[Epidemic trends and prevention and control of seasonal influenza in China after the COVID-19 pandemic]

During the COVID-19 pandemic, a series of non-pharmaceutical interventions, which were implemented to curb the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), significantly modified the seasonal pattern of influenza. The intensity of influenza activity markedly decreased and B/Yamagata lineage was no longer detected. As the national influenza sentinel surveillance data shown, clear seasonal patterns were observed for influenza between 2012-2019, annually with an average of 14.57% of specimens tested positive for influenza virus. However, the seasonal pattern of influenza was disrupted after the outbreak of COVID-19. In the 2020-2021 season, influenza demonstrated an extremely low activity (yearly positivity rate<1.0%), followed by a resurgence of winter peak in the 2021-2022 season. Following the downgrade of management of COVID-19 to Class B in China in December 26, 2022, social activities gradually resumed, leading to the rebound of influenza activity with an out-of-season ciculation. After COVID-19 pademic, other respiratory infectious diseases caused by SARS-CoV-2, respiratory syncytial virus, and mycoplasma pneumonia were alternatively or concurrently circulated with influenza. The prevention and control of influenza and other respiratory infectious diseases emphasizes a multi-disease prevention strategy, including long-term and continuous monitoring the epidemic trends in influenza virus and SARS-CoV-2, promoting influenza and COVID-19 vaccination among key populations, and strengthening the knowledge and public awareness of prevention and control for respiratory infectious diseases, etc.

Amorphous Chloride Solid Electrolytes with High Li-Ion Conductivity for Stable Cycling of All-Solid-State High-Nickel Cathodes

Solid electrolytes (SEs) are central components that enable high-performance, all-solid-state lithium batteries (ASSLBs). Amorphous SEs hold great potential for ASSLBs because their grain-boundary-free characteristics facilitate intact solid-solid contact and uniform Li-ion conduction for high-performance cathodes. However, amorphous oxide SEs with limited ionic conductivities and glassy sulfide SEs with narrow electrochemical windows cannot sustain high-nickel cathodes. Herein, we report a class of amorphous Li-Ta-Cl-based chloride SEs possessing high Li-ion conductivity (up to 7.16 mS cm-1) and low Young's modulus (approximately 3 GPa) to enable excellent Li-ion conduction and intact physical contact among rigid components in ASSLBs. We reveal that the amorphous Li-Ta-Cl matrix is composed of LiCl43-, LiCl54-, LiCl65- polyhedra, and TaCl6- octahedra via machine-learning simulation, solid-state 7Li nuclear magnetic resonance, and X-ray absorption analysis. Attractively, our amorphous chloride SEs exhibit excellent compatibility with high-nickel cathodes. We demonstrate that ASSLBs comprising amorphous chloride SEs and high-nickel single-crystal cathodes (LiNi0.88Co0.07Mn0.05O2) exhibit ∼99% capacity retention after 800 cycles at ∼3 C under 1 mA h cm-2 and ∼80% capacity retention after 75 cycles at 0.2 C under a high areal capacity of 5 mA h cm-2. Most importantly, a stable operation of up to 9800 cycles with a capacity retention of ∼77% at a high rate of 3.4 C can be achieved in a freezing environment of -10 °C. Our amorphous chloride SEs will pave the way to realize high-performance high-nickel cathodes for high-energy-density ASSLBs.

[Establishing adult vaccination system to improve the quality of immunization services over the life course]

The scientific setting and standardized management of adult vaccination clinics will improve the accessibility of vaccination services, thereby increasing the vaccination rate. Currently, some provinces and cities in China have been exploring the construction of adult vaccination systems for many years, effectively improving the level of vaccination services, and forming some useful experiences and models. However, the construction of China's adult vaccination system is not yet perfect, and the service mode needs to be optimized. In the future, we should continue to improve the guarantee measures for adult vaccination, scientifically lay out the network, optimize the service mode, and improve the overall quality of immunization services over the life course.

[Research and reflection on the diversified method system of multi-stages and multi-scenarios surveillance and early warning of infectious diseases]

With the outbreak of infectious diseases, more and more attention has been paid to surveillance and early warning work. Timely and accurate monitoring data is the basis of infectious diseases prevention and control. Effective early warning methods for infectious diseases can improve the timeliness and sensitivity of early warning work. This paper briefly introduces the intelligent early warning model of infectious diseases, summarizes the emerging surveillance and early warning methods of infectious diseases, and seeks the possibility of diversified surveillance and early warning in different epidemic stages and different outbreak scenarios of infectious diseases. This paper puts forward the idea of constructing a diversified method system of infectious diseases surveillance and early warning based on multi-stages and multi-scenarios and discusses the future development trend of infectious diseases surveillance and early warning, in order to provide reference for improving the construction level of infectious diseases surveillance and early warning system in China.

[Progress and challenge in intelligent syndromic surveillance for infectious diseases]

Intelligent syndromic surveillance is an important part of multi-point triggering and multi-channel surveillance system of intelligent early warning of infectious diseases in China, and an inevitable development process of traditional syndromic surveillance as the constant emergence of new technologies. Intelligent syndromic surveillance collects not only the medical data of patients seeking medical care in hospitals but also massive non-medical information. However, along with its rapid development, challenges in intelligent syndromic surveillance have emerged, such as information explosion, cost-effective balance, information sharing, data security and privacy. This paper summarizes the concept and development of intelligent syndromic surveillance to provide references for the method and technique development of intelligent early warning of infectious diseases and new thought for the prevention and control of infectious diseases in China and in the world.

