Background: Starting from May 31 st, 2023, the local transmission of monkeypox (Mpox) in mainland China began in Beijing. Till now, the transmission characteristics have not been explored. Method: Based on the daily Mpox incidence data in the first three weeks of Beijing (from May 31 st to June 21 st, 2023) , we employed the instant-individual heterogeneity transmission model to simultaneously calculate the effective reproduction number ( R e) and the degree of heterogeneity ( k) of the Beijing epidemic. We additionally simulated the monthly infection size in Beijing from July to September and compared with the reported data to project subsequent transmission dynamics. Results: We estimated R e to be 1.68 [95% HPD:1.12, 2.41], and k to be 2.57 [95% HPD: 0.54, 83.88], suggesting the transmission of Mpox in Beijing was supercritical and didn’t have considerable transmission heterogeneity. We projected that R e fell in the range of 0.95 to 1.0 from July to September, highlighting more efforts needed to further reduce the Mpox transmissibility. Conclusion: Our findings revealed supercritical and homogeneous transmission of the Mpox epidemic in Beijing. Our results may provide reference for understanding and predicting of the on-going Mpox transmission in other regions of China and assess the effect of control measures.

Objective: This study investigated the efficacy of the prophylactic human papillomavirus (HPV) vaccine started at 2009- 2013 in Japan. Materials and Methods: The study involved 1529 eligible women aged 16 to 39 years who visited 11 outpatient clinics for various reasons in Japan. All these patients underwent an examination of HPV genotype and a Pap test using cervical cell samples. Two hundred ninty-nine women (19.6%) received the prophylactic HPV vaccine (bivalent :quadrivalent vaccine ratio = 2:1). Of the 5062 participants in the Japanese Human Papillomavirus Disease Education and Research Survey (J-HERS 2011), which was conducted in the pre-vaccination era, 3236 eligible participants were included as controls. Results: In the present study (J-HERS 2021), highest rate for HPV vaccination (53%) was observed in 22- to 27-year-old patients. Vaccinated ones showed 49% protection against low-grade intraepithelial lesions (LSIL) and atypical squamous cells not excluding high-grade squamous intraepithelial lesions (ASCH) or worse (LSIL/ASCH+), and 100% protection against high-grade squamous intraepithelial lesions (HSIL) or worse (HSIL+). The prevalences of HPV16 and HPV18 infections also significantly decreased (HPV16; 95% and HPV18; 100%), but there were no differences in HPV6 and HPV11 infections by the vaccination. The prevalences of HPV51 and HPV59 increased with vaccination, although these changes were not confirmed in the comparative study with J-HERS 2011. Comparisons between the pre-vaccination period (J-HERS 2011) and post-vaccination period (J-HERS 2021) revealed reduction rates of 43%, 51%, 88%, and 62% were observed for HPV16, HPV18, HPV16/18, and HPV31/58 infections, respectively. Similarly, reduction rates of 62% and 71% for LSIL/ASCH+ and HSIL+, respectively. The reduction rate for LSIL/ASCH+ was 88% in 16- to 21-year-old patients, whereas the rate for HSIL+ was 87% in 28- to 33-year-old patients. C onclusion: Bivalent or quadrivalent vaccines provided 100% protection against high-grade squamous cell lesions (suggestive of CIN2 or CIN3) in young women aged < 39 years at 9 to 12 years after initiation of the first nationwide HPV vaccination program in Japan. Cross-protection against HPV31 and HPV58 is likely to occur, although some HPV type replacements are inconsistent across vaccination regimens. This demonstrates a high effectiveness of HPV vaccine. In contrast, we worry about no reduction of cervical cancer in younger generation (born in 1997-2007) who are rarely vaccinated due to long term suspension of this vaccine recommendation in Japan.

