COVID-19 vaccination and concerns regarding vaccine hesitancy after the termination of the zero-COVID policy in China: A nationwide cross-sectional study

COVID-19 vaccine hesitancy remains prevalent globally. However, national data on this issue in the general population after the termination of the zero-COVID policy in China are limited. In March 2023, we conducted a nationwide cross-sectional survey among Chinese adults using a self-administered questionnaire. Descriptive statistics and multivariate logistic regressions were employed. Among 4,966 participants, 43.8% reported COVID-19 vaccine hesitancy following the end of the zero-COVID policy in China. Higher rates of vaccine hesitancy were associated with being married (married: OR 1.36, 95%CI 1.17-1.57; other marital status: OR 1.86, 95%CI 1.36-2.55), working in healthcare (OR 1.64, 95%CI 1.38-1.96), having both minors and older adults in the household (OR 1.45, 95%CI 1.20-1.75), having no minors and older adults in the household (OR 1.44, 95%CI 1.17-1.77), having chronic diseases (OR 1.42, 95%CI 1.23-1.64), experiencing adverse events post-vaccination (OR 1.39, 95%CI 1.19-1.61), and uncertainty about previous COVID-19 infection (OR 1.45, 95%CI 1.13-1.86). Conversely, participants who had received the influenza vaccine in the past three years (OR 0.62, 95%CI 0.54-0.72), had previously taken the COVID-19 vaccine (OR 0.44, 95%CI 0.32-0.59), and had higher confidence in vaccines (OR 0.63, 95%CI 0.60-0.67) were less likely to exhibit hesitancy. Our findings indicate a significant level of vaccine hesitancy, underscoring the urgent need for tailored public health strategies to address vaccine hesitancy and improve uptake post-zero-COVID policy in China. A comprehensive understanding of public concerns and related factors is essential for developing effective vaccine communication strategies.

Pandemic preparedness through vaccine development for avian influenza viruses

Influenza A viruses pose a significant threat to global health, impacting both humans and animals. Zoonotic transmission, particularly from swine and avian species, is the primary source of human influenza outbreaks. Notably, avian influenza viruses of the H5N1, H7N9, and H9N2 subtypes are of pandemic concern through their global spread and sporadic human infections. Preventing and controlling these viruses is critical due to their high threat level. Vaccination remains the most effective strategy for influenza prevention and control in humans, despite varying vaccine efficacy across strains. This review focuses specifically on pandemic preparedness for avian influenza viruses. We delve into vaccines tested in animal models and summarize clinical trials conducted on H5N1, H7N9, and H9N2 vaccines in humans.

The 2nd China Vaccinology Integrated Innovation & Teaching Development Conference: Promoting the construction of vaccinology discipline system

The 2nd China Vaccinology Integrated Innovation & Teaching Development Conference was held in Sun Yat-sen University, Shenzhen, 18-19, November 2023. Over 200 participants in the field of Vaccinology gathered together to address challenges and issues relevant to vaccine education and training courses, research, and public health programs in China. The conference themed "Promoting the Integrated and Innovative Development of Vaccinology through Collective Efforts." The conference was organized by the China Association of Vaccine (CAV) and hosted by Vaccinology Education Professional Committee of CAV, and School of Public Health (Shenzhen), Sun Yat-sen University. Other partners included the Medical Virology Branch of the Chinese Medical Association, the editorial committee of the Chinese Journal of Preventive Medicine, Human Vaccines & Immunotherapeutics, and the People's Medical Publishing House. The 1st conference was held in Hangzhou, in October 2020.

Adverse events following immunization of co- and separate administration of DTaP-IPV/Hib vaccines: A real-world comparative study

To fully understand the safety of DTaP-IPV/Hib vaccination, we evaluated the differences between DTaP-IPV/Hib co-administration and separate administration of the DTaP, IPV and Hib vaccines (DTaP+IPV+Hib) based on adverse events following immunization (AEFI). All AEFI reported in Hebei Province, China, between 2020 and 2022 were included in this study. The risk difference (RD%), relative risk (RR), and Chi-square value were used to compare the differences in reported rates of AEFI between the DTaP-IPV/Hib and DTaP+IPV+Hib groups. From 2020 to 2022, 130 AEFI cases were reported in Hebei Province after DTaP-IPV/Hib vaccination, corresponding to an AEFI reported rate of 66.9/million doses, which was significantly lower than that for DTaP+IPV+Hib (9836 AEFI with a reported rate of 637.8/million doses). The overall reported rate of non-severe AEFI for DTaP+IPV+Hib vaccines was 9.5 times that of DTaP-IPV/Hib vaccination [95% confidence interval (CI): 8.0, 11.3]. Meanwhile, the reported rate of AEFI among infants aged 0-1 y was 9.8 times higher for DTaP+IPV+Hib than for DTaP-IPV/Hib (95% CI: 8.2, 11.7). DTaP+IPV+Hib vaccination also resulted in higher risks of high fever, localized redness and swelling, localized induration, and allergic rash compared with DTaP-IPV/Hib vaccination. The risk of AEFI, which were mostly mild reaction, was higher after vaccination with DTaP+IPV+Hib than after DTaP-IPV/Hib vaccination.

Knowledge, concerns, and vaccine acceptance related to Mpox (Monkeypox) among university students in North and Northeast China: An online cross-sectional study

The growing number of Mpox cases in China has posed a challenge to public health. The prevalence of men who have sex with men behaviors among students has been consistently increasing each year in China, accompanied by a high frequency of unprotected anal sex. As crowded places, schools are highly likely to cause an Mpox outbreak among students through long-term close contact. Understanding university students' perceptions about Mpox and willingness to vaccinate play a vital role in implementing preventive measures in schools. This study aimed to assess knowledge, concerns, and vaccine acceptance toward Mpox among university students in North and Northeast China. A cross-sectional study was conducted among 3831 university students from seven universities in North and Northeast China between September 10 and September 25, 2023. This study found a relative insufficiency in Mpox knowledge among university students (71.60%), with less than half expressing concern about the Mpox outbreak (39.57%), and the majority exhibiting a positive attitude to vaccination (76.30%). Multivariate regression analysis revealed that a good knowledge level was associated with age, study discipline, education level, and a high level of concern about Mpox. Male, elderly, or highly educated participants had a low level of concern about Mpox. Participants with a high level of knowledge toward Mpox were more likely to have the vaccination willingness. This study might help governments and schools to understand students' Mpox perceptions and vaccination intentions, enabling them to implement effective measures in addressing the issue of inadequate understanding regarding Mpox among university students.

A phase 3 randomized, open-label study evaluating the immunogenicity and safety of concomitant and staggered administration of a live, pentavalent rotavirus vaccine and an inactivated poliomyelitis vaccine in healthy infants in China

This open-label, randomized, phase 3 study in China (V260-074; NCT04481191) evaluated the immunogenicity and safety of concomitant and staggered administration of three doses of an oral, live, pentavalent rotavirus vaccine (RV5) and three doses of an intramuscular, inactivated poliomyelitis vaccine (IPV) in 400 healthy infants. The primary objective was the non-inferiority of neutralizing antibody (nAb) responses in the concomitant- versus the staggered-use groups. Antibody responses were measured at baseline and 1-month post-dose 3 (PD3). Parents/legal guardians recorded adverse events for 30 or 15 d after study vaccinations in the concomitant-use or staggered-use groups, respectively. At PD3, >98% of participants seroconverted to all three poliovirus types, and the primary objective was met as lower bounds of the two-sided 95% CI for between-group difference in nAb seroconversion percentages ranged from - 4.3% to - 1.6%, for all poliovirus types, p < .001. At PD3, geometric mean titers (GMTs) of nAb responses to poliovirus types 1, 2, and 3 in the concomitant-use group and the staggered-use group were comparable; 100% of participants had nAb titers ≥1:8 and ≥1:64 for all poliovirus types. Anti-rotavirus serotype-specific IgA GMTs and participants with ≥3-fold rise in postvaccination titers from baseline were comparable between groups. Administration of RV5 and IPV was well tolerated with comparable safety profiles in both groups. The immunogenicity of IPV in the concomitant-use group was non-inferior to the staggered-use group and RV5 was immunogenic in both groups. No safety concerns were identified. These data support the concomitant use of RV5 and IPV in healthy Chinese infants.

Association between friends' hesitancy and personal COVID-19 vaccine hesitancy among Chinese medical staff

COVID-19 vaccine hesitancy remains problematic among healthcare workers. Social network influences may shape vaccine decision-making, but few studies have examined this in this critical workforce. We assessed the relationship between friends' COVID-19 vaccination attitudes and personal hesitancy among Chinese healthcare personnel. In December 2022-January 2023, a cross-sectional online survey was conducted at a tertiary hospital in China using WeChat. Of the 1832 healthcare personnel who were invited to answer the structured questionnaire, 613 (33.5%) samples had valid data for data analysis. Logistic regression examined the association between friends' hesitancy and participants' own hesitancy, adjusting for confounders. Of 613 healthcare workers included, 266 (43.4%) were hesitant. Those with hesitant friends had 6.34 times higher adjusted odds of hesitating themselves versus those without hesitant friends (95% CI 2.97-13.52). Strong associations persisted across subgroups. Chinese healthcare workers' COVID-19 vaccination hesitancy was highly influenced by perceived friends' attitudes. Fostering pro-vaccine social norms through trusted peer networks could help promote vaccine acceptance in this critical workforce.