Pseudohalogen Resurfaced CsPbBr3 Nanocrystals for Bright, Efficient, and Stable Green-Light-Emitting Diodes

Lead halide perovskite nanocrystals (LHP NCs) are regarded as promising emitters for next-generation ultrahigh-definition displays due to their high color purity and wide color gamut. Recently, the external quantum efficiency (EQE) of LHP NC based light-emitting diodes (PNC LEDs) has been rapidly improved to a level required by practical applications. However, the poor operational stability of the device, caused by halide ion migration at the grain boundary of LHP NC thin films, remains a great challenge. Herein, we report a resurfacing strategy via pseudohalogen ions to mitigate detrimental halide ion migration, aiming to stabilize PNC LEDs. We employ a thiocyanate solution processed post-treatment method to efficiently resurface CsPbBr₃ NCs and demonstrate that the thiocyanate ions can effectively inhibit bromide ion migration in LHP NC thin films. Owing to thiocyanate resurfacing, we fabricated LEDs with a high EQE of 17.3%, a maximum brightness of 48000 cd m^-2, and an excellent operation half-life time.

[Thinking about development of multi-channel surveillance and multi-dimensional early warning system of emerging respiratory communicable diseases]

The world has paid a heavy price for the pandemic of the emerging respiratory communicable disease, so more concern about communicable disease surveillance and early warning has been aroused. This paper briefly reviews the establishment of the surveillance and early warning system of respiratory communicable diseases in China, discusses its future development and introduces the novel surveillance methods and early warning models for the purpose of establishment of a multi-channel surveillance and multi-dimensional early warning system of communicable diseases in the future and the improvement of the prevention and control of emerging respiratory communicable diseases in China.

[Research progress on the effectiveness of smallpox vaccination against mpox virus infection]

With the expansion of mpox virus infection from endemic to a global epidemic in 2022, the WHO declared that the mpox event constituted a Public Health Emergency of International Concern. Due to the high degree of gene sequence similarity among orthopox viruses and cross-reactive antibodies induced by orthoviruses, smallpox vaccination may affect the immune response induced by mpox virus infection. The analysis of the protective effects of smallpox vaccination against mpox virus infection will help define the focus of prevention and control. In this review, we clarify the protection of the smallpox vaccine against mpox virus infection by analyzing the correlation between smallpox vaccination, immune response status, and clinical data and providing evidence for the prevention, control, and strategies of mpox epidemics.

A LaCl3-based lithium superionic conductor compatible with lithium metal

Inorganic superionic conductors possess high ionic conductivity and excellent thermal stability but their poor interfacial compatibility with lithium metal electrodes precludes application in all-solid-state lithium metal batteries1,2. Here we report a LaCl3-based lithium superionic conductor possessing excellent interfacial compatibility with lithium metal electrodes. In contrast to a Li3MCl6 (M = Y, In, Sc and Ho) electrolyte lattice3-6, the UCl3-type LaCl3 lattice has large, one-dimensional channels for rapid Li+ conduction, interconnected by La vacancies via Ta doping and resulting in a three-dimensional Li+ migration network. The optimized Li0.388Ta0.238La0.475Cl3 electrolyte exhibits Li+ conductivity of 3.02 mS cm-1 at 30 °C and a low activation energy of 0.197 eV. It also generates a gradient interfacial passivation layer to stabilize the Li metal electrode for long-term cycling of a Li-Li symmetric cell (1 mAh cm-2) for more than 5,000 h. When directly coupled with an uncoated LiNi0.5Co0.2Mn0.3O2 cathode and bare Li metal anode, the Li0.388Ta0.238La0.475Cl3 electrolyte enables a solid battery to run for more than 100 cycles with a cutoff voltage of 4.35 V and areal capacity of more than 1 mAh cm-2. We also demonstrate rapid Li+ conduction in lanthanide metal chlorides (LnCl3; Ln = La, Ce, Nd, Sm and Gd), suggesting that the LnCl3 solid electrolyte system could provide further developments in conductivity and utility.

[The value of vaccines from the perspective of population medicine]

Vaccination is one of the most effective, broad-reach, and cost-effective public health initiatives to fight against infectious diseases. From the perspective of population medicine, this article systematically elaborates on the value of vaccines in preventing infections, reducing disease incidence, decreasing disability and severe cases, lowering mortality rates, improving population health and life expectancy, reducing antibiotic use and resistance, as well as promoting fairness in public health services. Based on the current situation, the following recommendations are proposed: first, strengthen scientific research to provide a solid foundation for related policy-making; second, increase the coverage rate of non-national immunization program vaccines; third, promote the inclusion of more appropriate vaccines in the national immunization program; fourth, strengthen the research and development of new vaccines; and fifth, increase talent training in the field of vaccinology.