The precise effects of infection and maternal vaccination during pregnancy on the fetus remain uncertain. Therefore, this study aims to investigate the immunological responses triggered by SARS-CoV-2 exposure or vaccination in pregnant women. However, we also evaluated the vertical antibody transmission and the persistence of immunity in infants up to six months post-birth. The study recruited pregnant women admitted for labor and delivery in Fortaleza, Brazil, between January 2021 and March 2022. Participants aged 18 or older with flu-like symptoms were included. Nasopharyngeal swabs and blood samples were collected for COVID-19 testing and antibody detection for the viral Nucleocapsid (N) and Spike (S) of SARS-CoV-2. Participants were categorized as Unvaccinated or Vaccinated, and further divided based on PCR test results. Blood or plasma samples were collected at birth and from infants at six months postpartum. We included 76 mother-infant dyads, 11 in the unvaccinated/PCR-/IgG+, 39 in the unvaccinated/PCR+, 20 in the vaccinated/PCR- and 6 in the vaccinated/PCR+. Analysis of maternal serological profiles showed no significant differences in anti-N IgG levels between unvaccinated and vaccinated groups. However, anti-S IgG titers were significantly higher in vaccinated mothers. The ratio of anti-S IgG antibody transfer from vaccinated mothers to infants was notably higher, especially in the Unvaccinated/PCR+ group compared to the Vaccinated/PCR- group. Furthermore, infants born to vaccinated mothers maintained seroconversion at six months, while those born to unvaccinated mothers did not. Maternal vaccination, particularly during the second trimester, results in a significantly higher transplacental transfer ratio. This leads to elevated anti-S IgG antibody levels in cord blood and infants at six months of age. The study emphasizes the importance of vaccination protocols in optimizing antibody transfer and persistence.

Olfactory dysfunction was one of the most common symptom of infection with the Wuhan strain of SARS-CoV-2 and could persist for several months after symptom onset. The pathogenesis of prolonged olfactory dysfunction (OD) remains poorly understood but probably involves sustained viral replication associated with limited mucosal immune response to the virus. This prospective study was conducted to investigate the potential relationship between nasal SARS-CoV-2 viral load and antibody levels in patients with loss of smell. One hundred and five patients were recruited 2 weeks after presenting with confirmed COVID-19 associated OD. Based on the identification sniffing test performed at enrollment, 52 patients were still anosmic or hyposmic and 53 were normosmic. SARS-CoV-2 was detectable in nasal wash of about 50% of anosmic and normosmic patients. Higher viral load was detected in anosmic patients with lower levels of SARS-CoV-2 specific nasal IgG and IgA. This association was not observed in normosmic patients. No relationship between nasal viral load and antibodies to endemic coronaviruses was observed. SARS-CoV-2 replication in the nasal cavity may be promoted by defective mucosal antibody responses in patients with OD. Boosting mucosal immunity may limit nasal SARS-CoV-2 replication and thereby help in the control of persistent OD.