Analysis of the implementation effect and evaluation of the vaccine protection effect of the live attenuated varicella vaccine program for school-age children in Bao'an district of Shenzhen,China

The objective of the study is to analyze the implementation effect of the Live Attenuated Varicella Vaccine (VarV) Vaccination Program for eligible children in Bao'an District, Shenzhen, and evaluate the vaccine effectiveness. Children's vaccination data was obtained from the Shenzhen Immunization Planning Information Management System, while varicella case data came from the China Disease Prevention and Control Information System. The Joinpoint regression method examined vaccination rate trends, and a retrospective cohort study assessed vaccine effectiveness. After program implementation, VarV vaccination rates significantly increased, surpassing provincial and national averages. Overall incidence declined 54.6% across age groups, with the largest reductions among 7- and 6-year-olds. One year post-vaccination, single-dose vaccine effectiveness was 91.1% (95% CI: 79.2% to 96.2%). However, two doses remained 91.4% effective(95% CI: 89.1% to 93.2%) after 7 years. Overall, Shenzhen's VarV program achieved positive results. For children under six, routine immunization with two doses of VarV should be strengthened. Furthermore, we recommend that physicians conduct thorough inquiries to ascertain patients' vaccination history and previous varicella infections. This will enable doctors to provide tailored vaccination recommendations based on comprehensive, practical evaluations.

Opportunities and challenges for human papillomavirus vaccination in China

Current estimates of the HPV infection rate in China vary by geographic region (9.6-23.6%), with two age peaks in prevalence in women ≤20-25 years of age and 50-60 years of age. HPV-16, 52 and 58 are the most commonly-detected HPV genotypes in the Chinese population. In China, five HPV vaccines are licensed and several others are undergoing clinical trials. Multiple RCTs have shown the efficacy and safety of the bvHPV (Cervarix), Escherichia coli-produced bvHPV (Cecolin), Pichia pastoris-produced bvHPV (Walrinvax), qvHPV (Gardasil) and 9vHPV (Gardasil-9) vaccines in Chinese populations, including two studies showing long-term efficacy (≥8 years) for the bvHPV and qvHPV vaccines. Real-world data from China are scarce. Although modeling studies in China show HPV vaccination is cost-effective, uptake and population coverage are relatively low. Various policies have been implemented to raise awareness and increase vaccine coverage, with the long-term aim of eliminating cervical cancer in China.

Serological investigation on the prevalence of poliovirus in Guangdong province: A cross-sectional study

In 2019, we conducted a cross-sectional study for polio virus seroprevalence in Guangdong province, China. We assessed the positivity rates of poliomyelitis NA and GMT in serum across various demographic groups, and the current findings were compared with pre-switch data from 2014. Using multistage random sampling method, four counties/districts were randomly selected per city, and within each, one general hospital and two township hospitals were chosen. Healthy individuals coming for medical checkups or vaccination were invited. A total of 1318 individual samples were collected and tested. In non-newborn population, age-dependent positivity rates ranged from 77.8% to 100% for PV1 NA and 70.3% to 98.9% for PV3 NA (p < .01). The lowest GMT values for both types (17.03 and 8.46) occurred in the 20 to <30 years age group, while peak GMTs for PV1 and PV3 were observed in 1 to <2 (340.14) and 0 to <1-year (168.90) age groups, respectively. GMTs for PV1 (P = .002) and PV3 (P = .007) in Eastern Guangdong were lower than those in the other three regions. Male participants showed higher GMTs than females (P = .016 and .033, respectively). In newborn population, both males and females showed higher PV1 NA positivity rates and GMTs compared to PV3 (p < .05). Post-switch PV3 NA positivity rates were higher than pre-switch rates (p = .016). GMTs of both PV1 and PV3 were significantly higher post-switch (p < .001). The positivity rates of NAs and GMTs remain high level, which play an important role in resisting poliomyelitis infection. Effect of the converted immunization program was more pronounced than that before.

Exploring mother-daughter communication and social media influence on HPV vaccine refusal for daughters aged 9-17 years in a cross-sectional survey of 11,728 mothers in China

This study investigated the influences of mother-daughter communication and social media on mothers' HPV vaccine refusal for their daughters aged 9-17. A cross-sectional online survey among 11,728 mothers of girls aged 9-17 in Shenzhen, China was implemented between July and October 2023. Multi-level logistic regression models were fitted. Among 11,728 participants, 43.2% refused to have their daughters receive an HPV vaccination. In multivariate analysis, more openness in the mother-daughter communication (AOR: 0.99, 95%CI: 0.98, 0.99), perceived more positive outcomes of mother-daughter communication (AOR: 0.77, 95%CI: 0.75, 0.79), higher frequency of exposure to testimonials about daughters' HPV vaccination (AOR: 0.81, 95%CI: 0.78, 0.85) and information encouraging parents to vaccinate their daughters against HPV on social media (AOR: 0.76, 95%CI: 0.73, 0.79), and thoughtful consideration of the veracity of the information specific to HPV vaccines (AOR: 0.80, 95%CI: 0.77, 0.83) were associated with lower vaccine refusal. Mothers who were not the main decision-makers of daughters' HPV vaccination (AOR: 1.28 to 1.46), negative outcome expectancies of mother-daughter communication (AOR: 1.06, 95%CI: 1.04, 1.08), and mothers' HPV vaccine refusal (AOR: 2.81, 95%CI: 2.58, 3.06) were associated with higher vaccine refusal for their daughters. The level of mothers' HPV vaccine refusal for their daughters was high in China. Openness and outcome expectancies of mother-daughter communication and information exposure on social media were considered key determinants of HPV vaccine refusal for daughters. Future HPV vaccination programs should consider these interpersonal factors.

Acceptance and willingness to pay for DTaP-HBV-IPV-Hib hexavalent vaccine among parents: A cross-sectional survey in China

DTaP-HBV-IPV-Hib hexavalent vaccine has been used in high-income countries for many years to prevent diphtheria, tetanus, pertussis, hepatitis B, poliomyelitis, and invasive Haemophilus influenzae type b disease. Currently, no hexavalent vaccines have been approved for use in China. Evidence of parental acceptance and interest in hexavalent vaccines can help policy makers and manufacturers make decisions about entering the vaccine market and the immunization program in China. We measured parental acceptance and willingness-to-pay (WTP) for a hexavalent vaccine to provide such evidence. We conducted a cross-sectional survey of children's caregivers in 16 vaccination clinics in seven cities in China and obtained information on socio-demographics, knowledge of disease, confidence in vaccines, previous vaccination experience, and acceptance of and WTP for hexavalent vaccine. Multivariate logistic regression was used to determine factors influencing acceptance, and multivariate tobit regression was used to identify factors impacting WTP. Between April 28 and June 30, 2023, a total of 581 parents of children aged 0-6 years participated in the survey; 435 (74.87%, 95% CI:71.3%-78.4%) parents indicated acceptance of hexavalent vaccine. Residence location, parents' education level, experience paying for vaccination, and disease knowledge scores were key factors affecting parents' choices for vaccination. Mean (SD) and median (IQR) willingness to pay for full 4-dose course vaccination were 2266.66 (1177.1) CNY and 2400 (1600-2800) CNY. Children's age (p < .001), parents' education level (p = .024), and perceived price barriers (p < .001) were significantly associated with WTP. Parents have high acceptance and willingness to pay for hexavalent vaccine. The less money parents have to pay out of pocket, the more willing they can be to accept the vaccine. Therefore, acceptance may increase even further if the vaccine is covered by medical insurance, provided free of charge by the government, or if its price is reduced. Our results provide reference for optimizing and adjusting immunization strategies in China.

SARS-CoV-2 omicron BA.2.87.1 exhibits higher susceptibility to serum neutralization than EG.5.1 and JN.1

As SARS-CoV-2 continues to spread and mutate, tracking the viral evolutionary trajectory and understanding the functional consequences of its mutations remain crucial. Here, we characterized the antibody evasion, ACE2 receptor engagement, and viral infectivity of the highly mutated SARS-CoV-2 Omicron subvariant BA.2.87.1. Compared with other Omicron subvariants, including EG.5.1 and the current predominant JN.1, BA.2.87.1 exhibits less immune evasion, reduced viral receptor engagement, and comparable infectivity in Calu-3 lung cells. Intriguingly, two large deletions (Δ15-26 and Δ136-146) in the N-terminal domain (NTD) of the spike protein facilitate subtly increased antibody evasion but significantly diminish viral infectivity. Collectively, our data support the announcement by the USA CDC that the public health risk posed by BA.2.87.1 appears to be low.

Emergence and ongoing outbreak of ST80 vancomycin-resistant Enterococcus faecium in Guangdong province, China from 2021 to 2023: a multicenter, time-series and genomic epidemiological study

BACKGROUND

Surveillance systems revealed that the prevalence of vancomycin-resistant Enterococcus faecium (VREfm) has increased. We aim to investigate the epidemiological and genomic characteristics of VREfm in China.

METHODS

We collected 20,747 non-redundant E. faecium isolates from inpatients across 19 hospitals in six provinces between January 2018 and June 2023. VREfm was confirmed by antimicrobial susceptibility testing. The prevalence was analyzed using changepoint package in R. Genomic characteristics were explored by whole-genome sequencing.