[Consideration on the usage of full-dose influenza vaccine for the infants aged 6-35 months old]

Seasonal influenza has a high disease burden, and children infected with influenza are prone to multiple complications. Influenza vaccination is effective in preventing infection and reducing risks of severe diseases and complications. Influenza vaccines are trivalent and quadrivalent, depending on the components of the vaccine. According to the hemagglutinin content, it can be divided into full dose and half dose of influenza vaccine for children. The findings from clinical trials and real-world studies suggested, the full-dose influenza vaccine as in adults has the same safety profile and higher immunogenicity in children aged 6 to 35 months. The application of full-dose influenza vaccine in children aged 6 to 35 months can greatly improve the flexibility and convenience of vaccination, and help reduce the workload in the process.

[Clinical research progress of human respiratory syncytial virus vaccine]

Human respiratory syncytial virus (HRSV) is one of the main pathogen causing severe acute lower respiratory tract infections in infants and the elderly, with high incidence rate and mortality worldwide. Vaccine is one of the important measure to prevent infection, transmission and severe disease of HRSV, but currently there is no officially approved preventive vaccine for prevention of HRSV in the world. This paper reviews and analyzes the current research and development progress of HRSV vaccine, summarizes the design routes of different types of HRSV preventive vaccines, and discusses the difficulties and challenges in vaccine research and development, in order to provide reference for the research and development of HRSV vaccine and the development of clinical trials.

[Research progress on the burden of respiratory syncytial virus infection in the elderly]

Human Respiratory Syncytial Virus (HRSV) is a serious threat to the population health. The elderly are one of the susceptible populations. The prevalence of HRSV in the elderly is generally higher than that in other age groups except children, which has gradually attracted attention in recent years. This paper reviewed the prevalence, common complications and major complications of HRSV in the elderly, briefly expounded the economic burden of HRSV infection, and proposed that attention should be paid to the disease burden of the elderly after HRSV infection, timely treat common complications, so as to reduce the occurrence of adverse survival outcomes and provide scientific evidence for the prevention and control of HRSV infection in the elderly.

Planar defect-free pure red perovskite light-emitting diodes via metastable phase crystallization

Solution-processable all-inorganic CsPbI_3-xBr_x perovskite holds great potential for pure red light-emitting diodes. However, the widely existing defects in this mixed halide perovskite markedly limit the efficiency and stability of present light-emitting diode devices. We here identify that intragrain Ruddlesden-Popper planar defects are primary forms of such defects in the CsPbI_3-xBr_x thin film owing to the lattice strain caused by inhomogeneous halogen ion distribution. To eliminate these defects, we develop a stepwise metastable phase crystallization strategy to minimize the CsPbI_3-xBr_x perovskite lattice strain, which brings planar defect-free CsPbI_3-xBr_x thin film with improved radiative recombination, narrowed emission band, and enhanced spectral stability. Using these high-quality thin films, we fabricate spectrally stable pure red perovskite light-emitting diodes, showing 17.8% external quantum efficiency and 9000 candela meter^-2 brightness with color coordinates required by Rec. 2020.

[Research progress on early warning model of influenza]

Influenza is an acute respiratory infectious disease caused by influenza virus. It usually exhibits seasonal transmission, but the novel influenza strain can lead to a pandemic with severe human health and socioeconomic consequences. Early warning of influenza epidemic is an important strategy and means for influenza prevention and control. On the basis of reviewing the main influenza surveillance and early warning systems, this study summarizes the principles, applications, advantages and disadvantages, and development prospects of common influenza early warning models, in order to provide reference for research and application of early warning technology for influenza and other acute respiratory infectious diseases.

[Research on the interaction between COVID-19 and influenza]

Since the global pandemic of COVID-19, different countries have implemented various prevention and control measures, which has affected the epidemic characteristics of respiratory infectious diseases such as influenza. From 2020 to 2021, the level of influenza activity was relatively low, but it is necessary to be alert that with the adjustment of national prevention and control measures, influenza may have a relatively strong epidemic rebound. In order to deal with influenza epidemic, experts were organized to publish a series of influenza studies in this issue, suggesting that influenza prevention and control cannot be underestimated during the COVID-19 pandemic. It is suggested to carry out research on the interaction between COVID-19 and influenza to explore the epidemic characteristics of the disease, develop new technologies and tools to improve the efficiency of monitoring and early warning, identify obstacles to vaccination, promote the scientific implementation of intervention measures, and achieve joint prevention and control of multiple diseases.

[Thoughts and suggestions on co-administration of seasonal influenza vaccine and COVID-19 vaccine]

In the context of the global pandemic of COVID-19, the epidemic intensity, epidemic characteristics and infection risk of influenza have presented new features. COVID-19 and influenza have simultaneously emerged in many regions of the world. COVID-19 and influenza are similar in terms of transmission mode, clinical symptoms and other aspects. There are also similarities in the mechanism of influenza virus and novel coronavirus on cells. At the same time, it is feasible and significant to do a good job in the prevention and control of COVID-19 and influenza. This paper discusses the relevant strategies and measures for the joint prevention and control of influenza and novel coronavirus from the aspects of influenza vaccination to prevent co-infection, simultaneous vaccination of influenza vaccine and novel coronavirus vaccine, etc., and puts forward corresponding thoughts and suggestions, in order to provide scientific support for the formulation of strategies on seasonal influenza vaccine and novel coronavirus vaccination.

