COVID-Vaccines in Pregnancy: Maternal and Neonatal Response over the First 9 Months after Delivery.

Vaccination against SARS-CoV-2 has been demonstrated to be safe during gestation. Nevertheless, there are no robust data investigating the entity of maternal antibodies' transmission through the placenta to the newborn and the persistence of the antibodies in babies' serum. The objective of this study is to assess the maternal antibody transmission and kinetics among newborns in the first months of life. Women having received one or two doses of anti-SARS-CoV-2 mRNA-vaccines during pregnancy at any gestational age, and their newborns, were recruited and followed-up over 9 months. Ninety-eight women and 103 babies were included. At birth, we observed a significant positive correlation between maternal and neonatal serum anti-SARS-CoV-2 antibody levels and a significant negative correlation between the time since last dose and antibody levels in mothers with two doses. Over the follow-up, the birth antibody level significantly decreased in time according to the received doses number at 3, 6, and 9 months. During the follow-up, we registered 34 dyad SARS-CoV-2 infection cases. The decreasing trend was slower in the SARS-CoV-2 infection group and among breastfed non-infected babies. Antibodies from maternal anti-SARS-CoV-2 vaccination are efficiently transferred via the placenta and potentially even through breast milk. Among newborns, antibodies show relevant durability in the first months of life.

CMV seroprevalence and coronary CMV-DNA detection in immunocompetent patients with heart diseases.

BACKGROUND: Acute coronary syndromes (ACS) are a major cause of morbidity and mortality. As cytomegalovirus (CMV) may contribute to cardio-vascular (CV) manifestations, we sought to provide a proof-of-concept for the involvement of coronary and/or systemic CMV-reactivation as a possible ACS trigger. METHODS: We prospectively enrolled consecutive patients undergoing a coronary angiography for ACS (acute-cases, N.=136), or non-ACS reasons (chronic-cases, N.=57). Matched coronary and peripheral blood-samples were processed for quantification of CMV-DNAemia (RT-PCR), CMV-IgG/IgM, and CMV-IgG avidity (ELISA). Peripheral-blood samples from 17 healthy subjects were included as controls. RESULTS: Out of the 193 cases included, 18.1% were aged ≤55 years, 92.5% were Central-European, and 100% immunocompetent. CMV-IgG seroprevalence was 91.7% (95%CI: 87.8-95.6), significantly higher than in healthy-controls (52.9% [95%CI: 29.2-76.5]; P<0.001), yet consistent across age-groups (P=0.602), male/females (P=0.765), and acute/chronic-cases (P=0.157). Median (IQR) IgG titers were 110 (84-163) AU/mL, with 0.62 (0.52-0.72) avidity, supporting a long history of infection. No acute CMV infections were found. In 22.6% (n/N.=40/177) of the IgG-positive cases low-level coronary and/or systemic CMV-DNAemia (always <40 copies/mL) was detected. While no differences in peripheral CMV-DNAemia prevalence were observed nor among cases nor controls, coronary CMV-DNAemia was more frequent in acute-cases without modifiable CV risk-factors (n/N.=4/10; 40.0%), than in chronic-cases (n/N.=6/55, 10.9%; P=0.029), or acute-cases with risk-factors (n/N.=16/112, 14.3%; P=0.058). CONCLUSIONS: CMV-IgG seroprevalence was high in patients with heart diseases. CMV-DNAemia can be found, although uncommonly, in coronary circulation during an ACS, with increased prevalence in older subjects and in absence of CV risk-factors, identifying possible areas for novel interventions.

Antibody Response to COVID-19 Booster Vaccination in Healthcare Workers.

