Our study shows a substantial percentage of subjects lacking a protective mumps titer among medical students who were vaccinated in childhood. Given the higher risk of infection among those subjects, routine pre-employment screening should be performed among those operators regardless of their vaccination history and a third dose of MMR should be offered to unprotected students.