[Understanding the behavioural and social drivers of vaccine uptake: introduction and implications of World Health Organization Position Paper, 2022]

On May 20, 2022, World Health Organization (WHO) Position Paper on Understanding the Behavioural and Social Drivers of Vaccine Uptake (BeSD) was published. This review introduced the BeSD toolkit, interventions to increase vaccine uptake, and offered WHO's position and recommendation. Based on immunization practice, this position paper had some implications for improving the vaccination coverage in China: (1) To promote the BeSD toolkit localization; (2) To integrate the measurement and monitoring of BeSD into multisectoral routine efforts; (3) To enhance the diversity and professionalization of immunization practitioners; (4) To design and carry out implementation research scientifically.

[Introduction and implications of WHO position paper: vaccines against influenza, May 2022]

On May 13, 2022, World Health Organization(WHO) Position Paper on Influenza Vaccine (2022 edition) was published. This position paper updates information on influenza epidemiology, high risk population, the impact of immunization on disease, influenza vaccines and effectiveness and safety, and propose WHO's position and recommendation that all countries should consider implementing seasonal influenza vaccine immunization programmes to prepare for an influenza pandemic. In addition, it proposes that the influenza surveillance platform can be integrated with the surveillance of other respiratory viruses, such as SARS-CoV-2 and Respiratory Syncytial Virus. This position paper has some implications for the prevention and control of influenza and other respiratory infectious diseases in China: (1) Optimize influenza vaccine policies to facilitate the implementation of immunization services; (2) Influenza prevention and control should from the perspective of Population Medicine focus on the individual and community to integrate with "Promotion, Prevention, Diagnosis, Control, Treatment, Rehabilitation"; (3) Incorporate prevention and control of other respiratory infectious diseases such as influenza, COVID-19, respiratory syncytial virus and adenovirus, and intelligently monitor by integrating multi-channel data to achieve the goal of co-prevention and control of multiple diseases.

[Strengthen evaluation of vaccine effectiveness to facilitate scientific and targeted prevention and control of the COVID-19 pandemic]

The COVID-19 continues to spread throughout the world, and local clusters and outbreaks related to overseas imports have occurred in many places in China. Vaccination against COVID-19 is one of the most effective tools to prevent disease, severe illness and death. For vaccines developed and used by China, it is particularly important for scientific and targeted prevention and control to study different outbreak scenarios, to conduct in-depth real-world research on SARS-CoV-2 variants, and to further promote vaccine development and technical reserves. This article commented the effectiveness of COVID-19 vaccine, and prospected the future research on vaccine efficacy, immunization strategy and vaccine development, which provided evidence for optimizing vaccination strategy.

α-BaF2 Nanoparticle Substrate-Enabled γ-CsPbI3 Heteroepitaxial Growth for Efficient and Bright Deep-Red Light-Emitting Diodes

All-inorganic CsPbI₃ perovskite is attractive for deep-red light-emitting diodes (LEDs) because of its excellent carrier mobility, high color purity, and solution processability. However, the high phase transition energy barrier of optically active CsPbI₃ black phase hinders the fabrication of efficient and bright LEDs. Here, we report a novel α-BaF₂ nanoparticle substrate-promoted solution-processable heteroepitaxial growth to overcome this hindrance and obtain high-quality optically active γ-CsPbI₃ thin films, achieving efficient and bright deep-red LEDs. We unravel that the highly exposed planes on the α-BaF₂ nanoparticle-based heteroepitaxial growth substrate have a 99.5% lattice matching degree with the (110) planes of γ-CsPbI₃. This ultrahigh lattice matching degree initiates solution-processed interfacial strain-free epitaxial growth of low-defect and highly oriented γ-CsPbI₃ thin films on the substrate. The obtained γ-CsPbI₃ thin films are uniform, smooth, and highly luminescent, based on which we fabricate efficient and bright deep-red LEDs with a high peak external quantum efficiency of 14.1% and a record luminance of 1325 cd m^-2.

[Progress in research of safety, efficiency and vaccination status of influenza vaccine in populations at high risk]

This paper reviews the domestic and foreign studies published in 2020 on the application of influenza vaccine in populations at high risk. The importance of influenza vaccination in population at high risk has been proved by larger sample, multicentre, high-quality evidence-based studies. Influenza vaccination is the most cost-effective measure to prevent influenza. However, the coverage rate of influenza vaccine is very low in China, it is necessary to strengthen the health education to promote influenza vaccination in different populations. It is recommended to give influenza vaccination to the population in whom influenza vaccination has been proven safe and effective before influenza season. Research of the safety, efficiency and cost-effectiveness of influenza vaccine should be accelerated for the populations in whom such data are lacking or insufficient.

[Consideration on implementation of co-administration of Seasonal Influenza and COVID-19 vaccines during pandemic in China]

Influenza is an infectious respiratory disease caused by the influenza viruses. Older people, infants and people with underlying medical conditions could have a higher risk of severe influenza symptoms and complications. The co-infection of Coronavirus Diseases 2019 (COVID-19) with influenza viruses could lead to the complication of prevention, diagnosis, control, treatment, and recovery of COVID-19. Influenza vaccine and COVID-19 vaccine overlapped in target populations, vaccination time, and inoculation units. Although there was insufficient evidence on the immunogenicity and safety of co-administration of influenza vaccine and COVID-19 vaccine, World Health Organization and some countries recommended co-administration of inactivated influenza vaccine and COVID-19 vaccine. This review summarized domestic and international vaccination policies and research progress, and put forward corresponding suggestions in order to provide scientific support for the formulation of vaccination strategy on seasonal influenza vaccine and COVID-19 vaccine.