Comment on Shao et al.’s “risk factors associated with COVID‐19 pneumonia in Chinese patients with pre‐existing interstitial lung disease during the SARS‐CoV‐2 pandemic”Hsiu-Ming Lee 1, Po-Cheng Shih 2,3, James Cheng-Chung Wei, MD, PhD 2,4,51 School of Medicine, China Medical University, Taichung, Taiwan2 Institute of Medicine, Chung Shan Medical University, Taichung, Taiwan3 Department of Allergy, Immunology & Rheumatology, Changhua Christian Hospital, Changhua, Taiwan4 Department of Allergy, Immunology & Rheumatology, Chung Shan Medical University Hospital, Taichung, Taiwan5 Graduate Institute of Integrated Medicine, China Medical University, Taichung, TaiwanHsiu-Ming Lee and Po-Cheng Shih contribute equally.Correspondence： James Cheng-Chung Wei, MD, PhD.Address : No. 110, Sec. 1, Jianguo N. Rd., South District, Taichung City 40201, Taiwan.TEL : ＋886 4 24739595 #34718. (FAX) +886 4 24637389E-mail : [email protected] 0000-0002-1235-0679Word counts: 498Table counts: 0Figure counts: 0Funding Sources : noneConflicts of Interest : The authors declare no conflicts of interest.Dear Editor,We read the article with great interest by Shao et al, where a retrospective study analyzed the risk factors for pneumonia related to the 2019 coronavirus disease (COVID-19) in patients with various types of interstitial lung disease (ILD) caused by SARS-CoV-2 infection. According to Cox’s multivariate analysis, only male gender and the use of corticosteroids emerged as risk factors for developing new coronavirus pneumonia following illness. On the other hand, receiving two to three doses of vaccination proved protective for individuals with preexisting ILD who contracted COVID-19 pneumonia.[1] As a result, it is recommended that patients with preexisting ILD, especially those who are male and using corticosteroids, receive more than two doses of the vaccine for enhanced protection. Since 2019, WHO has reported 770 million confirmed COVID-19 cases and 6.9 million deaths globally.[2] Studies have linked interstitial lung disease to worse COVID-19 outcomes, showing a four-fold mortality increase.[3] Interstitial lung disease includes inflammatory and fibrotic conditions, with incidence rates of 7 to 1,650 per 100,000.[4, 5] In contrast, COVID-19 can also trigger interstitial lung disease.[6] As COVID-19 spreads, global lung disease rates will increase. Identifying risk factors for interstitial lung disease after a COVID-19 diagnosis is crucial for early prevention, resource allocation, and effective management. However, some details in the article still need to be further clarified.First, this paper analyzed several variables in developing pneumonia during COVID-19 infection, including age, sex, vaccination history, common immunosuppressants, antifibrotic agents, and corticosteroids. However, it should be noted that certain risk factors, such as smoking, diabetes mellitus, autoimmune diseases, and recurrent COVID-19 infections, still exhibit a high association with pneumonia and were not included in the analysis.[7-9] Therefore, we recommend that the authors consider incorporating these factors into future similar studies. The paper analyzed corticosteroid use as a potential risk factor but without mentioning the timing of administration. The Centers for Disease Control and Prevention (CDC) recommends steroids for COVID-19 cases beyond a sure severity threshold. Failing to differentiate when they were given may overestimate the proportion of pneumonia cases using steroids, affecting p-values. Some ILD patients use multiple immunosuppressants, impacting immune function and COVID-19 pneumonia risk. While the article lists common medications, it doesn’t analyze the number of patients receiving combined therapy. Therefore, we recommend that future studies assess the risk associated with concurrently using immunosuppressants to understand the implications of combination therapy better.Second, this paper reveals an intriguing shift, as sarcoidosis appears to become a protective factor against pneumonia following a COVID-19 diagnosis. It could be a groundbreaking revelation since the articles consistently state that sarcoidosis is an excessively high-risk factor for severe COVID-19 pneumonia.[10] No literature has delved into this phenomenon, its mechanisms, or potential implications. Given the substantial representation of sarcoidosis patients in this study, we recommended that authors separately analyze its subgroup, examining their disease site, activity, severity, and medication use differences. Furthermore, future research should focus on investigating the interaction mechanisms and conducting comprehensive comparative studies to unlock the full potential of this discovery.References:1. Shao, C., et al., Risk factors associated with COVID-19 pneumonia in Chinese patients with pre-existing interstitial lung disease during the SARS-CoV-2 pandemic. J Med Virol, 2023.95 (9): p. e29098.2. WHO Coronavirus (COVID-19) Dashboard . 2023 [cited 2023 Oct 10, 2023]; Available from:https://covid19.who.int/.3. Valenzuela, C., G. Waterer, and G. Raghu, Interstitial lung disease before and after COVID-19: a double threat? Eur Respir J, 2021.58 (6).4. Shah Gupta, R., et al., Incidence and prevalence of interstitial lung diseases worldwide: a systematic literature review.BMJ Open Respir Res, 2023. 10 (1).5. Lee, C.Y., Interstitial lung disease-From pulmonary perspective to pathogenesis, multidisciplinary approach and treatment. Int J Rheum Dis, 2023. 26 (5): p. 823-824.6. Myall, K.J., et al., Persistent Post-COVID-19 Interstitial Lung Disease. An Observational Study of Corticosteroid Treatment. Ann Am Thorac Soc, 2021. 18 (5): p. 799-806.7. Strzelak, A., et al., Tobacco Smoke Induces and Alters Immune Responses in the Lung Triggering Inflammation, Allergy, Asthma and Other Lung Diseases: A Mechanistic Review. Int J Environ Res Public Health, 2018. 15 (5).8. Wang, W., et al., Clinical characteristics of moderate or severe COVID-19 infection in patients with rheumatic diseases and analysis of risk factors leading to severe disease. Int J Rheum Dis, 2023. 26 (10): p. 1951-1959.9. Batu, E.D. and A. Erden, The outcome of COVID-19 in patients with autoimmune rheumatic diseases: Comparable to the general population or worse? Int J Rheum Dis, 2023. 26 (8): p. 1435-1439.10. Tana, C., et al., Sarcoidosis and COVID-19: At the Cross-Road between Immunopathology and Clinical Manifestation. Biomedicines, 2022.10 (10).