RESULTS

5.59% (1159/20,747) of E. faecium isolates were resistant to vancomycin. The prevalence of VREfm increased in Guangdong province from 5% before 2021 to 20-50% in 2023 (p < 0.0001), but not in the other five provinces. Two predominant clones before 2021, ST17 and ST78, were substituted by an emerging clone, ST80, from 2021 to 2023 (88.63%, 195/220). All ST80 VREfm from Guangdong formed a single lineage (SC11) and were genetically distant from the ST80 VREfm from other countries, suggesting a regional outbreak. All ST80 VREfm in SC11 carried a new type of plasmid harbouring a vanA cassette, which was embedded in a Tn1546-like structure flanked by IS1678 and ISL3. However, no conjugation-related gene was detected and no transconjugant was obtained in conjugation experiment, indicating that the outbreak of ST80 VREfm could be attributed to clonal transmission.

CONCLUSIONS

We revealed an ongoing outbreak of ST80 VREfm with a new vanA-harbouring plasmid in Guangdong, China. This clone has also been identified in other provinces and countries, foreboding a risk of wider spreading shortly. Continuous surveillance is needed to inform public health interventions.

Comparative immunogenicity of monovalent and bivalent adenovirus vaccines carrying spikes of early and late SARS-CoV-2 variants

The continuous emergence of highly immune-evasive SARS-CoV-2 variants has challenged vaccine efficacy. A vaccine that can provide broad protection is desirable. We evaluated the immunogenicity of a series of monovalent and bivalent adenovirus-vectored vaccines containing the spikes of Wildtype (WT), Beta, Delta, Omicron subvariants BA.1, BA.2, BA.2.12.1, BA.2.13, BA.3, BA.5, BQ.1.1, and XBB. Vaccination in mice using monovalent vaccines elicited the highest neutralizing titers against each self-matched strain, but against other variants were reduced 2- to 73-fold. A bivalent vaccine consisting of WT and BA.5 broadened the neutralizing breadth against pre-Omicron and Omicron subvariants except XBB. Among bivalent vaccines based on the strains before the emergence of XBB, a bivalent vaccine consisting of BA.2 and BA.5 elicited the most potent neutralizing antibodies against Omicron subvariants, including XBB. In mice primed with injected WT vaccine, intranasal booster with a bivalent vaccine containing XBB and BA.5 could elicit broad serum and respiratory mucosal neutralizing antibodies against all late Omicron subvariants, including XBB. In mice that had been sequentially vaccinated with WT and BA.5, intranasal booster with a monovalent XBB vaccine elicited greater serum and mucosal XBB neutralizing antibodies than bivalent vaccines containing XBB. Both monovalent and bivalent XBB vaccines induced neutralizing antibodies against EG.5. Unlike the antibody response, which is highly variant-specific, mice receiving either monovalent or bivalent vaccines elicited comparable T-cell responses against all variants. Furthermore, intranasal but not intramuscular booster induced antigen-specific lung resident T cells. This study provides insights into the design of the COVID-19 vaccine and vaccination strategies.

Relative effectiveness of a heterologous booster dose with adenovirus type 5 vectored COVID-19 vaccine versus three doses of inactivated COVID-19 vaccine in adults during a nationwide outbreak of omicron predominance, in China: a retrospective, individually matched cohort-control study

Effectiveness of heterologous booster regimes with ad5 vectored COVID-19 vaccine in a large, diverse population during the national-scale outbreak of SARS-CoV-2 omicron predominance in China has not been reported, yet. We conducted a large-scale cohort-control study in six provinces in China, and did a retrospective survey on the COVID-19 attack risk during this outbreak. Participant aged ≥18 years in five previous trials who were primed with 1 to 3 doses of ICV received heterologous booster with either intramuscular or orally inhaled ad5 vectored COVID-19 vaccine were included in the heterologous-trial cohort. We performed propensity score-matching at a ratio of 1:4 to match participants in the heterologous-trial cohort individually with the community individuals who received three-dose of ICV as a control (ICV-community cohort). From February 4 to April 10, 2023, 41504 (74.5%) of 55710 individuals completed the survey. The median time since the most recent vaccination to the onset of the symptoms of COVID-19 was 303.0 days (IQR 293.0-322.0). The attack rate of COVID-19 in the heterologous-trial cohort was 55.8%, while that in the ICV-community cohort was 64.6%, resulting in a relative effectiveness of 13.7% (95% CI 11.9 to 15.3). In addition, a higher relative effectiveness against COVID-19 associated outpatient visits, and admission to hospital was demonstrated, which was 25.1% (95% CI 18.9 to 30.9), and 48.9% (95% CI 27.0 to 64.2), respectively. The heterologous booster with ad5 vectored COVID-19 vaccine still offered some additional protection in preventing COVID-19 breakthrough infection versus homologous three-dose regimen with ICV, 10 months after vaccination.

Dysfunctional host cellular immune responses are associated with mortality in melioidosis

Melioidosis is a tropical infection caused by the intracellular pathogen Burkholderia pseudomallei, an underreported and emerging global threat. As melioidosis-associated mortality is frequently high despite antibiotics, novel management strategies are critically needed. Therefore, we sought to determine whether functional changes in the host innate and adaptive immune responses are induced during acute melioidosis and are associated with outcome. Using a unique whole blood stimulation assay developed for use in resource-limited settings, we examined induced cellular functional and phenotypic changes in a cohort of patients with bacteremic melioidosis prospectively enrolled within 24 h of positive blood culture and followed for 28 days. Compared to healthy controls, melioidosis survivors generated an IL-17 response mediated by Th17 cells and terminally-differentiated effector memory CD8+ T cells (P < .05, both), persisting to 28 days after enrolment. Furthermore, melioidosis survivors developed polyfunctional cytokine production in CD8+ T cells (P < .01). Conversely, a reduction in CCR6+ CD4+ T cells was associated with higher mortality, even after adjustments for severity of illness (P = 0.004). Acute melioidosis was also associated with a profound acute impairment in monocyte function as stimulated cytokine responses were reduced in classical, intermediate and non-classical monocytes. Impaired monocyte cytokine function improved by 28-days after enrolment. These data suggest that IL-17 mediated cellular responses may be contributors to host defense during acute melioidosis, and that innate immune function may be impaired. These insights could provide novel targets for the development of therapies and vaccine targets in this frequently lethal disease.

Genomic diversity and evolutionary dynamics of Influenza A viruses in Colombian swine: implications for one health surveillance and control

Influenza A viruses (IAV) impose significant respiratory disease burdens in both swine and humans worldwide, with frequent human-to-swine transmission driving viral evolution in pigs and highlighting the risk at the animal-human interface. Therefore, a comprehensive One Health approach (interconnection among human, animal, and environmental health) is needed for IAV prevention, control, and response. Animal influenza genomic surveillance remains limited in many Latin American countries, including Colombia. To address this gap, we genetically characterized 170 swine specimens from Colombia (2011-2017). Whole genome sequencing revealed a predominance of pandemic-like H1N1 lineage, with a minority belonging to H3N2 and H1N2 human seasonal-like lineage and H1N1 early classical swine lineages. Significantly, we have identified reassortant and recombinant viruses (H3N2, H1N1) not previously reported in Colombia. This suggests a broad genotypic viral diversity, likely resulting from reassortment between classical endemic viruses and new introductions established in Colombia's swine population (e.g. the 2009 H1N1 pandemic). Our study highlights the importance of a One Health approach in disease control, particularly in an ecosystem where humans are a main source of IAV to swine populations, and emphasizes the need for continued surveillance and enhanced biosecurity measures. The co-circulation of multiple subtypes in regions with high swine density facilitates viral exchange, underscoring the importance of monitoring viral evolution to inform vaccine selection and public health policies locally and globally.

Prevalence and transmission of pretreatment drug resistance in people living with HIV-1 in Shanghai China, 2017-2021

The implementation of pretreatment drug-resistance (PDR) surveillance among people living with HIV-1 (PLWH) is a top priority in countries using efavirenz (EFV)/nevirapine (NVP) for first-line ART. In this study, we assessed the prevalence of PDR among PLWH in Shanghai, China during 2017-2021, and to reveal PDR transmission between Shanghai and other regions of China. A total of 5050 PLWH not on ART during 2017-2021 were included. Partial HIV-1 pol sequences were amplified, sequenced, and analysed for drug-resistance mutations (DRMs). Besides, transmission network of PDR variants was inferred using HIV-TRACE. The overall prevalence of PDR was 4.8% (242/5050; 95% CI, 4.2-5.4). Prevalence of NNRTI-associated PDR was 3.9% (95% CI, 3.4-4.5), higher than those of NRTI-associated (0.8%; 95% CI, 0.5-1.1) and PI-associated PDR (0.9%; 95% CI, 0.6-1.2). High prevalence of PDR (especially high-level resistance) to EFV (132/5050, 2.6%) and NVP (137/5050, 2.7%) were found. CRF01_AE (46.0%) was the predominant HIV-1 genotype with any DRMs, followed by CRF55_01B (21.0%), and CRF07_BC (15.1%). Two NRTI-associated (S68G/N/R and T215A/N/S/Y), five NNRTI-associated (V179D/E/T/L, K103N/R/S/T, E138A/G/K, V106M/I/A and Y181C/I) and two PI-associated mutations (M46I/L/V and Q58E) were the most common observed DRMs in PDR patients in Shanghai. The vast majority of S68G occurred in CRF01_AE (45%). M46I/L/V and Q58E showed a relatively high prevalence in CRF01_AE (4.1%) and CRF07_BC (12.6%). Transmission network analyses demonstrated cross-regional transmission links of PDR variants between Shanghai and other regions of China, which was mainly driven by the potential low-level DRM V179D/E. These results provide crucial information for clinical decision making of first-line ART in PLWH with PDR.