Objective: To evaluate the mean increase of anti-S IgG antibody titer between the basal, pre-booster level to the titer assessed 14 days after the booster dose of BNT162b2. Patients and Methods: The RENAISSANCE study is an observational, longitudinal, prospective, population-based study, conducted on healthcare workers of Niguarda Hospital in Milan, Italy who received a BNT162b2 booster dose at least 180 days after their second dose or after positivity for SARS-CoV-2 and accepted to take part in the study. The RENAISSANCE study was conducted from January 1, 2021 through December 28, 2021. Findings: 1,738 subjects were enrolled among healthcare workers registered for the booster administration at our hospital. Overall, 0.4% of subjects were seronegative at the pre-booster evaluation, and 1 subject had a titer equal to 50 AU/ml: none of the evaluated subjects was seronegative after the booster dose. Thus, the efficacy of the booster in our population was universal. Mean increase of pre- to post-booster titer was more significant in subjects who never had SARS-CoV-2 (44 times CI 95% 42-46) compared to those who had it, before (33 times, CI 95% 13-70) or after the first vaccination cycle (12 times, CI 95% 11-14). Differently from sex, age and pre-booster titers affected the post-booster antibody response. Nevertheless, the post-booster titer was very similar in all subgroups, and independent of a prior exposure to SARS-CoV-2, pre-booster titer, sex or age. Conclusion: Our study shows a potent universal antibody response of the booster dose of BNT162b2, regardless of pre-booster vaccine seronegativity.

Polymorphism of the HLA system and weak antibody response to BNT162b2 mRNA vaccine.

The polymorphism of the HLA system has been extensively studied in COVID-19 infection, however there are no data about the role of HLA on vaccine response. We report here the HLA-A, -B, -C, and DRB1 allelic frequencies of n = 111 individuals after BNT162b2 mRNA vaccine, selected on the basis of lower antibody levels (<5% percentile) after the second dose among a total of n = 2569 vaccinees, and compare them with the frequencies of a reference population. We found that differences in the frequencies of the alleles HLA-A*03:01, A*33:03, B*58:01 and at least one haplotype (HLA-A*24:02~C*07:01~B*18:01~DRB1*11:04) are associated with a weaker antibody response after vaccination, together with the age of vaccinees. Our results might suggest a role played by some HLA alleles or haplotypes in antibody production after the BNT162b2 mRNA vaccine, giving insights into the tracking of potentially susceptible individuals across populations. Further studies are needed to better define our exploratory findings and dissect the role of HLA polymorphism on response to anti-COVID-19 vaccines.

Impaired seroconversion after SARS-CoV-2 mRNA vaccines in patients with solid tumours receiving anticancer treatment.

BACKGROUND: Patients with solid tumours have high COVID-19 mortality. Limited and heterogeneous data are available regarding the immunogenicity of SARS-CoV-2 mRNA vaccines in this population. METHODS AND FINDINGS: This is a prospective, single-centre cohort study aiming at evaluating seroconversion in terms of anti-spike antibodies in a population of patients with solid tumours undergoing cancer therapy within 2 months before the second vaccine dose, as compared with a cohort of controls. Subjects who were not SARS-CoV-2 naïve were excluded, and 171 patients were included in the final study population (150 vaccinated with BNT162b2, 87.7%; 21 with mRNA-1273, 12.3%) and compared with 2406 controls. The median follow-up time from the second dose of vaccination was 30 days (12-42; IQR: 26-34). Most patients had metastatic disease (138, 80.7%). Seroconversion rate was significantly lower in cancer patients than in controls (94.2% versus 99.8%, p < 0.001). At univariate logistic regression analysis, Odds ratio (OR) for seroconversion was also reduced in older individuals (>70 years). A multivariate logistic model confirmed cancer as the only significant variable in impairing seroconversion (OR 0.03, p < 0.001). In the cancer population, a multivariate analysis among clinical variables, including the type of cancer treatment, showed ECOG PS > 2 as the only one of impact (OR 0.07, p = 0.012). CONCLUSIONS: There is a fraction of 6% of patients with solid tumours undergoing cancer treatment, mainly with poorer performance status, who fail to obtain seroconversion after SARS-CoV-2 mRNA vaccines. These patients should be considered for enhanced vaccination strategies and carefully monitored for SARS-CoV-2 infection during cancer treatment.