[A randomized controlled trial study of immunogenicity and safety of an inactivated SARS-CoV-2 vaccine in different immunization schedules]

Objective: To compare the immunogenicity and safety of an inactivated SARS-CoV-2 vaccine used for the vaccination in public security officers with different immunization schedules. Methods: From January to February, 2021, 405 public security officers in Taiyuan were randomly divided into 3 groups. Two doses of SARS-CoV-2 inactivated vaccine were injected according to the immunization schedule of 0-14 days, 0-21 days or 0-28 days, respectively. The nucleic acid of SARS-CoV-2 was detected by reverse transcription polymerase chain reaction. The neutralizing antibodies to SARS-CoV-2 were tested by microdose cytopathogenic efficiency assay of live virus. The GMT, seroconversion rate of SARS-CoV-2 neutralizing antibody and safety of the vaccine were analyzed for the 3 groups. Results: The seroconversion rate of SARS-CoV-2 neutralizing antibody was 100% in all the 3 groups. The SARS-CoV-2 neutralizing antibody level of 0-21 day group [166.70 (95%CI: 148.30-185.10)] was similar to that of 0-28 day group [179.50 (95%CI: 156.50-202.60)] (P>0.05), significantly higher than that of 0-14 day group [86.08 (95%CI: 72.36-99.80)] (P<0.001). The incidence rates of adverse reaction in the 3 groups were 1.48% (2/135), 0.74% (1/136) and 1.49% (2/134) respectively (P=0.750), all the adverse reactions were mild. Conclusions: The vaccination of inactivated SARS-CoV-2 vaccine with different immunization schedules in public security officers showed good safety and high seroconversion rate, and the GMTs of SARS-CoV-2 neutralizing antibody in 0-21 day group and 0-28 day group were higher than that in 0-14 day group.

Spectrally Stable and Efficient Pure Red CsPbI3 Quantum Dot Light-Emitting Diodes Enabled by Sequential Ligand Post-Treatment Strategy

Metal halide perovskites are promising semiconductors for next-generation light-emitting diodes (LEDs) due to their high luminance, excellent color purity, and handily tunable band gap. However, it remains a great challenge to develop perovskite LEDs (PeLEDs) with pure red emission at the wavelength of 630 nm. Herein, we report a spectrally stable and efficient pure red PeLED by employing sequential ligand post-treated CsPbI₃ quantum dots (QDs). The synthesized CsPbI₃ QDs with a size of ∼5 nm are treated in sequential steps using the ligands of 1-hydroxy-3-phenylpropan-2-aminium iodide (HPAI) and tributylsulfonium iodide (TBSI), respectively. The CsPbI₃ QD films exhibit improved optoelectronic properties, which enables the fabrication of a pure red PeLED with a peak external quantum efficiency (EQE) of 6.4% and a stable EL emission centered at the wavelength of 630 nm. Our reported sequential ligand post-treatment strategy opens a new route to improve the stability and efficiency of PeLEDs based on QDs.

[Summary and prospect of early warning models and systems for infectious disease outbreaks]

This paper summarizes the basic principles and models of early warning for infectious disease outbreaks, introduces the early warning systems for infectious disease based on different data sources and their applications, and discusses the application potential of big data and their analysing techniques, which have been studied and used in the prevention and control of COVID-19 pandemic, including internet inquiry, social media, mobile positioning, in the early warning of infectious diseases in order to provide reference for the establishment of an intelligent early warning mechanism and platform for infectious diseases based on multi-source big data.

[Financing strategies and cost estimates of influenza vaccination for the elderly in China: explore a multi-party co-payment mechanism]

The disease burden and economic burden of seasonal influenza is substantial in China, and the Coronavirus disease 2019 (COVID-19) pandemic has brought new challenges to the prevention and control of influenza. As a priority group of influenza vaccination, the elderly are at higher risk of influenza-associated severe symptoms and deaths, and they are more price-sensitive vaccine users with better cost-effectiveness of vaccination program. Therefore, a reasonable financing mechanism of influenza vaccination should be designed for the elderly to increase their vaccination rate. This study proposes three financing strategies of influenza vaccination for the elderly in China, trying to explore the distribution of vaccination costs among individuals, central government and local governments under different financing strategies, including the individual-central-local mechanism (strategy 1), the central-local mechanism (strategy 2), and the local payment mechanism (strategy 3). Strategy 1 is feasible and sustainable for most regions in the short term. Strategy 2 is conducive to further increasing the vaccine coverage rate of the elderly. Strategy 3 encourages local fiscal payments to help relieve the financial pressure of the central government. The results revealed a relatively heavy financial burden of influenza vaccination for the elderly, and it is recommended to promote the development of a multiparty co-payment mechanism gradually based on local conditions.