Introduction: In our study, we aimed to evaluate the effect of high dose intravenous anakinra treatment on development of thrombotic events in severe and critical COVID-19 patients. Material and methods: This retrospective observational study was conducted at a tertiary referral center in Aksaray, Turkey. The study population consisted of two groups as follows; the patients receiving high dose intravenous anakinra (anakinra group) added to background therapy and the patients treated with standard of care (SoC) as historical control group. Age, gender, mcHIS scores, and comorbidities such as DM, HT, and CHD of the patients were determined as the variables to be matched. Results: We included 114 patients in SoC and 139 patients in Anakinra group into the study. Development of any thromboembolic event (5% vs 12.3%, p=0.038; OR:4.3) and PTE (2.9% vs 9.6%, p=0.023; OR:5.1) were lower in Anakinra group than SoC. No patient experienced CVA and/or clinically evident DVT both in two arms. After 1:1 PS matching, 88 patients in SoC and 88 patients in Anakinra group were matched and included into the analysis. In survival analysis, development of any thromboembolic event, PTE, and MI were higher in SoC compared to Anakinra. Survival rate was also lower in patients with SoC arm than Anakinra in patients who had any thromboembolic event as well as MI. Conclusion: In our study, development of thrombosis were associated with hyperinflammation in patients with severe and critical COVID-19. Intravenous high-dose anakinra treatment decreases both venous and arterial events in patients with COVID-19.

Introduction : In intensive care units, COVID-19 viral pneumonia patients (VPP) present symptoms similar to those of other patients with non-viral infection (NV-ICU). To better manage VPP, it is therefore interesting to better understand the molecular pathophysiology of viral pneumonia and to search for biomarkers that may clarify the diagnosis. The secretome being a set of proteins secreted by cells in response to stimuli represents an opportunity to discover new biomarkers. Aims : Identify secretomic signatures of VPP with those NV-ICU. Methods : Plasma samples and clinical data from NV-ICU (n=104), VPP (n=30) or healthy donors (HD, n=20) were collected at Nantes Hospital (France) upon admission. Samples were enriched for the low-abundant proteins and analyzed using non-target mass spectrometry. Specifically deregulated proteins (DEP) in VPP versus NV-ICU were selected. Combinations of 2 to 4 DEPs were established. Results : The differences in secretome profiles of the VPP and NV-ICU groups were highlighted. Forty-one DEPs were specifically identified in VPP compared to NV-ICU. Five combinations of 3 proteins with a receiver operating characteristic curve presenting an area under the curve of 95.0% were identified. Conclusion: This study identifies five combinations of candidate biomarkers in VPP compared to NV-ICU that may help distinguish the underlying causal molecular alterations.

Letter to the Editor in response to the article “Willingness to human papillomavirus (HPV) vaccination and influencing factors among male and female university students in China.”

Metabolomics has been increasingly utilized in studying host response to infections and under-standing the progression of multi-system disorders such as COVID-19. The analysis of metabo-lites in response to SARS-CoV-2 infection provides a snapshot of the endogenous host metabo-lism and its role in shaping the interaction with SARS-CoV-2. The current study investigated the metabolic signatures of mortality and severity in COVID-19 patients using a targeted metabo-lomics approach. Blood plasma concentrations were quantified through LC-MS using MxP Quant 500 kit. We utilized Kaplan-Meier survival analysis to investigate the correlation between various metabolic markers and patient outcomes. A comparison of survival rates between individuals with high levels of various metabolites and those with low levels showed statistically significant differences in survival outcomes. We further used four metabolic markers to develop a COVID-19 mortality risk model through the application of multiple machine learning methods. These metabolic predictors can be further validated as potential biomarkers to identify patients at risk of poor outcomes. Finally, integrating machine learning models in metabolome analysis of COVID-19 patients can improve our understanding of disease mortality by providing insight into the relationship between metabolites and survival probability, which can lead to the development of potential therapeutics and clinical risk models.