Intentions of healthcare seeking and self-isolation for MPOX among men who have sex with men in China: a national cross-sectional study

Linking identified MPOX cases to care is essential for MPOX control. This study aims to investigate the intentions of healthcare seeking and self-isolation for MPOX among men who have sex with men (MSM) in China. A cross-sectional online survey was conducted in early August 2023 in China. Respondents were recruited by community-based organizations (CBOs), collecting information on demographics, health status, behavioural and psychological characteristics. Univariate and multivariate logistic regression analyses were performed to examine the predictors of intentions to seek healthcare and self-isolate for MPOX within the MSM population. A total of 7725 participants were recruited, with a median age of 30 years. 92.21% of the participants would seek healthcare for MPOX-like symptoms, but only 52.50% intended to self-isolate if diagnosed. Intentions to seek healthcare were lower among those with MPOX-like symptoms in the past 3 months (standardized prevalence ratio (SPRs) = 0.82, 95% CI: 0.74-0.89) and the willingness to self-isolate was reduced among those diagnosed with MPOX in the past 3 months (SPRs = 0.65, 95% CI: 0.48-0.87). Participants free of sexually transmitted infections (STIs) and those aware of their HIV status were more likely to seek healthcare and self-isolate than those with STIs or unaware of their HIV status. Regular followers of MPOX information and those perceiving a low risk of infection were more inclined to take preventive measures. These findings highlight the need for targeted MPOX prevention strategies for high-risk groups and the importance of addressing barriers in infectious disease prevention response.

Human monoclonal antibody F61 nasal spray effectively protected high-risk populations from SARS-CoV-2 variants during the COVID-19 pandemic from late 2022 to early 2023 in China

Following the national dynamic zero-COVID strategy adjustment, the utilization of broad-spectrum nasal neutralizing antibodies may offer an alternative approach to controlling the outbreak of Omicron variants between late 2022 and early 2023 in China. This study involved an investigator-initiated trial (IIT) to assess the pharmacokinetic, safety and efficacy of the F61 nasal spray. A total of 2,008 participants were randomly assigned to receive F61 nasal spray (24 mg/0.8 mL/dose) or normal saline (0.8 mL/dose) and 1336 completed the follow-up in the IIT. Minimal absorption of F61 antibody into the bloodstream was detected in individuals receiving F61 nasal spray for seven consecutive days. No treatment-emergent adverse reactions of grade 3 severity or higher were reported. In the one-dose cohort, the 7-day cumulative SARS-CoV-2 infection rate was 79.0% in the F61 group and 82.6% in the placebo group, whereas, in the multiple-dose (once daily for 7 consecutive days) cohort, the rates were 6.55% in the F61 group and 23.83% in the placebo group. The laboratory-confirmed efficacy of F61 was 3.78% (-3.74%-10.75%) in the one-dose cohort and 72.19% (57.33%-81.87%) in the multiple-dose cohort. In the real-world study, 60,225 volunteers in four different regions were administered the F61 nasal spray based on the subject's wishes, over 90% efficacy rate was observed against different Omicron variants. The F61 nasal spray, with its favourable safety profile, could be a promising prophylactic monoclonal antibody against SARS-CoV-2 VOCs.

A systemic analysis of Creutzfeldt Jakob disease cases in Asia

Creutzfeldt Jakob Disease (CJD) is a rapidly progressive, fatal neurodegenerative disorder, also known as a subacute spongiform encephalopathy. There are three major subtypes of CJD i.e. Sporadic CJD, which occurs for reasons unbeknown to science (85% of known cases), Genetic or Familial CJD which is characterized by the presence of mutations in the human prion protein (PRNP) gene (10-15% cases) and Iatrogenic CJD that occurs via accidental transmission through medical and surgical procedures (1-2% cases). CJD cases occur globally with 1 case per one million population/year. Considerable data is available related to the incidence and prevalence of CJD in Europe and America. However, the global surveillance database is yet to include Asia even though several Asian countries have their own CJD monitoring units. sCJD is the highest among all CJD cases in Asia. China (1957) and Japan (1705) have reported more cases of sCJD than any Asian country and Hong Kong (1) has reported the least. On the other hand, gCJD is highest in Japan (370) and least in India (2). Our analysis establishes the presence of all variants of CJD across Asia. However, in most Asian countries in general and Southeast Asian countries in particular, CJD cases are misdiagnosed and often underreported. Since Asia is the most populated continent in the world, the actual global prevalence of CJD cannot be estimated until and unless these countries are accounted for. Concrete and reliable surveillance networks are needed across Asia to evaluate the prevalence and incidence of CJD in the region. [Figure: see text]The graphical abstract demonstrates the prevalence of CJD cases in the world and systematically analyses the incidence of CJD in Asian countries between the year 1986-2022. Highest number of cases were reported in Japan followed by China. The study emphasizes the need for assimilation of Asian data in global prevalence.

Genomic characters of Anaplasma bovis and genetic diversity in China

The emergence of Anaplasma bovis or A. bovis-like infection in humans from China and the United States of America has raised concern about the public health importance of this pathogen. Although A. bovis has been detected in a wide range of ticks and mammals in the world, no genome of the pathogen is available up to now, which has prohibited us from better understanding the genetic basis for its pathogenicity. Here we describe an A. bovis genome from metagenomic sequencing of an infected goat in China. Anaplasma bovis had the smallest genome of the genus Anaplasma, and relatively lower GC content. Phylogenetic analysis of single-copy orthologue sequence showed that A. bovis was closely related to A. platys and A. phagocytophilum, but relatively far from intraerythrocytic Anaplasma species. Anaplasma bovis had 116 unique orthogroups and lacked 51 orthogroups in comparison to other Anaplasma species. The virulence factors of A. bovis were significantly less than those of A. phagocytophilum, suggesting less pathogenicity of A. bovis. When tested by specific PCR assays, A. bovis was detected in 23 of 29 goats, with an infection rate up to 79.3% (95% CI: 64.6% ∼94.1%). The phylogenetic analyses based on partial 16S rRNA, gltA and groEL genes indicated that A. bovis had high genetic diversity. The findings of this study lay a foundation for further understanding of the biological characteristics and genetic diversity of A. bovis, and will facilitate the formulation of prevention and control strategies.

IS6 family insertion sequences promote optrA dissemination between plasmids varying in transfer abilities

Plasmids are the primary vectors for intercellular transfer of the oxazolidinone and phenicol cross-resistance gene optrA, while insertion sequences (ISs) are mobile genetic elements that can mobilize plasmid-borne optrA intracellularly. However, little is known about how the IS-mediated intracellular mobility facilitates the dissemination of the optrA gene between plasmid categories that vary in transfer abilities, including non-mobilizable, mobilizable, and conjugative plasmids. Here, we performed a holistic genomic study of 52 optrA-carrying plasmids obtained from searches guided by the Comprehensive Antibiotic Resistance Database. Among the 132 ISs identified within 10 kbp from the optrA gene in the plasmids, IS6 family genes were the most prevalent (86/132). Homologous gene arrays containing IS6 family genes were shared between different plasmids, especially between mobilizable and conjugative plasmids. All these indicated the central role of IS6 family genes in disseminating plasmid-borne optrA. Thirty-three of the 52 plasmids were harbored by Enterococcus faecalis found mainly in humans and animals. By Nanopore sequencing and inverse PCR, the potential of the enterococcal optrA to be transmitted from a mobilizable plasmid to a conjugative plasmid mediated by IS6 family genes was further confirmed in Enterococcus faecalis strains recovered from the effluents of anaerobic digestion systems for treating chicken manure. Our findings highlight the increased intercellular transfer abilities and dissemination risk of plasmid-borne optrA gene caused by IS-mediated intracellular mobility, and underscore the importance of routinely monitoring the dynamic genetic contexts of clinically important antibiotic resistance genes to effectively control this critical public health threat. KEY POINTS: • IS6 was prevalent in optrA-plasmids varying in intercellular transfer abilities. • Enterococcal optrA-plasmids were widespread among human, animal, and the environment. • IS6 elevated the dissemination risk of enterococcal optrA-plasmids.

Sufficient sleep and physical activity can relieve the effects of long-term exposure to particulate matter on depressive symptoms among 0.31 million children and adolescents from 103 counties in China

BACKGROUND

Although long-term exposures to air pollutants have been linked to mental disorders, existing studies remain limited and inconsistent. We investigated the relationship between exposure to particulate matter (PM) and depressive symptoms, as well as the potential role of sleep duration and physical activity.

METHOD

Using the surveillance data (2019 to 2022) of common diseases and risk factors among 312,390 students aged 10-25 years, logistic regression, generalized liner model (GLM) and restricted cubic spline (RCS) were employed to investigate the relationship between long-term exposure to PM and depressive symptoms.

RESULT

Significant associations were found between PM1 (OR = 1.21, 95 % CI: 1.12-1.32), PM2.5 (OR = 1.24, 95 % CI: 1.19-1.38), and PM10 (OR = 1.87, 95 % CI: 1.69-2.07) and increased risks of depressive symptoms. Sleep duration and physical activity relieved these associations. The odds ratios (ORs) of PM1, PM2.5, and PM10 on depressive symptoms were lower in group with sufficient sleep (1.02 vs. 1.49, 1.20 vs. 1.80, 2.15 vs. 2.23), lower in group with high level MVPA (1.13 vs. 1.48, 1.14 vs. 1.58, 1.85 vs. 2.38), and lower in group with high level outdoor activity (1.19 vs. 1.55, 1.23 vs. 1.63, 1.83 vs. 2.72).