Chiral Phosphine-Copper Iodide Hybrid Cluster Assemblies for Circularly Polarized Luminescence

Chiral chromophores and their ordered assemblies are intriguing for yielding circularly polarized luminescence (CPL) and exploring intrinsic structure-light emission relationships. With the extensively studied chiral organic molecules and inorganic nanoparticle assemblies for the amplified CPL, the assemblies of copper halide hybrid clusters have attracted intensive attention due to their potential efficient CPL. Here, we report robust chiral phosphine-copper iodide hybrid clusters and their layered assemblies in crystalline states for amplified CPL. We reveal that the intermolecular interactions endow the clusters with the capability of assembling into chiral crystalline CPL materials, including hexagonal platelet-shaped microcrystals (g_lum ≈ 9.5 × 10^-3) and highly oriented crystalline films (g_lum ≈ 5 × 10^-3). Owing to the high crystalline feature of the thin film, we demonstrate an electroluminescent device with bright electroluminescence (1200 cd m^-2).

[Evaluation of demand of resources for laboratory testing and prevention and control of COVID-19 in the context of global pandemic]

Objective: To rapidly evaluate the level of healthcare resource demand for laboratory testing and prevention and control of corona virus disease 2019 (COVID-19) in different epidemic situation, and prepare for the capacity planning, stockpile distribution, and funding raising for infectious disease epidemic response. Methods: An susceptible, exposed, infectious, removed infectious disease dynamics model with confirmed asymptomatic infection cases and symptomatic hospitalized patients was introduced to simulate different COVID-19 epidemic situation and predict the numbers of hospitalized or isolated patients, and based on the current COVID-19 prevention and control measures in China, the demands of resources for laboratory testing and prevention and control of COVID-19 were evaluated. Results: When community or local transmission or outbreaks occur and total population nucleic acid testing is implemented, the need for human resources is 3.3-89.1 times higher than the reserved, and the current resources of medical personal protective equipment and instruments can meet the need. The surge in asymptomatic infections can also increase the human resource demand for laboratory testing and pose challenge to the prevention and control of the disease. When vaccine protection coverage reach ≥50%, appropriate adjustment of the prevention and control measures can reduce the need for laboratory and human resources. Conclusions: There is a great need in our country to reserve the human resources for laboratory testing and disease prevention and control for the response of the possible epidemic of COVID-19. Challenges to human resources resulted from total population nucleic acid testing and its necessity need to be considered. Conducting non-pharmaceutical interventions and encouraging more people to be vaccinated can mitigate the shock on healthcare resource demand in COVID-19 prevention and control.

Bright and Near-Unity Polarized Light Emission Enabled by Highly Luminescent Cu2I2-Dimer Cluster-Based Hybrid Materials

As one fundamental property of light, polarization has a huge impact in quantum optics and optoelectronics through light-matter interactions. However, the bright and near-unity polarized light emissions in the visible range by solid crystalline materials are scantly realized. Here, we report well-defined quasi two-dimensional (2D) hybrid crystals based on the linear alignment of Cu₂I₂-dimer/bidentate ligand hybrid clusters for achieving bright and near-unity linearly polarized light emissions. Using first-principle calculations, we demonstrate that the superaligned transition dipole moments are the key for the observed excellent polarized light emissions. To further enhance the photoluminescence (PL) polarization degree, we fabricate Cu₂I₂-dimer-based hybrid nanobelts, which display high PL quantum yield (up to 64%) and ultrahigh PL polarization degree (∼0.99). Our reported copper iodine cluster-based luminescent hybrid materials for bright and highly polarized light emissions will have great potential for future quantum optics applications.

[Promote multidisciplinary integration, and strengthen capacities on prevention, control and pandemic preparedness of influenza]

Series of the studies and consensus on the basic research on seasonal and animal influenza virus, clinical characteristics of patients with pneumonia caused by influenza A (H1N1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), disease burden of influenza, and promotion of influenza vaccination for the elderly were published in this special issue, aiming to describe the feature of influenza virological and clinical characteristics, health and economic burden, and vaccination. These researches emphasized the importance of the integration between basic medicine, clinical medicine, public health and preventive medicine in the prevention and control of infectious diseases. Based on the concept of population medicine, promoting the integration of multidisciplinary and strengthening prevention, control and pandemic preparedness on influenza, corona virus disease 2019 and other infectious diseases, could consolidate the foundation of surveillance and early warning, prevention and control, diagnosis and treatment of emerging infectious diseases, as well as improve the ability of emergency preparedness for public health events.

[Analysis on seasonality, age distribution of influenza B cases and matching degree of influenza B vaccine in China, 2011-2019]

Objective: To analyze the seasonality, age distribution of influenza B cases and matching degree of influenza B vaccine in China from 2011 to 2019, and provide evidences for the future surveillance, estimation of disease burden of influenza B, application of quadrivalent vaccines, and development of vaccine strategies. Methods: The epidemiological and virological surveillance data of influenza B from week 14 of 2011 to week 13 of 2019 obtained from National Influenza Surveillance Network were used to draw hot spot maps and conduct descriptive statistics to analyze the seasonality and age distribution of influenza B cases. The published antigenicity analysis results from the China Weekly Influenza Report were used to analyze the matching degree between the trivalent vaccine strain and the circulating influenza B strains. Results: From 2011 to 2019, the incidence of influenza B showed obvious seasonal characteristics, and influenza B virus co-circulated with influenza A virus in six winter-spring seasons, and influenza B virus/Victoria and Yamagata lineages circulated alternately. In some southern provinces, two lineages co-circulated in some southern areas in certain years. The age distribution of influenza B cases was double-peaked, and both lineages had the highest positive rate in age-group 5-15 years, with peaks at age of 10 years; B/Victoria virus had a sub-peak in age-group 25-35 years; B/Yamagata virus had a sub-peak in age-group 55-65 years. Trivalent influenza vaccine strain and influenza B epidemic strains mismatched in 2015-2016 and 2017-2018 seasons, matched in 2011-2012, 2012-2013, 2013-2014, 2014-2015 and 2016-2017 seasons, and moderately matched in 2018-2019 season, but reactivity was low. Conclusions: Influenza B mainly occurred in winter-spring season in China, and its intensity was lower than that of influenza A. There was a difference in the age distribution of the cases among different virus strains. Trivalent influenza vaccine strains and influenza B epidemic strains mismatched in several seasons. It is crucial to conduct continuous surveillance of influenza B and disease burden evaluation, improve vaccine immunization strategy, increase influenza vaccination rate to reduce the harm of influenza B in high-risk groups.