Nonpharmaceutical interventions (NPIs) against coronavirus disease 2019 (COVID-19) reduced the prevalence of coronavirus among children and influenced the transmission of other viruses. This study investigates the impact of NPIs on human enterovirus (HEV) among children in Hangzhou, China. We collected and analyzed the laboratory results and clinical data of children diagnosed with hand, foot, and mouth disease (HFMD) or herpangina (HA) during the following periods: pre-COVID-19 (January 2019 to December 2019), COVID-19 pandemic (January 2020 to December 2022), and post-COVID-19 (January to August 2023). A total of 38,582 specimens that met the inclusion criteria were enrolled, of which 1,777 (5.58%) tested positive for enterovirus. In comparison to the pre-COVID-19 period, which had 695 (5.63%) HEV-positive specimens, the numbers dramatically decreased to 69 (1.19%), 398 (5.12%), and 112 (1.58%) in 2020, 2021, and 2022, respectively, but significantly increased to 503 (9.00%) in 2023. Seasonal peaks of infections occurred between May and August each year, with positive rates of 10.58%, 25.27%, 31.74%, and 10.97%, respectively. Notably, June and July accounted for half of all cases, with a rate of 57.01%. The difference in the positive rates of HEV infection between males and females was statistically significant (P<0.005), with 5.12% (1,084/21,176) and 4.43% (693/15,629) testing positive, respectively, resulting in a male to female ratio of 1.56:1. Among the same age groups, children aged 3-5 years and 5-7 years had the highest positive rates at 11.03% (342/3,102) and 10.03% (205/2,024), respectively, after synthesizing five years of data. The detection rate of HEV-positive cases increased with age, but after the age of 7, the rate declined. The detected types of HEV indicated that enterovirus 71 (EV-A71) and coxsackievirus A16 (CV-A16) are no longer the two common pathogens causing HFMD and HA. In conclusion, NPIs for COVID-19 are highly effective in reducing the transmission of HEV. However, the relaxation of NPIs results in a resurgence of HEVs, surpassing prepandemic levels. Active awareness and surveillance of the epidemiological characteristics of HEV are essential for preventing, controlling, and managing the development of HFMD and HA, as well as contributing to the development of a multivalent HFMD vaccine.

There has been an explosion in the number of papillomaviruses that have been identified and fully sequenced. Yet only a minute fraction of these has been studied in any detail. Most of our research efforts have focused on the E6 and E7 proteins of “high-risk”, cancer-associated human papillomaviruses (HPVs). Interactions of the high-risk HPV E6 and E7 proteins with cellular targets, the p53 and the retinoblastoma tumor suppressors have been investigated in minute detail. Some have thus questioned if research on papillomaviruses remains an exciting and worthwhile area of investigation. However, fundamentally new insights on the biological activities and cellular targets of the high-risk HPV E6 and E7 proteins have been discovered and previously unstudied HPVs have been associated with human diseases. HPV infections continue to be an important cause of human morbidity and mortality and since there are no antivirals to combat HPV infections, research on HPVs should remain attractive to new investigators and biomedical funding agencies, alike.

Monkeypox (MPOX) is a zoonotic disease with roots tracing back to Western and Central Africa since its initial appearance in humans in 1970. However, the recent upsurge in MPXV outbreaks spanning over 100 nations has sparked substantial concern. In the present investigation, we examine the relative abundance (RA) and relative density (RD) of simple sequence repeats (SSRs) among the global collection of 404 MPOX genomes. Our analysis brings to light substantial shifts in the RA and RD of SSRs as they show transition across temporal spans, from ancient to contemporary lineages. The majority of SSR variations were found in Clades I, IIa, and IIb. Notably, each of the three clades exhibits distinct SSR motifs that are unique to their respective clades. Furthermore, our exploration identifies 26 conserved SSR regions exclusive to MPXV that could be used as molecular or diagnostic markers, and hold potential for vaccine development as well. Moreover, 10 variable SSR hotspot sites were discovered in nine genes with the highest variation in the MPXV genome. Notably, these nine genes have been found to be involved in surface protein synthesis and host regulation, which may have implications for monkeypox pathogenesis and evolution.

