Long-Term Benefit of Perlingual Polybacterial Vaccines in Patients with Systemic Autoimmune Diseases and Active Immunosuppression.

INTRODUCTION: We have previously shown that trained-immunity-based vaccines, namely TIbV, significantly reduce the rate of recurrent infections, both of the respiratory tract (RRTI) and urinary tract infections (RUTI) in SAD patients on disease-modifying drugs (DMARDs). OBJECTIVE: We evaluated the frequency of RRTI and RUTI from 2018 to 2021 in those SAD patients that received TIbV until 2018. Secondarily, we evaluated the incidence and clinical course of COVID-19 in this cohort. METHODS: A retrospective observational study was conducted in a cohort of SAD patients under active immunosuppression immunized with TIbV (MV130 for RRTI and MV140 for RUTI, respectively). RESULTS: Forty-one SAD patients on active immunosuppression that were given TIbV up to 2018 were studied for RRTI and RUTI during the 2018-2021 period. Approximately half of the patients had no infections during 2018-2021 (51.2% no RUTI and 43.5% no RRTI at all). When we compared the 3-year period with the 1-year pre-TIbV, RRTI (1.61 ± 2.26 vs. 2.76 ± 2.57; p = 0.002) and RUTI (1.56 ± 2.12 vs. 2.69 ± 3.07; p = 0.010) episodes were still significantly lower. Six SAD patients (four RA; one SLE; one MCTD) with RNA-based vaccines were infected with SARS-CoV-2, with mild disease. CONCLUSIONS: Even though the beneficial protective effects against infections of TIbV progressively decreased, they remained low for up to 3 years, with significantly reduced infections compared to the year prior to vaccination, further supporting a long-term benefit of TIbV in this setting. Moreover, an absence of infections was observed in almost half of patients.

B-cell haematological malignancies and SARS-CoV-2 infection: Could immunological interventions influence the outcome?

B cell haematological malignancies (HMs) have been described as the worst cancer type for concomitant COVID-19 in terms of mortality, with rates up to 65%. This risk factor for COVID-19 cannot only be explained by comorbidities and advanced age of patients, but aggravated by secondary immunodeficiency (SID). We aimed at evaluating the impact of COVID-19 on 86 HM patients with concomitant SID from a single centre. Only 14 HM patients of 86 (16.28%) patients suffered COVID-19, with mortality rate of 7%. When we considered patients according to B-cell defect only or multiple immune defect overlap (B-T-cell/NK cells/complement), patients with immune defect overlap presented 5.30-fold higher risk of COVID-19 than only B cell defect (95% CI, 1.67-17.0) (p = 0.004). Seven (50%) patients were on active IgRT; while five (36%) had received prior mucosal vaccines for respiratory infections. Our results show that modelling SID in HM may contribute to better prediction of infectious risk and to prompt more targeted and timely preventive therapies.

Streptococcus phocae, an emerging pathogen for salmonid culture.

This work describes the characterization of the causal agent of disease outbreaks that, from 1999, occurred repeatedly during the summer months (temperatures higher than 15 degrees C) in Atlantic salmon (Salmo salar) cage-farmed in Chile affecting both smolts and adult fish cultured in estuary and marine waters, reaching in some occasions a cumulative mortality up to 25% of the affected population. Diseased fish showed exophthalmia with accumulation of purulent and haemorrhagic fluid around eyes, and ventral petechial haemorrhages. At necropsy, haemorrhage in the abdominal fat, pericarditis, and enlarged liver, spleen and kidney are common pathological changes. Gram-stained smears revealed the presence of Gram-positive cocci, beta-hemolytic, negative for oxidase and catalase tests. Although biochemical characterization of the isolates using the miniaturized system rapid ID 32 Strep suggested their assignation to genus Gemella, sequencing and RFLP analysis of the 16S rRNA revealed that bacteria associated with the mortalities belong to Streptococcus phocae. Serological studies demonstrated that all the salmon isolates are antigenically homogeneous, which can facilitate the development of preventive measures and, although sharing some antigenical determinants, they belong to a different Lancefield group than the type strain isolated from seals. On the basis of these facts, we conclude that the species S. phocae is an emerging pathogen for salmonid culture in Chile, and it should be included as a new member of the warm water streptococcosis.

Bioadhesives: a biotechnological opportunity

Marine mussels secrete the byssus in order to attach to solid surfaces and to servive under the turbulent effects of waves. The adhesive responsable for this atachment is the polyphenolic protein secreted by the phenol gland in the foot of the animal To purify this adhesive protein form the chilean mussel Mylilus chilensis, a modification of previous procedures has been developed. Accordingly, the protein is differentially precipitated with acetone in the presence of 0.25 N HCl. The purified protein is rich in the amino acids lysine, 3,4-dihydroxyphenylalanine, serine, threonine, proline and hydrozyproline. The protein exhibited strong adhesion to glass and other solid supports. Moreover, its has been found that the adhesive protein can mediate the immobilization of ß-galactosidase to glass. About 75% of the enzyme activity was immobilized under the experimental conditions described. This is the first study reporting the use of the polyphenolic protein to immobilize enzymes