[Establishment of multi-point trigger and multi-channel surveillance mechanism for intelligent early warning of infectious diseases in China]

This paper reviews the limitations of current infectious disease surveillance and early warning system in China, analyzes the concepts and countermeasures of the establishment of an intelligent early warning platform of infectious diseases based on multi-point trigger mechanism and multi-channel surveillance mechanism and proposes the realization routes for the purpose of facilitating capacity building and improvement of surveillance and early warning of infectious diseases in China.

[Pilot surveillance and evaluation of influenza-like illness based on automatic computer analysis of electronic medical record in sentinel hospital]

Objective: To compare the accuracy of influenza-like illness (ILI) surveillance by automatic computer analysis based on electronic medical records and by doctor's report. Methods: A total of 3 542 patients who presented to Yichang Central Hospital fever clinic, respiratory department or emergency department between April to October 2019 with an ICD-10 code for acute respiratory illness (J00-J22) and complete electronic medical information of ILI related syndromes were drawn as the study sample. Taking the classification of the study sample according to the ILI case definition by influenza surveillance professionals as the gold standard, draw the receiver operating characteristic (ROC) curve and calculate sensitivity, specificity, diagnostic consistency to compared the accuracy of ILI surveillance by automatic computer analysis and by doctor's report. Results: Median age of 3 542 cases was 30 (24, 38) years old; 1 179 cases (33.29%) compliance with the case definition, ILI reported by doctors was 1 306 cases (36.87%), and computer automatic identification ILI were 1 150 cases (32.47%); 1 391 (39.27%) cases were men. The results of automatic computer analysis and doctor report consistency of kappa values with gold standard judgment were 0.97 and 0.66 respectively; area under the ROC curve was 0.98 and 0.84, respectively. And the sensitivity and specificity of automatic computer analysis were higher than that of doctor's report (all P values were <0.001), the sensitivity was 96.95% and 82.27%, and the specificity was 99.70% and 85.78%, respectively. Conclusion: The automatic computer analysis based on electronic medical records can identified ILI cases with good sensitivity and specificity in ILI case surveillance.

[Early containment strategies and core measures for prevention and control of novel coronavirus pneumonia in China]

In December 2019, novel coronavirus pneumonia epidemic occurred in Wuhan, Hubei Province, and spread rapidly across the country. In the early stages of the epidemic, China adopted the containment strategy and implemented a series of core measures around this strategic point, including social mobilization, strengthening case isolation and close contacts tracking management, blocking epidemic areas and traffic control to reduce personnel movements and increase social distance, environmental measures and personal protection, with a view to controlling the epidemic as soon as possible in limited areas such as Wuhan. This article summarizes the background, key points and core measures in the country and provinces. It sent prospects for future prevention and control strategies.

[Cost-effectiveness of potential government fully-funded influenza vaccination in population with diabetes in China]

Objective: To evaluate the cost-effectiveness of potential government fully-funded influenza vaccination for diabetics in our country. Methods: From the societal perspective, a decision tree model was developed to compare outcomes (including impact on the influenza-related outpatient consultation, hospitalization and excess mortality, and quality-adjusted life years (QALY), as well as incremental cost-effectiveness ratio (ICER)) of a national fully-funded vaccination programme in the population with diabetes and status quo (i.e., vaccinated with out-of-pocket payment, with a uptake rate of zero), using the published data with regarding to influenza related ILI (influenza-like illness) consultation rate, hospitalization rate and excess mortality rate, health-related quality of life and economic burden, diabetes prevalence, population size, health seeking behaviour, vaccine uptake rate, vaccine efficacy/effectiveness, etc. A time horizon of 1 year was used in the present analysis, and all costs were expressed in CNY in 2016 using the consumer price index. All results are presented in M (P(25), P(75)). Results: In the scenario of 40% vaccination coverage in the population with diabetes, government fully-funded vaccination programme was estimated to cost 1.71 (1.67, 1.75) billions CNY, and expected to prevent 110 000 (81 000, 143 000) influenza-related ILI consultations, 36 000 (28 000, 44 000) influenza-related SARI hospitalizations and 12 000 (9 000, 16 000) influenza-related deaths due to respiratory and cardiovascular diseases. A total of 108 000 (82 000, 142 000) QALY were estimated to be gained. The ICER was 10 088 (7 365, 14 046) CNY per QALY gained. The probability of cost-effectiveness of the fully-funded vaccination programme was 99.1% at a threshold of 53 680 CNY per QALY gained (GDP per capita in 2016). Conclusion: Government fully-funded influenza vaccination in population with diabetes is cost-effective, and thus is recommended as the key strategy of diabetes prevention and control.