The application of metabolomics for studying modifications in host metabolism due to viral infections has proven to be a game-changing approach. Prior to our study, only one other ‘omics’ study has been carried out that investigates the interplay between the host and CCHFV and its subsequent pathogenesis. We employed NMR spectroscopy, given its advantages in terms of reproducibility, minimal sample preparation, and capability to analyze complex biofluids. Our methodology builds upon the proven success of metabolomics in the research of other viral hemorrhagic fevers such as Ebola, Marburg, and Dengue. Our research underlines the critical role of SAH, a metabolite involved in numerous biochemical reactions. We provide new insights into the metabolic alterations occurring in CCHF patients. These alterations not only shed light on the disease’s pathogenesis but also pave the way for potential biomarkers and therapeutic targets. Among all the metabolites detected, S-Adenosyl-L-homocysteine and Carnosine stood out as the most prevalent, warranting further exploration of their roles in CCHFV pathogenesis and their potential as therapeutic targets.

Background: Accurate prediction of SARS-CoV-2 severity remains a challenge. Torque Teno Virus (TTV), recognized as a surrogate marker for cellular immunity in solid organ transplant recipients, holds potential for assessing infection outcomes. Objectives: We investigated whether quantifying TTV in nasopharyngeal samples upon emergency ward (ED) admission could serve as an early predictor of SARS-CoV-2 severity. Study design: Retrospective single-center study in the ED of Saint-Louis Hospital in Paris, France. TTV DNA was quantified in nasopharyngeal swab samples collected for SARS-CoV-2 testing. Results: Among 295 SARS-CoV-2 infected patients, 92 returned home, 160 were admitted to medical wards, and 43 to the intensive care unit. Among 295 SARS-CoV-2 patients, 92 were discharged, 160 hospitalized, and 43 admitted to the intensive care unit (ICU). Elevated TTV loads were observed in ICU patients (Median: 3.02 log copies/mL, interquartile range [IQR]: 2.215-3.825), exceeding those in discharged (2.215, [0; 2.962]) or hospitalized patients (2.24, [0; 3.29]) (p=0.006). Multivariate analysis identified diabetes, obesity, hepatitis, fever, dyspnea, oxygen requirement, and TTV load as predictors of ICU admission. A 2.91 log 10 copies/mL TTV threshold independently predicted ICU admission. Conclusion: Nasopharyngeal TTV quantification in SARS-CoV-2 infected patients is linked to the likelihood of ICU admission and might reflect respiratory immunosuppression.

Early neutralising antibodies against Hepatitis C virus (HCV) and CD8+T cell effector responses can lead to viral clearance. However, these functions alone are not sufficient to protect patients against HCV infection, thus yet undefined additional anti-viral immune mechanisms are required. In recent years, Fc-receptor-dependent antibody effector functions particularly, antibody-dependent cellular phagocytosis (ADCP) was shown to offer immune protection against several RNA viruses. However, its development, and clinical role in patients with HCV infection remain unknown. In this study, we found that patients with chronic GT1a or GT3a HCV infection had significantly higher concentrations of anti-envelop 2 (E2) antibodies, predominantly IgG1 subclass, than patients that cleared the viruses while the latter had antibodies with higher affinities. 97% of the patients with HCV had measurable ADCP of whom patients with chronic disease showed significantly higher ADCP than those who naturally cleared the virus. Epitope mapping studies showed that patients with antibodies that target antigenic domains on the HCV E2 protein that are known to associate with neutralisation function also strongly associated with ADCP, suggesting antibodies with overlapping/dual functions. Correlation studies showed that ADCP significantly correlated with plasma anti-E2 antibody levels and neutralisation function regardless of clinical outcome and genotype of infecting virus while a significant correlation between ADCP and affinity was only evident in patients that cleared the virus. These results suggest ADCP was mostly driven by antibody titre in patients with chronic disease while maintained in clearers due the quality (affinity) of their anti-E2 antibodies despite having lower antibody titres.