LIMITATIONS

Conclusions about causality remain speculative because of the cross-sectional design.

CONCLUSION

Sufficient sleep duration and outdoor activity may mitigate the decline in mental health among adults in developing countries caused by long-term exposure to PM. This contribution enhanced our understanding of the mechanisms linking air pollution to mental health.

Rapid and extensive SARS-CoV-2 Omicron variant infection wave revealed by wastewater surveillance in Shenzhen following the lifting of a strict COVID-19 strategy

Wastewater-based epidemiology (WBE) has emerged as a promising tool for monitoring the spread of COVID-19, as SARS-CoV-2 can be shed in the faeces of infected individuals, even in the absence of symptoms. This study aimed to optimize a prediction model for estimating COVID-19 infection rates based on SARS-CoV-2 RNA concentrations in wastewater, and reveal the infection trends and variant diversification in Shenzhen, China following the lifting of a strict COVID-19 strategy. Faecal samples (n = 4337) from 1204 SARS-CoV-2 infected individuals hospitalized in a designated hospital were analysed to obtain Omicron variant-specific faecal shedding dynamics. Wastewater samples from 6 wastewater treatment plants (WWTPs) and 9 pump stations, covering 3.55 million people, were monitored for SARS-CoV-2 RNA concentrations and variant abundance. We found that the viral load in wastewater increased rapidly in December 2022 in the two districts, demonstrating a sharp peak in COVID-19 infections in late-December 2022, mainly caused by Omicron subvariants BA.5.2.48 and BF.7.14. The prediction model, based on the mass balance between total viral load in wastewater and individual faecal viral shedding, revealed a surge in the cumulative infection rate from <0.1 % to over 70 % within three weeks after the strict COVID-19 strategy was lifted. Additionally, 39 cryptic SARS-CoV-2 variants were identified in wastewater, in addition to those detected through clinical surveillance. These findings demonstrate the effectiveness of WBE in providing comprehensive and efficient assessments of COVID-19 infection rates and identifying cryptic variants, highlighting its potential for monitoring emerging pathogens with faecal shedding.

Immune responses and reinfection of SARS-CoV-2 Omicron variant in patients with lung cancer

A significant Omicron wave emerged in China in December 2022. To explore the duration of humoral and cellular response postinfection and the efficacy of hybrid immunity in preventing Omicron reinfection in patients with lung cancer, a total of 447 patients were included in the longitudinal study after the Omicron wave from March 2023 to August 2023. Humoral responses were measured at pre-Omicron wave, 3 months and 7 months postinfection. The detected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) specific antibodies including total antibodies, anti-receptor binding domain (RBD) specific IgG, and neutralizing antibodies against SARS-CoV-2 wild type (WT) and BA.4/5 variant. T cell responses against SARS-CoV-2 WT and Omicron variant were evaluated in 101 patients by ELISpot at 3 months postinfection. The results showed that Omicron-infected symptoms were mild, while fatigue (30.2%), shortness of breath (34.0%) and persistent cough (23.6%) were long-lasting, and vaccines showed efficacy against fever in lung cancer patients. Humoral responses were higher in full or booster vaccinated patients than those unvaccinated (p < .05 for all four antibodies), and the enhanced response persisted for at least 7 months. T cell response to Omicron was higher than WT peptides (21.3 vs. 16.0 SFUs/106 PBMCs, p = .0093). Moreover, 38 (9.74%) patients were reinfected, which had lower antibody responses than non-reinfected patients (all p < .05), and those patients of unvaccinated at late stage receiving anti-cancer immunotherapy alone were at high risk of reinfection. Collectively, these data demonstrate the Omicron infection induces a high and durable immune response in vaccinated patients with lung cancer, which protects vaccinated patients from reinfection.

Effects of socioeconomic status and regional inequality on the association between PM2.5 and its components and cardiometabolic multimorbidity: A multicenter population-based survey in eastern China

BACKGROUND

Despite evidence linking fine particulate matter (PM2.5) to cardiometabolic multimorbidity (CMM), the impact of its components remains unclear. Socioeconomic status (SES) and regional disparities may confound their association. We aim to evaluate the associations between PM2.5 components and CMM and explore how socioeconomic status and regional disparities affect these relationships.

METHODS

We recruited 108,941 participants aged 35-76 years from ten cities in eastern China. Individual exposure was assessed using Tracking Air Pollution in China (TAP) data, including PM2.5 and five components: ammonium (NH4+), black carbon (BC), nitrates (NO3-), organic matter (OM), and sulfates (SO42-). Generalized linear models and quantile g-computation models were employed to quantify the effects of PM2.5 components on CMM and to identify key components. Stratified analyses were performed to investigate the modifying effect of SES and regional disparities.

RESULTS

For each increase in interquartile range (IQR), BC (odds ratio [OR] 1.37, 95 % CI 1.29-1.47), OM (1.38, 1.29-1.48), NH4+ (1.31, 1.21-1.40), NO3- (1.34, 1.25-1.44), and SO42- (1.28, 1.20-1.38) were positively associated with CMM. Joint exposure to five components was significantly positively associated with CMM (OR: 1.27, 95 % CI: 1.21-1.33), with SO42- having the highest estimated weight, followed by NO3- and BC. These associations were stronger for participants from low socio-economic status and poor regions.

CONCLUSION

In summary, we found a stronger hazard effect of PM2.5 and its components on CMM, compared to those suffering from CMDs, particularly among participants with low socioeconomic status and in poor regions. SO42- may be a primary contributor to the association between PM2.5 components and CMM. These findings underscore the importance of prioritizing CMM and targeting SO42-related pollution sources in health policies, particularly amid China's aging population, reducing environmental health inequalities is critical.

Trends in cervical cancer: A decade‑long analysis of incidence, survival and demographic disparities in a Northern Italian province

While cervical cancer is relatively uncommon in Western countries, it continues to pose significant concern due to its high mortality rates. Intraepithelial forms [cervical intraepithelial neoplasia (CIN) 2 and CIN 3] are more prevalent in regions with comprehensive screening coverage, particularly in areas that use the Papanicolaou test and HPV detection. The present study aims to characterize the trends of precancerous lesions and infiltrating tumors over a decade, assessing survival rates by age, stage and country of origin. A total of 1,752 CIN 2/3 lesions and 152 infiltrating cancers were recorded in the Reggio Emilia Cancer Registry between January 2008 and December 2018. A clear increase in CIN 2/3 lesions was observed over the years while infiltrating tumors remained rare and the numbers of cancer cases declined. The 5-year survival rate was found to be 67%, with survival closely correlated with stage (88, 82, 74 and 12% for stages I, II, III and IV, respectively) and age (84, 80 and 37% for ages <40, 40-65 and 65+, respectively). Multivariable analysis confirmed an excess risk for advanced stages III (HR 3.1; 95% CI, 1.3-7.3) and IV (HR 19.6; 95% CI, 8.2-46.7), as well as in women 65+ (HR 2.8; 95% CI, 1.0-8.1). Analysis of national origins revealed comparable stage distribution for Italians and non-Italians at stage I (41 vs. 47%), while a notable disparity emerged for stage IV (28 vs. 6%). This difference could be attributed to the average age of Italians compared to non-Italians (59 vs. 49 years). Overall, the present study underscored the importance of continued surveillance and intervention strategies targeting advanced-stage disease, particularly in older populations and among non-Italian patients. Efforts to enhance screening coverage and access to timely interventions remain critical in reducing the burden of cervical cancer and improving survival outcomes.

The impact of social isolation on functional disability in older people: A multi-cohort study

OBJECTIVES

We assessed the relationship between social isolation and functional disability in older people.

DESIGN

Comparison of longitudinal cohort studies.

SETTING AND PARTICIPANTS

Harmonised longitudinal datasets from the United States, England, European countries, Japan, Korea, China and Hong Kong.

METHODS

Social isolation was operationalised as a composite score with five domains, such as marital status, living alone, and social contact with others. Functional disability was defined as whether the cohort participant had any difficulty in activities of daily living (ADL). In each dataset, we used robust Poisson regression models to obtain the relative risks (RRs) and the corresponding 95 % confidence intervals (CI). We combined the RRs to synthesize a pooled estimate using meta-analysis with random-effects models.

RESULTS

Overall, the social isolation composite score was not associated with ADL disability (pooled RR = 1.05, 95 % CI [0.97-1.14], n = 40,119). Subgroup analysis suggested social isolation composite score was associated with ADL disability in Asian regions (pooled RR = 1.09, 95 % CI [1.02, 1.16], but not in Western regions (pooled RR = 1.01, 95 % CI [0.96, 1.07]). The relationships between different domains of social isolation and ADL disability were heterogeneous, except that no participation in any social clubs or religious groups was consistently associated with ADL disability (pooled RR = 1.12, 95 % CI [1.04, 1.21]).

CONCLUSION

Targeting social isolation may prevent decline in functional abilities in older adults, providing an avenue to active and healthy ageing. Nonetheless, interventions tackling social isolation should tailor to the unique cultural and social underpinnings. A limitation of the study is that reverse causality could not be ruled out definitively.