Results of the RENAISSANCE Study: REsponse to BNT162b2 COVID-19 vacciNe-short- And long-term Immune reSponSe evAluatioN in health Care workErs.

OBJECTIVE: To evaluate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) anti-spike (S) IgG antibody production after vaccination with BNT162b2 and the protection from symptomatic breakthrough infections in health care workers. METHODS: This prospective observational study (RENAISSANCE) had as a primary end point the evaluation of serologic response to BNT162b2 14 days after a second dose. SARS-CoV-2 anti-S IgG antibodies were evaluated with LIAISON SARS-CoV-2 TrimericS IgG assay (DiaSorin S.p.A.), which is able to detect the presence of both binding and neutralizing antibodies for trimeric spike glycoprotein. Participants were recruited from February 1, 2021, to February 22, 2021. Occurrence of vaccine breakthrough infections was assessed by reverse transcription-polymerase chain reaction on symptomatic and contact cases up to June 6, 2021. RESULTS: Of 2569 staff evaluated, only 4 were nonresponders (0.16%; 95% CI, 0.04% to 0.41%). All 4 nonresponders were severely immunosuppressed and receiving treatment with mycophenolate mofetil or mycophenolic acid. At 14 days after the second dose, 67.5% (1733) of staff had anti-S IgG titers of 2000 BAU/mL or higher; 19.2% (494), between 1500 and 2000 BAU/mL; 9.8% (251), between 1000 and 1500 BAU/mL; and 3.4% (87), 1000 BAU/mL or lower. Women had a higher probability of having higher titers than men (64.5% [1044/1618] vs 58.3% [410/703]; P=.005). This was confirmed after adjustment for age group (odds ratio, 1.275; 95% CI, 1.062 to 1.531; P=.009). Four months after the end of the vaccination program, only 13 participants (0.26%) had experienced a breakthrough SARS-CoV-2 infection, including 1 nonresponder. This was the only participant requiring hospitalization for severe COVID-19. CONCLUSION: The vaccination campaign among health care workers at the ASST GOM Niguarda has resulted in a marked serologic response and reduction of incident COVID-19 cases. Yet, the lack of protection should not be overlooked in immunocompromised individuals.

Effectiveness of infection-containment measures on SARS-CoV-2 seroprevalence and circulation from May to July 2020, in Milan, Italy.

OBJECTIVE: Through a hospital-based SARS-CoV-2 molecular and serological screening, we evaluated the effectiveness of two months of lockdown and two of surveillance, in Milan, Lombardy, the first to be overwhelmed by COVID-19 pandemics during March-April 2020. METHODS: All subjects presenting at the major hospital of Milan from May-11 to July-5, 2020, underwent a serological screening by chemiluminescent assays. Those admitted were further tested by RT-PCR. RESULTS: The cumulative anti-N IgG seroprevalence in the 2753 subjects analyzed was of 5.1% (95%CI = 4.3%-6.0%), with a peak of 8.4% (6.1%-11.4%) 60-63 days since the peak of diagnoses (March-20). 31/106 (29.2%) anti-N reactive subjects had anti-S1/S2 titers >80 AU/mL. Being tested from May-18 to June-5, or residing in the provinces with higher SARS-CoV-2 circulation, were positively and independently associated with anti-N IgG reactivity (OR [95%CI]: 2.179[1.455-3.264] and 3.127[1.18-8.29], respectively). In the 18 RT-PCR positive, symptomatic subjects, anti-N seroprevalence was 33.3% (95% CI: 14.8%-56.3%). CONCLUSION: SARS-CoV-2 seroprevalence in Milan is low, and in a downward trend after only 60-63 days since the peak of diagnoses. Italian confinement measures were effective, but the risk of contagion remains concrete. In hospital-settings, the performance of molecular and serological screenings upon admission remains highly advisable.