Introduction Studies about the duration of the humoral and cellular response following the bivalent booster administration are still scarce. We aimed at assessing the humoral and cellular response in a cohort of healthcare workers that received this booster. Material and methods Blood samples were collected before the administration of the bivalent booster from Pfizer-BioNTech and after 14, 28, 90, and 180 days. Neutralizing antibodies against either the D614G strain, the delta variant, the BA.5 variant, or the XBB.1.5 subvariant were measured. The cellular response was assessed by measurement of the release of interferon gamma (IFNγ) from T cells in response to an in vitro SARS-CoV-2 stimulation. Results A substantial waning of neutralizing antibodies was observed after 6 months (23.1‐fold decrease), especially considering the XBB.1.5 subvariant. The estimated T 1/2 of neutralizing antibodies was 16.1 days (95% CI=10.2–38.4 days). Although most participants still present a robust cellular response after 6 months (i.e., 95%), a significant decrease was also observed compared to the peak response (0.41 versus 0.95 UI/L, p=0.0083). Conclusion A significant waning of the humoral and cellular response was observed after 6 months. These data can also help national competent authorities in their recommendation regarding the administration of an additional booster.

Since the beginning of the pandemic, SARS-CoV-2 has shown a great genomic variability, resulting in the continuous emergence of new variants that has made their global monitoring and study a priority. This work aimed to study the genomic heterogeneity, the temporal origin, the rate of viral evolution and the population dynamics of the main circulating variants (20E.EU1, Alpha and Delta) in Italy, in August 2020-January 2022 period. For phylogenetic analyses, two datasets were evaluated for each variant, the former comprising international genomes and the latter focusing on clusters containing at least 70% of Italian sequences. The international dataset showed 26 (23% Italians, 23% singleton, 54% mixed), 40 (60% mixed, 37.5% Italians, 1 singleton) and 42 (85.7% mixed, 9.5% singleton, 4.8% Italians) clusters with at least one Italian sequence, in 20E.EU1 clade, Alpha and Delta variants, respectively. International clusters presented tMRCAs between 13/06/2020-27/07/2021. R e values showed the highest level between May-June until autumn 2020 in 20E.EU1 clade. The Alpha variant showed an increase in the R e in December 2020, when the highest mean value was estimated. Delta variant presented two peaks: the first between March-May, and the second between June-July 2021. The present work highlighted a different evolutionary dynamic of studied lineages with a high concordance between epidemiological parameters estimation and phylodynamic trends suggesting that the mechanism of replacement of the SARS-CoV-2 variants must be related to a complex of factors involving the transmissibility, as well as the implementation of control measures, and the level of cross-immunization within the population.

Group A rotavirus (RVA) is considered an important cause of acute gastroenteritis (AGE) in all age groups, especially in children. We investigated the epidemiology of RVA in outpatients aged ≤16 years at the Children’s Hospital of Fudan University, Shanghai, China. In this study, 16.6% (246/1482) were infected with RVA. The detection rate of RVA was significantly higher in the year of 2021 (20.3%, 147/725) compared to the year of 2020 (14.5%, 77/531) and 2022 (9.7%, 22/226) ( p=0.000). RVA infection was prevalent in all seasons from 2020 to 2022, with a different monthly distribution observed in different years. Among 246 RVA-positive samples, 14 different RVA genotypes were detected with different frequencies. Overall, G9P[8] (45.5%, 112/246) was the most common RVA genotype, followed by G8P[8] (37.4%, 92/246) and G3P[8] (4.1%, 10/246). The prevalence of G/P combinations varied from 2020 to 2022. G9P[8] was the most circulating genotype in 2020 (68.2%, 15/22) and 2021 (57.8%, 85/147). However, G8P[8] (68.8%, 53/77) suddenly became the most prevalent genotype in 2022 after being first identified in 2020 and prevalent in 2021. The G8 strains detected in the study were all clustered to DS-1-like G8 strains with the closest genetic distance to strains circulating in Southeast Asia. Our study demonstrated the diversity of circulating RVA genotypes in Shanghai. The sudden emergence and high prevalence of unusual G8P[8] strains deserve more concern and indicate the need for continuous surveillance of RVA in children with AGE in the future to refine future vaccine strategy.