Association analysis of antibiotic and disinfectant resistome in human and foodborne E. coli in Beijing, China

The widespread use of chemical disinfectants and antibiotics poses a major threat to food safety and human health. However, the mechanisms of co-transmission of antimicrobial resistance genes (ARGs) and biocides and metal resistance genes (BMRGs) of foodborne pathogens in the food chain is still unclear. This study isolated 343 E. coli strains from animal-derived foods in Beijing and incorporated online data of human-derived E. coli strains from NCBI. Our results demonstrated a relatively uniform distribution of strains from various regions in Beijing, indicating a lack of region-specific clustering. Additionally, predominant sequence types varied between food- and human-derived strains, suggesting a preference for different hosts and environments. Phenotypic association analysis showed that the chlorine disinfectants peroxides had a significant positive correlation with tetracyclines. Many more ARGs and BMRGs were enriched in human-associated E. coli compared with those in chicken- and pork-origin. The quaternary ammonium compounds (QACs) resistance gene qacEΔ1 had a strong correlation with aminoglycoside resistance gene aadA5, folate pathway antagonist resistance gene dfrA17, sul1 and macrolide resistance gene mph(A). The correlation results indicated a significant association between the copper resistance gene cluster pco and the silver resistance gene cluster sil. Coexistence of many resistance genes was observed within the qacEΔ1 gene structure, with qacEΔ1-sul1 being the most common combination. Our findings demonstrated that the epidemiological spread of resistance is affected by a combination of heavy metals, disinfectants and antibiotic use, suggesting that the prevention and control strategies of antimicrobial resistance need to be multifaceted and comprehensive.

Long-term PM2.5 exposure associated with severity of angina pectoris and related health status in patients admitted with acute coronary syndrome: Modification effect of genetic susceptibility and disease history

Long-term particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5) exposure has been associated with the occurrence of acute coronary syndrome (ACS). However, the impact of PM2.5 exposure and its components on the severity of angina pectoris and disease-related health status in patients hospitalized for ACS is understudied. To assess the association between long-term exposure to PM2.5 components and the angina pectoris severity in ACS patients, as well as the modification effects of genetic factors and disease history in north China. During 2017-2019, 6729 ACS patients were collected in Shandong Province and Beijing, with their angina pectoris severity evaluated using Seattle Angina Questionnaire (SAQ). The 0-3 years' average concentrations of PM2.5 and its five major components were assigned to each patient's residential address. Linear mixed-effects model, weighted quantile regression, and quantile g-computation were used to estimate the effects of both single and joint associations between PM2.5 components and SAQ scores. The interactive effect was estimated by polygenic risk scores and disease history. For each interquartile range increase in PM2.5, the overall SAQ score changed by -3.71% (95%CI: -4.54% to -2.88%), with score of angina stability more affected than angina frequency and other dimensions of angina pectoris severity. Sulfate and ammonium were major contributors to the effect of PM2.5 exposure. Significant modification effect was only observed for disease history, especially for the dimension of physical limitation. Among a series of pre-existing diseases, patients with a family history of coronary artery disease, previous percutaneous coronary intervention or coronary artery bypass grafting, and stroke were more susceptible to PM2.5 exposure than others. Greater exposure to PM2.5 is associated with more serious angina pectoris and worse disease-related health status in ACS patients. Public health and clinical priority should be given to cutting down key effective components and protecting highly vulnerable individuals.

Short-chain chlorinated paraffins may induce thymic aging in mice by activating PERK-CHOP

Humans indirectly consume approximately 0.02 mg/kg/day of short-chained chlorinated paraffins (SCCPs) through the environment; however, the thymic senescence/damage induced by SCCPs has not been assessed. In this study, 16 female mice (4-week-old) per group were orally administered 0, 0.01, 0.1, and 1 mg/kg/day of SCCPs for 21 days, and the phenotypes and levels of superoxide dismutase (SOD), malondialdehyde (MDA), Tβ4, αβ TCR, SA-β-Gal, GRP78, PERK/CHOP, P53/P21, and CASPASE-1 of the thymus were assessed as indicators. Another group comprising 16 mice was killed at 4-week-old and these indicators were assessed. Thereafter, the thymuses cultured in vitro were exposed to 0, 14, 140, and 1400 μg/L SCCPs, respectively, and the above indicators were measured after 7-day. Based on the results, the oral administration of ≥0.01 mg/kg/day SCCPs to mice and ≥14 μg/L of SCCPs in medium caused thymic aging features, such as a decrease in the ratio of cortex to medulla, gradual blurring of the boundary between the cortex and medulla, dose-dependent oxidative stress (decreased SOD and increased MDA), and decreased levels of Tβ4 and αβ TCRs in the thymus. The oral administration of ≥1 mg/kg/day of SCCPs also impeded the growth and development of female mice and their thymuses. Exposure to the low levels of SCCPs activated PERK-CHOP in the mouse thymus, which modulated increases in SA-β-Gal, IL-1β, P53, and CASPASE-1 in vivo and in vitro. Overall, environmental levels and human blood concentrations (14.8-1400 μg/L) of SCCPs may induce mouse thymus senescence by activating PERK-CHOP in vivo and in vitro, respectively.

Comparison of batch and continuous multi-column capture of monoclonal antibodies with convective diffusive membrane adsorbers

Protein A affinity membrane adsorbers are a promising alternative to resins to intensify the manufacturing of monoclonal antibodies. This study examined the process performance of convective diffusive membrane adsorbers operated in batch and continuous multi-column mode. Therefore, three different processes were compared regarding membrane utilization, productivity, and buffer consumption: the batch process, the rapid cycling parallel multi-column chromatography process, and the rapid cycling simulated moving bed process. The influence of the monoclonal antibody loading concentration (between 0.5 g L-1 and 5.2 g L-1) and the loading flow rate (between 1.25 MV min-1 and 10 MV min-1) on the monoclonal antibody binding behavior of the membrane adsorber were studied with breakthrough curve experiments. The determined breakthrough curves were used to calculate the monoclonal antibody dynamic binding capacity, the duration of the loading steps for each process, and the number of required membrane adsorbers for the continuous processes rapid cycling parallel multi-column chromatography and rapid cycling simulated moving bed. The highest productivity for the batch (176 g L-1 h-1) and rapid cycling parallel multi-column chromatography process (176 g L-1 h-1) was calculated for high monoclonal antibody loading concentrations and low loading flow rates. In contrast, the rapid cycling simulated moving bed process achieved the highest productivity (217 g L-1 h-1) for high monoclonal antibody loading concentrations and loading flow rates. Furthermore, due to the higher membrane utilization, the buffer consumption of the rapid cycling simulated moving bed process (1.1 L g-1) was up to 1.9 times lower than that of the batch or rapid cycling parallel multi-column chromatography operation (2.1 L g-1).

An entropy-based study on the mutational landscape of SARS-CoV-2 in USA: Comparing different variants and revealing co-mutational behavior of proteins

COVID-19 emergency has pushed the international scientific community to use every resource to combat the spread of the virus, to understand its biology and predict its possible evolution in terms of new variants. Since the first SARS-CoV-2 virus nucleotide and amino acid sequences were made available, information theory was used to study how viral information content was changing over time and then trace the evolution of its mutational landscape. In this work we analyzed SARS-CoV-2 sequences collected mainly in the USA in a period from March 2020 until December 2022 and computed mutation profiles of viral proteins over time through an entropy-based approach using Shannon Entropy and Hellinger distance. This representation allows an at-a-glance view of the mutational landscape of viral proteins over time and can provide new insights on the evolution of the virus from different points of view. Non-structural proteins typically showed flat mutation profiles, characterized by a very low Average mutation Entropy, while accessory and structural proteins showed mostly non uniform and high mutation profiles, often coupled with the predominance of variants. Interestingly NSP2 protein, whose function is currently still debated, falls in the same branch of NSP14 and NSP10 in the phylogenetic tree of mutations constructed through correlations of mutation profiles, suggesting a co-evolution of those proteins and a possible functional link with each other. To the best of our knowledge this is the first study based on a massive amount of data (n = 107,939,973) that analyzes from an entropy point of view the mutational landscape of SARS-CoV-2 over time and depicts a mutational temporal profile of each protein of the virus.

Spatiotemporal analysis of imported and local dengue virus and cases in a metropolis in Southwestern China, 2013-2022

Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013-2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August-October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing's appropriate dengue prevention and control strategies.

Association Between Community Elderly Care Services and the Physical and Emotional Burden of Family Caregivers of Older Adults: Evidence from Beijing, China

The rate of usage of community elderly care services in China is low, and past studies about the effects of these services on caregiver burden domestically are few. This study used a large sample of Beijing census data (n = 55,634) to examine the impact of these services on caregiver burden. Logistic regression and propensity score matching were used to estimate the effects. The results showed that meal assistance, respite care, and spiritual comfort are all significantly associated with a lower likelihood of perceived emotional burden among caregivers, while only respite care is very significantly associated with a lower likelihood of feeling physically burdened. However, the effects of these services on caregiver burden also depend on the activities of daily living performance and location of residence of the care recipients. The practical implications for policy makers are discussed.

Safety and efficacy of robotic anti-reflux surgery in geriatric patients: a comparative analysis

INTRODUCTION

As our population ages, older adults are being considered for anti-reflux surgery (ARS). Geriatric patients typically have heightened surgical risk, and literature has shown mixed results regarding postoperative outcomes. We sought to evaluate the safety and efficacy of robotic ARS in the geriatric population.

METHODS

We conducted a single-institution review of ARS procedures performed between 2009 and 2023. Patients ≥ 65 were assigned to the geriatric cohort. We compared operative details, lengths of stay (LOS), readmissions, reoperations, and complications between the two cohorts. The gastroesophageal reflux disease health-related quality of life (GERD-HRQL) survey and review of clinic notes were used to evaluate ARS efficacy.