Detection and quantification of SARS-CoV-2 by droplet digital PCR in real-time PCR negative nasopharyngeal swabs from suspected COVID-19 patients.

Since SARS-CoV-2-based disease (COVID-19) spreads as a pandemic, the necessity of a highly sensitive molecular diagnosis that can drastically reduce false negatives reverse transcription PCR (rtPCR) results, raises as a major clinical need. Here we evaluated the performance of a ddPCR-based assay to quantify SARS-CoV-2 titer in 55 suspected COVID-19 cases with negative rtPCR results thanks to in-house ddPCR assay (targeting RdRp and host RNaseP). Samples were collected at ASST-GOM Niguarda between February and May 2020 at hospital admission. Clinical and imaging data were obtained for clinical staging and definition of disease severity. Patients were mainly female (45.5%) with a median age of 73 (57-84) years. ddPCR-based assay detected SARS-CoV-2 genome in nasopharyngeal samples of 19 (34.5%) patients (median viral-load: 128 copies/mL, IQR: 72-345). In 15 of them (78.9%), chest CT showed a classical COVID-19 bilateral interstitial pneumonia; 14 patients (73.7%) showed severe COVID-19 manifestations. ddPCR did not identify any trace of SARS-CoV-2 genome in the respiratory samples of the remaining 36 patients. The serological assay performed in a subgroup of 34 patients at the later stage of illness (from 3 days to 90 days after) confirmed the presence of SARS-CoV-2 antibodies in all patients tested positive for SARS-CoV-2 in ddPCR (100%). Contrariwise, negative tests were observed in 95.0% ddPCR negative patients (P<0.001). Thanks to a ddPCR-based assay, we achieved a rapid and accurate SARS-CoV-2 diagnosis in rtPCR-negative respiratory samples of individuals with COVID-19 suspect, allowing the rapid taking care and correct management of these patients.

Clinical and Analytical Performance of an Automated Serological Test That Identifies S1/S2-Neutralizing IgG in COVID-19 Patients Semiquantitatively.

In the coronavirus (CoV) disease 2019 (COVID-19) pandemic, highly selective serological testing is essential to define exposure to severe acute respiratory syndrome CoV 2 (SARS-CoV-2). Many tests have been developed, yet with variable speeds to first results, and are of unknown quality, particularly when considering the prediction of neutralizing capacity. The LIAISON SARS-CoV-2 S1/S2 IgG assay was designed to measure antibodies against the SARS-CoV-2 native S1/S2 proteins in a standardized automated chemiluminescence assay. The clinical and analytical performances of the test were validated in an observational study using residual samples (>1,500) with a positive or negative COVID-19 diagnosis. The LIAISON SARS-CoV-2 S1/S2 IgG assay proved to be highly selective and specific and offered semiquantitative measures of serum or plasma levels of anti-S1/S2 IgG with neutralizing activity. The assay's diagnostic sensitivities were 91.3% and 95.7% at >5 or ≥15 days from diagnosis, respectively, and 100% when assessed against a neutralizing assay. The assay's specificity ranged between 97% and 98.5%. The average imprecision of the assay was a <5% coefficient of variation. Assay performance at 2 different cutoffs was evaluated to optimize predictive values. The automated LIAISON SARS-CoV-2 S1/S2 IgG assay brings efficient, sensitive, specific, and precise serological testing to the laboratory, with the capacity to test large amounts of samples per day; first results are available within 35 min, with a throughput of 170 tests/hour. The semiquantitative results provided by the test also associate with the presence of neutralizing antibodies and may provide a useful tool for the large-scale screening of convalescent-phase plasma for safe therapeutic use.

Large community-acquired Legionnaires' disease outbreak caused by Legionella pneumophila serogroup 1, Italy, July to August 2018.

