Aims: To evaluate whether antibodies specific for the vaccinia virus (VV) are still detectable after at least 45 years from immunization. To confirm that VV-specific antibodies are endowed with the capacity to neutralize Mpox virus (MPXV) in vitro. To test a possible role of polyclonal non-specific activation in the maintenance of immunologic memory. Methods: Sera were collected from the following groups: smallpox-vaccinated individuals with or without latent tuberculosis infection (LTBI), unvaccinated donors, and convalescent individuals after MPXV infection. Supernatant of VV- or MPXV-infected Vero cells were inactivated and used as antigens in ELISA or in Western blot (WB) analyses. An MPXV plaque reduction neutralization test (PRNT) was optimized and performed on study samples. VV- and PPD-specific memory T cells were measured by flow cytometry. Results: None of the smallpox unvaccinated donors tested positive in ELISA or WB analysis and their sera were unable to neutralize MPXV in vitro. Sera from all the individuals convalescing from an MPXV infection tested positive for anti-VV or MPXV IgG with high titers and showed MPXV in vitro neutralization capacity. Sera from most of the vaccinated individuals showed IgG anti-VV and anti-MPXV at high titers. WB analyses showed that positive sera from vaccinated or convalescent individuals recognized both VV and MPXV antigens. Higher VV-specific IgG titer and specific T cells were observed in LTBI individuals. Conclusions: ELISA and WB performed using supernatant of VV- or MPXV-infected cells are suitable to identify individuals vaccinated against smallpox at more than 45 years from immunization and individuals convalescing from a recent MPXV infection. ELISA and WB results show a good correlation with PRNT. Data confirm that a smallpox vaccination induces a long-lasting memory in terms of specific IgG and that antibodies raised against VV may neutralize MPXV in vitro. Finally, higher titers of VV-specific antibodies and higher frequency of VV-specific memory T cells in LTBI individuals suggest a role of polyclonal non-specific activation in the maintenance of immunologic memory.

Cancer patients (CPs), being immunosuppressed due to the treatment received or to the disease itself, are more susceptible to infections and their potential complications, showing therefore an increased risk of developing severe COVID-19 compared to the general population. We evaluated the immune responses to anti-SARS-CoV-2 vaccination in patients with solid tumors one year after the administration of the third dose and the effect of cancer treatment on vaccine immunogenicity was assessed. Healthy donors (HDs) were enrolled. Binding and neutralizing antibody (Ab) titers were evaluated using chemiluminescence immunoassay (CLIA) and Plaque Reduction Neutralization Test (PRNT) respectively. T-cell response was analyzed using multiparametric flow cytometry. CPs who were administered three vaccine doses showed lower Ab titers than CPs with four doses and HDs. Overall, a lower cell-mediated response was found in CPs, with a predominance of monofunctional T-cells producing TNF alpha. Lower Ab titers and a weaker T-cell response were observed in CPs without prior SARS-CoV-2 infection when compared to those with a previous infection. While no differences in the humoral response were found comparing immunotherapy and non-immunotherapy patients, a stronger T-cell response in CPs treated with immunotherapy was observed. Our results emphasize the need of booster doses in cancer patients to achieve a level of protection similar to that observed in healthy donors and underlines the importance of considering the treatment received to reach a proper immune response.

The escalating global crisis of antimicrobial-resistant (AMR) bacterial infections, along with the continuous threat of viral outbreaks, poses a serious risk to public health worldwide and underscores the urgent need for innovative therapeutic strategies. In this study, mesoporous silica nanoparticles (MSNs) were successfully synthesized and subsequently functionalized with copper to impart broad-spectrum antimicrobial activity. The oxidation state of copper on the MSN surface was modulated through thermal treatments, allowing the evaluation of its influence on antimicrobial efficacy. The modified MSNs were tested against key bacterial pathogens, including Escherichia coli and Staphylococcus aureus, achieving complete bactericidal activity after 2 h of exposure to E. coli. Moreover, as well as influenza A (H1N1) pdm09, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and MS2 bacteriophage (MS2) were evaluated, reaching an efficiency higher than 80%, 90%, and 97%, respectively. The results indicated that copper-modified MSNs exhibit potent antibacterial and antiviral activity, highlighting their potential as an antibiotic-free alternative for preventing microbial infections while mitigating the development of AMR bacteria.

Dengue virus infection remains a significant public health challenge in endemic regions, with growing evidence of autochthonous transmission in Europe. Assessing serological exposure in high-risk populations such as military personnel deployed to endemic areas is essential to quantify exposure risk and support operational decision-making, particularly regarding pre-deployment counselling and risks associated with secondary infection. We conducted a cross-sectional study involving 1355 members of the Italian Armed Forces, measuring anti-dengue IgG antibodies by ELISA and collecting data on deployment history and exposure risk. Overall, IgG seropositivity was 8.12%, with significantly higher prevalence among individuals reporting travel or deployment to endemic regions (24.71%) compared with non-exposed personnel (4.27%). Seropositivity increased with age and correlated with a CDC-derived cumulative dengue risk score (Spearman’s ρ = 0.299, p < 0.0001). A multivariable logistic regression model including age and exposure risk achieved an AUC of 0.75, while machine-learning models provided complementary predictive assessment, with random forest reaching an AUC of 0.79. These findings indicate substantial anti-dengue IgG seropositivity compatible with previous dengue exposure among Italian military personnel, particularly those deployed to endemic settings. The study highlights the need for targeted surveillance and risk-based preventive strategies, and supports the use of exposure-based models to improve epidemiological assessment and inform vaccination strategies in mobile populations.