RESULTS

628 patients were included, with 190 in the geriatric cohort. This cohort had a higher frequency of diabetes (16.3% vs 5.9% p < 0.0001), hypertension (50.0% vs 21.5% p < 0.0001), and heart disease (17.9% vs 2.3% p < 0.0001). Geriatric patients were more likely to exhibit hiatal hernias on imaging (51.6% vs 34.2% p < 0.0001) and were more likely to have large hernias (30.0% vs 7.1% p < 0.0001). Older adults were more likely to undergo Toupet fundoplications (58.4% vs 41.3%, p < 0.0001), Collis gastroplasties (9.5% vs 2.7% p < 0.0001), and relaxing incisions (11.6% vs 1.4% p < 0.0001). Operative time was longer for geriatric patients (132.0 min vs 104.5 min p < 0.0001). There were no significant differences in LOS, readmissions, or reoperations between cohorts. Geriatric patients exhibited lower rates of complications (7.4% vs. 14.6%, p = 0.011), but similar complication grades. Both groups had significant reduction in symptom scores from preoperative values. There were no significant differences in the reported symptoms between cohorts at any follow-up timepoint.

CONCLUSION

Geriatric robotic ARS patients tend to do as well as younger adults regarding postoperative and symptomatic outcomes, despite presenting with larger hiatal hernias and shorter esophagi. Clinicians should be aware of possible need for lengthening procedures or relaxing incisions in this population.

An SEIHR model with age group and social contact for analysis of Fuzhou COVID-19 large wave

Background

The structure of age groups and social contacts of the total population influenced infection scales and hospital-bed requirements, especially influenced severe infections and deaths during the global prevalence of COVID-19. Before the end of the year 2022, Chinese government implemented the national vaccination and had built the herd immunity cross the country, and announced Twenty Measures (November 11) and Ten New Measures (December 7) for further modifications of dynamic zero-COVID polity on the Chinese mainland. With the nation-wide vaccination and modified measures background, Fuzhou COVID-19 large wave (November 19, 2022-February 9, 2023) led by Omicron BA.5.2 variant was recorded and prevailed for three months in Fujian Province.

Methods

A multi-age groups susceptible-exposed-infected-hospitalized-recovered (SEIHR) COVID-19 model with social contacts was proposed in this study. The main object was to evaluate the impacts of age groups and social contacts of the total population. The idea of Least Squares method was governed to perform the data fittings of four age groups against the surveillance data from Fujian Provincial Center for Disease Control and Prevention (Fujian CDC). The next generation matrix method was used to compute basic reproduction number for the total population and for the specific age group. The tendencies of effective reproduction number of four age groups were plotted by using the Epiestim R package and the SEIHR model for in-depth discussions. The sensitivity analysis by using sensitivity index and partial rank correlation coefficients values (PRCC values) were operated to reveal the differences of age groups against the main parameters.

Results

The main epidemiological features such as basic reproduction number, effective reproduction number and sensitivity analysis were extensively discussed for multi-age groups SEIHR model in this study. Firstly, by using of the next generation matrix method, basic reproduction number R0 of the total population was estimated as 1.57 using parameter values of four age groups of Fuzhou COVID-19 large wave. Given age group k, the values of R0k (age group k to age group k), the values of R 0 k (an infected of age group k to the total population) and the values of R ^ 0 k (an infected of the total population to age group k) were also estimated, in which the explorations of the impacts of age groups revealed that the relationship R 0 k > R 0 k > R ^ 0 k was valid. Then, the fluctuating tendencies of effective reproduction number Rt were demonstrated by using two approaches (the surveillance data and the SEIHR model) for Fuzhou COVID-19 large wave, during which high-risk group (G4 group) mainly contributed the infection scale due to high susceptibility to infection and high risks to basic diseases. Further, the sensitivity analysis using two approaches (the sensitivity index and the PRCC values) revealed that susceptibility to infection of age groups played the vital roles, while the numerical simulation showed that infection scale varied with the changes of social contacts of age groups. The results of this study claimed that the high-risk group out of the total population was concerned by the local government with the highest susceptibility to infection against COVID-19.

Conclusions

This study verified that the partition structure of age groups of the total population, the susceptibility to infection of age groups, the social contacts among age groups were the important contributors of infection scale. The less social contacts and adequate hospital beds for high-risk group were profitable to control the spread of COVID-19. To avoid the emergence of medical runs against new variant in the future, the policymakers from local government were suggested to decline social contacts when hospital beds were limited.

COVID-19: from immune response to clinical intervention

The coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has highlighted the pivotal role of the immune response in determining the progression and severity of viral infections. In this paper, we review the most recent studies on the complicated dynamics between SARS-CoV-2 and the host immune system, highlight the importance of understanding these dynamics in developing effective treatments and formulate potent management strategies for COVID-19. We describe the activation of the host's innate immunity and the subsequent adaptive immune response following infection with SARS-CoV-2. In addition, the review emphasizes the immune evasion strategies of the SARS-CoV-2, including inhibition of interferon production and induction of cytokine storms, along with the resulting clinical outcomes. Finally, we assess the efficacy of current treatment strategies, including antiviral drugs, monoclonal antibodies, and anti-inflammatory treatments, and discuss their role in providing immunity and preventing severe disease.

What we learned from the infection control and what we need in the future: A quantitative and qualitative study on hospital infection prevention and control practitioners (HIPCPs) in Tianjin, China

BACKGROUND

In December 2022, the epidemic prevention and control policy was upgraded, and China entered a different stage of epidemic control. This study aims to identify implications for better infection control and health care supply during the epidemic.

METHODS

A longitudinal quantitative and qualitative study was performed based on 2 comprehensive questionnaire surveys among 497 hospital infection prevention and control practitioners (HIPCPs) before and during the epidemic peak in Tianjin, China.

RESULTS

The workload (8.2 hours vs 10.14 hours, P = 0) and self-reported mental health problems (23.5% vs 61.8%, P < .05) among the HIPCPs increased significantly in the peak period. Ward reconstruction and resource coordination were the most needed jobs in hospital infection control, and rapidly increased medical waste during the epidemic needs to be considered in advance. Community support for health care personnel and their families, maintaining full PPE to reduce simultaneous infection of medical staff, and clinical training of infectious diseases for medical staff, especially doctors, in advance are the most important things we learned.

CONCLUSION

Although it has been 4 years since the first outbreak of coronavirus disease 2019, more improvements should be made to prepare for the next epidemic of potential diseases.

The prevalence of hepatitis B virus infection among HIV-infected patients in the Ningxia Hui Autonomous Region, China, November 2002 to July 2023

We tested HIV-infected people with HBV serological markers of Ningxia. Of 1008 HIV-positive individuals, 70 (6.9 %) tested positive for HBsAg, 570 (56.5 %) tested positive for anti-HBs, and 483 (47.9 %) tested positive for anti-HBc. Of 70 HBV-positive individuals, 13 (18.5 %) tested positive for HBeAg, 31 (44.3 %) tested positive for anti-HBe, 3 (4.2 %) exhibited acute infection.

Burden and trends of mental disorders in China from 1990 to 2019: findings from the Global Burden of Disease Study 2019

PURPOSE

Mental disorders remain the leading causes of disability worldwide. We aimed to determine the burden and trends of mental disorders in China from 1990 to 2019.

METHODS

The incidence, prevalence, and disability-adjusted life years (DALYs) of mental disorders at national level of China were examined by age, sex, and subcategories. Temporal trends in the age-standardized rates for incidence, prevalence, and DALYs were assessed by the average annual percentage change (AAPC). All estimates are presented as numbers and age-standardized rates, with 95% uncertainty intervals (UIs).

RESULTS

The number of incident cases due to mental disorders increased from 42.90 million to 52.72 million, the number of prevalent cases increased from 132.63 million to 160.16 million, and the number of DALYs increased from 15.64 million to 20.29 million during 1990-2019. Decreasing trends were observed in the age-standardized rates for incidence, prevalence and DALYs. Anxiety and depressive disorders were more frequent in women, while ADHD, conduct disorder, and autism spectrum disorders were more common in men. Compared with 1990, the age-specific incidence rates were higher in individuals under 14 years and over 55 years, whereas rates were lower in those aged 15-49 years in 2019.

CONCLUSION

The number of incident cases, prevalent cases, and DALYs due to mental disorders gradually increased in China from 1990 to 2019. Anxiety and depressive disorders were the leading causes of burden due to mental disorders, which affected women more than men. Mental disorders deserve greater attention in health policy decision making.

Multi-omics and multi-stages integration identified a novel variant associated with silicosis risk

Assessing the association between candidate single-nucleotide polymorphisms (SNPs) identified by multi-omics approaches and susceptibility to silicosis. RNA-seq analysis was performed to screen the differentially expressed mRNAs in the fibrotic lung tissues of mice exposed to silica particles. Following this, we integrated the SNPs located in the above human homologenes with the silicosis-related genome-wide association study (GWAS) data to select the candidate SNPs. Then, expression quantitative trait locus (eQTL)-SNPs were identified by the GTEx database. Next, we validated the associations between the functional eQTL-SNPs and silicosis susceptibility by additional case-control study. And the contribution of the identified SNP and its host gene in the fibrosis process was further validated by functional experiments. A total of 12 eQTL-SNPs were identified in the screening stage. The results of the validation stage suggested that the variant T allele of rs419540 located in IL12RB1 significantly increased the risk of developing silicosis [additive model: odds ratio (OR) = 1.78, 95% confidence interval (CI) 1.11-2.85, P = 0.017]. Furthermore, the combination of GWAS and the results of validation stage also indicated that the variant T allele of rs419540 in IL12RB1 was associated with increased silicosis risk (additive model: OR = 2.07, 95% CI 1.38-3.12, P < 0.001). Additionally, after knockdown or overexpression of IL12RB1, the levels of pro-inflammatory factors, such as IL-12, IFN-γ, and other pro-inflammatory factors, were correspondingly decreased or increased. The novel eQTL-SNP, rs419540, might increase the risk of silicosis by modulating the expression levels of IL12RB1.