In July 2018, a large outbreak of Legionnaires' disease (LD) caused by Legionella pneumophila serogroup 1 (Lp1) occurred in Bresso, Italy. Fifty-two cases were diagnosed, including five deaths. We performed an epidemiological investigation and prepared a map of the places cases visited during the incubation period. All sites identified as potential sources were investigated and sampled. Association between heavy rainfall and LD cases was evaluated in a case-crossover study. We also performed a case-control study and an aerosol dispersion investigation model. Lp1 was isolated from 22 of 598 analysed water samples; four clinical isolates were typed using monoclonal antibodies and sequence-based typing. Four Lp1 human strains were ST23, of which two were Philadelphia and two were France-Allentown subgroup. Lp1 ST23 France-Allentown was isolated only from a public fountain. In the case-crossover study, extreme precipitation 5-6 days before symptom onset was associated with increased LD risk. The aerosol dispersion model showed that the fountain matched the case distribution best. The case-control study demonstrated a significant eightfold increase in risk for cases residing near the public fountain. The three studies and the matching of clinical and environmental Lp1 strains identified the fountain as the source responsible for the epidemic.

Tuberculosis among asylum seekers in Milan, Italy: epidemiological analysis and evaluation of interventions.

In countries of the European Union, tuberculosis (TB) mainly affects marginalised people, including asylum seekers. Migratory flows from high-incidence countries to Italy have increased up to 2017, posing challenges to the national health system. This study sought to assess TB and latent TB infection (LTBI) prevalence among asylum seekers in Milan during the biennium 2016-2017 and to evaluate interventions in place.A two-level active surveillance and screening system was developed for both TB and LTBI. Asylum seekers underwent an initial screening with a tuberculin skin test (TST) and a questionnaire at the receiving sites. At the Regional TB Reference Centre, those with a positive result underwent chest radiography. People aged <35 years with negative chest radiography results underwent further testing by interferon-γ release assay. If results of the assay were positive, LTBI treatment was offered. TB and LTBI prevalence were compared with literature data.A total of 5324 asylum seekers, mostly young (10-39 years; 98%), male (84%) and from sub-Saharan Africa (69%), were enrolled in the study. 69 active TB cases were diagnosed and 863 LTBI-positive individuals were detected. TB prevalence was high (1236 per 100 000 population) and LTBI prevalence was 28%. Despite losses (41%) during the transition from initial screening sites and the diagnostic centre, a good TB cure rate (84%) and optimal LTBI treatment completion (94%) were achieved.Our study shows that TB incidence is high among asylum seekers in Milan and that well-coordinated screening measures are critical for early diagnosis and treatment. It also proves that rolling out successful at-scale interventions for both prophylaxis and disease management is feasible.

First evaluation of QuantiFERON-TB Gold Plus performance in contact screening.

Identifying latently infected individuals is crucial for the elimination of tuberculosis (TB). We evaluated for the first time the performance of a new type of interferon-γ release assay, QuantiFERON-TB Plus (QFT-Plus), which includes an additional antigen tube (TB2), stimulating both CD4+ and CD8+ T-cells in contacts of TB patients.Contacts were screened for latent TB infection by tuberculin skin test, QFT-Plus and QuantiFERON-TB Gold in Tube (QFT-GIT).In 119 TB contacts, the overall agreement between QFT-Plus and QFT-GIT was high, with a Cohen's κ of 0.8. Discordant results were found in 12 subjects with negative QFT-GIT and positive QFT-Plus results. In analyses of markers of TB exposure and test results, the average time spent with the index case was the strongest risk factor for positivity in each of these tests. The difference in interferon-γ production between the two antigen tubes (TB2-TB1) was used as an estimate of CD8+ stimulation provided by the TB2. TB2-TB1 values >0.6 IU·mL-1 were significantly associated with proximity to the index case and European origin.QFT-Plus has a stronger association with surrogate measures of TB exposure than QFT-GIT in adults screened for latent TB infection. Interferon-γ response in the new antigen tube used an indirect estimate of specific CD8+ response correlates with increased Mycobacterium tuberculosis exposure, suggesting a possible role in identifying individuals with recent infection.