Sensory impairment, loneliness, and the discordance between subjective and objective cognitive function among older adults: A multi-cohort study

OBJECTIVES

This study aimed to examine the association between sensory impairment and the discordance between subjective/objective cognitive function among older adults and test the mediating effect of loneliness.

METHODS

We used data from four cohort studies conducted in 16 countries (N = 19,119). Sensory impairment and subjective cognitive impairment were self-reported. Objective cognitive impairment was measured in three dimensions. Generalized estimating equations were conducted to examine the association between sensory impairment and discordance in subjective/objective cognitive function. Cross-lagged panel model and a bootstrap method with 2,000 samples were employed to verify the mediating effect.

RESULTS

Sensory impairment was related to an increased risk of subjective cognitive impairment (OR = 4.70, 95 % CI 4.33-5.10), objective impairment (OR = 1.51, 95 %CI 1.31-1.74), as well as the discordance in subjective/objective cognitive function (OR = 1.35, 95 %CI 1.06-1.71 for older adults with normal subjective cognitive function). In contrast, sensory impairment was associated with a decreased risk of discordant subjective/objective cognitive function among those with subjective cognitive impairment (OR = 0.79, 95 %CI 0.66-0.94). Moreover, loneliness mediated the association between sensory impairment and subjective cognitive impairment (standardized indirect effect = 0.002, 95 %CI 0.001-0.004), objective cognitive impairment (standardized indirect effect = 0.005, 95 %CI 0.003-0.007) as well as the discordance in subjective/objective cognitive function (standardized indirect effect = 0.001, 95 %CI 0.001-0.003 for older adults with normal subjective cognitive function).

CONCLUSIONS

Significant association between sensory impairment and discordance in subjective/objective cognitive function and the mediating role of loneliness were revealed, varying by subjective cognitive function. Early screening on sensory impairment and targeted interventions on loneliness should be considered in future policies on cognitive impairment.

Epidemiological feature analysis of SVEIR model with control strategy and variant evolution

The complex interactions were performed among non-pharmaceutical interventions, vaccinations, and hosts for all epidemics in mainland China during the spread of COVID-19. Specially, the small-scale epidemic in the city described by SVEIR model was less found in the current studies. The SVEIR model with control was established to analyze the dynamical and epidemiological features of two epidemics in Jinzhou City led by Omicron variants before and after Twenty Measures. In this study, the total population (N) of Jinzhou City was divided into five compartments: the susceptible (S), the vaccinated (V), the exposed (E), the infected (I), and the recovered (R). By surveillance data and the SVEIR model, three methods (maximum likelihood method, exponential growth rate method, next generation matrix method) were governed to estimate basic reproduction number, and the results showed that an increasing tendency of basic reproduction number from Omicron BA.5.2 to Omicron BA.2.12.1. Meanwhile, the effective reproduction number for two epidemics were investigated by surveillance data, and the results showed that Jinzhou wave 1 reached the peak on November 1 and was controlled 7 days later, and that Jinzhou wave 2 reached the peak on November 28 and was controlled 5 days later. Moreover, the impacts of non-pharmaceutical interventions (awareness delay, peak delay, control intensity) were discussed extensively, the variations of infection scales for Omicron variant and EG.5 variant were also discussed. Furthermore, the investigations on peaks and infection scales for two epidemics in dynamic zero-COVID policy were operated by the SVEIR model with control. The investigations on public medical requirements of Jinzhou City and Liaoning Province were analyzed by using SVEIR model without control, which provided a possible perspective on variant evolution in the future.

Impact of mutations in SARS-CoV-2 recombinant sub-variant XBB.1.16 on the binding affinity with human ACE2 receptor

Despite the waning threat of the COVID-19 pandemic, its detrimental impact on global health persists. Regardless of natural immunity or immunity obtained through vaccination, emerging variants of the virus continue to undergo mutations and propagate globally. The persistent mutations in SARS-CoV-2, along with the subsequent formation of recombinant sub-variants has become a challenge for researchers and health professionals, raising concerns about the efficacy of current vaccines. Gaining a better understanding of the biochemical interactions between the Spike Protein (RBD) of SARS-CoV-2 variants and the human ACE2 receptor can prove to be beneficial in designing and developing antiviral therapeutics that are equally effective against all strains and emerging variants. Our objective in this study was to investigate the interfacial binding pattern of the SARS-CoV-2 RBD-ACE2 complex of the Wild Type (WT), Omicron, and the Omicron recombinant sub-variant XBB.1.16. We aimed to examine the atomic level factors and observe how mutations influence the interaction between the virus and its host using Molecular Dynamics simulation, MM/GBSA energy calculations, and Principal Component Analysis. Our findings reveal a higher degree of structural deviation and flexibility in XBB.1.16 compared to WT and Omicron. PCA indicated a wider cluster and significant flexibility in the movements of XBB.1.16 which can also be observed in free energy landscapes, while the normal mode analysis revealed converging motions within the RBD-ACE2 complexes which can facilitate the interaction between them. A pattern of decreased binding affinity was observed in case of XBB.1.16 when compared to the WT and Omicron. These observed deviations in XBB.1.16 when compared to its parent lineage Omicron, and WT can be attributed to the mutations specific to it. Collectively, these results enhance our understanding of the impact of mutations on the interaction between this strain and the host, taking us one step closer to designing effective antiviral therapeutics against the continually mutating strains.

Epidemics and diversity of norovirus variants with acute gastroenteritis outbreak in Hongshan District, Wuhan City, China, 2021-2023

BACKGROUND

Norovirus is the predominant pathogen causing foodborne illnesses and acute gastroenteritis (AGE) outbreaks worldwide, imposing a significant disease burden. This study aimed to investigate the epidemiological characteristics and genotypic diversity of norovirus outbreaks in Hongshan District, Wuhan City.

METHODS

A total of 463 AGE cases from 39 AGE-related outbreaks in Hongshan District between January 1, 2021, and June 30, 2023, were included in the study. Reverse transcription-polymerase chain reaction (RT-PCR) was used to identify norovirus types GI and GII in anal swab samples from all cases. Norovirus-positive samples were sequenced and analyzed for the open reading frame (ORF) 1/ORF2 hinge region.

RESULTS

26 norovirus infectious outbreaks were reported among 39 acute diarrheal outbreaks, including 14 outbreaks in kindergartens, 8 in elementary schools, and 4 in universities. Based on clinical symptoms and epidemiological investigations, a total of 1295 individuals were identified as having been exposed to norovirus, yielding an attack rate of 35.75 %. A higher proportion of outbreaks was observed during the winter and spring seasons (38.46 %). Additionally, norovirus-positive samples were subjected to sequencing and analysis of the open reading frame (ORF) 1/ORF2 hinge region. Genotypic data for norovirus was successfully obtained from 18 (69.23 %) of the infectious outbreaks, revealing 10 distinct recombinant genotypes. GII.4 Sydney 2012 [P31] and GII.17[P17] were the predominant strains in 2021 and 2022, GII.3 [P12] emerged as the dominant strain in 2023.

CONCLUSION

Norovirus outbreaks in Hongshan District predominantly occurred in crowded educational institutions, with peaks in the cold season and a high attack rate in universities. GII.3 [P12] has become the locally predominant strain.

Whole-genome analysis of circulating influenza A virus (H3N2) strains in Shanghai, China from 2005 to 2023

Seasonal influenza A virus subtype H3N2 (A/H3N2) circulates globally and has been linked to higher hospitalization rates and summer outbreaks in temperate regions. Here, A/H3N2 circulation in Shanghai, China was systematically studied using data and materials generated by the Shanghai influenza surveillance network from 2005 to 2023. Time-series analysis of incidence and subtyping data showed that A/H3N2 co-circulated with other (sub)types and dominated in multiple seasonal influenza peaks, preferentially in summer. Whole genomes of 528 representative strains were sequenced, and spatiotemporal phylodynamic analysis using these and GISAID-archived sequences demonstrated that in the years before the COVID-19 pandemic, phylogenetically similar strains were circulating locally and elsewhere. However, clade 1a.1 (within 3C.2a.1b.2a), circulated in and only in Shanghai and domestically in 2022, while the sibling clade 2 predominated in other regions. Interestingly, clade 1a.1 was swiftly and completely replaced by clade 2, mostly 2a.3a.1, at the start of 2023. In hemagglutination inhibition and neutralization assays, sera from healthy donors collected in 2022 displayed higher or similar reactivity against 2a.3a.1 compared to 1a.1. By contrast, transcription and replication competence of 2a.3a.1 in MDCK cells was higher than 1a.1. These results indicated that instead of antigenicity differences enabling evasion of pre-existing immunity, higher replicative capability more likely contributed to 2a.3a.1 viruses achieving dominance in China. In addition to summarizing patterns of A/H3N2 local circulation in Shanghai, this work revealed an unusual episode in A/H3N2 global circulation and evolution dynamics in connection to the COVID-19 pandemic and explored possible mechanistic explanations.