[Evaluation of the application of moving epidemic method on making influenza epidemic thresholds in the 7 climate zones in China]

Objective: We planned to evaluate the effectiveness of moving epidemic method (MEM) in calculating influenza epidemic threshold of 7 climatic zones in China mainland. Methods: The positive rate of influenza virus was obtained from the National Influenza Surveillance Network System from 2010/2011 to 2017/2018. We divided the 31 provinces into 7 climatic zones according to previous literatures and applied MEM to calculate the influenza epidemic threshold of 2018/2019 influenza season for these climatic zones. Sensitivity, specificity, positive predictive value and negative predictive value were calculated to evaluate the effectiveness of MEM. Results: Pre-epidemic threshold (the positive rate of influenza virus) varied from 9.66% (temperate zone) to 16.36% (subtropical zone) for 2018/2019 influenza season. The gap between pre-epidemic and post-epidemic thresholds was less than 5% except for plateau zone. The sensitivity was 86.16% (95CI:66.81%-98.23%), the specificity was 94.92% (95CI: 91.13%-98.41%), the positive predictive value was 89.87% (95%CI: 84.39%-94.38%), the negative predictive value was 92.96% (95%CI: 84.46%-99.17%). Conclusion: Overall, moving epidemic Method performs well in calculating influenza epidemic threshold in China, much better than the previous study.

[A survey on the current status and related factors of influenza vaccination among health care workers in tertiary hospitals of Xining city during the influenza epidemic season from 2017 to 2018]

Objective: To evaluate the current status and related factors of influenza vaccination among health care workers (HCWs) in tertiary hospitals of Xining city after the implementation of the free influenza vaccination policy. Methods: In August 2018, the cluster sampling method was used to select four medical institutions in Xining that had previously conducted investigations and interventions. All HCWs(excluding logistic staff) in each medical institution were included in the study. A total of 3 260 valid respondents were included. Questionnaires were used to collect the demographic characteristics, influenza and influenza vaccination awareness, implementation of free policy in the influenza epidemic season from 2017 to 2018, influenza vaccination status, awareness of influenza vaccination schedule and free policy. The multivariate logistic regression model was used to analyze related factors of influenza vaccination. Results: The age of respondents was (31.41±5.00) years. The influenza vaccination rate was 6.80% (226/3 260) in 2017-2018 influenza epidemic season. After controlling for related factors, the awareness of the influenza vaccination schedule (OR=17.05, 95%CI: 5.86-49.59), vaccination frequency (OR=8.22, 95%CI: 2.98-22.61) and the free policy (OR=3.15, 95%CI: 1.49-6.67) had higher vaccination rate. Conclusion: The influenza vaccination rate of HCWs in tertiary hospitals of Xining city was low. Increasing the awareness of the vaccination schedule, frequency and free policy may promote the influenza vaccination rate of HCWs.

[Current situation and related policies on the implementation and promotion of influenza vaccination among health care workers]

Health care workers have higher risk of influenza infection because of their occupational exposure to infected patients. Infection of the health care workers may not only result in the increasing risk of the nosocomial infection and family transmission, but also disrupt the health services due to absence from work. Health care workers were recommended as a priority group of influenza vaccinationin more than 40 countries and regions in the world. In recent years, domestic surveys show that the influenza vaccine coverage among health care workers was low. This paper outlines the current status and related policies of influenza vaccination among health care workers in China and global. Additionally, we analyzed and discussed the proper immunization strategy of influenza vaccine for medical staff in China.

[Cost-effective analysis of seasonal influenza vaccine in elderly Chinese population]

Objective: To evaluate the cost-effectiveness of seasonal influenza vaccination, compared to no vaccination, for the elderly aged ≥60 years old in China. Methods: A static life-time Markov model is conducted to simulate the Chinese elderly population aged ≥60 years old. Taking the health care system perspective, one-year analytic cycle length is used for each influenza season. The model was assumed to be repeated until the individual reaches 100 years old. Three interventions were evaluated, including no vaccination, annual trivalent influenza vaccination, and annual quadrivalent influenza vaccination. Using the threshold of 3 times GDP per capita per Quality-adjusted life year (QALY) (193 932/QALY), the incremental cost-effectiveness ratio (ICER) was calculated to compare the cost-effectiveness of every two interventions.Model inputs like data for costs and utilities were from studies on Chinese population if they were available. QALY was used to measure health utility. One-way sensitivity analysis and probabilistic sensitivity analysis were adopted to quantify the level of confidence of the model output. Results: The total influenza associated costs of no vaccination would be 603 CNY per person, while the total costs of annual trivalent vaccination would be 1 027 CNY. Using trivalent vaccine would result in 0.007 QALY gained per person compared to no vaccination, with an increased cost of 424 CNY per person. The ICER of trivalent vaccination over no vaccination for all the elderly population in China would be 64 026 CNY per QALY gained, which was less than the threshold of 3 times GDP per capita. The total costs of annual quadrivalent vaccination would be 1 988 CNY. Using quadrivalent vaccine would result in 0.008 additional QALY gained per person compared to no vaccination, with an increased cost of 1 385 CNY per person. The ICER of quadrivalent vaccination over no vaccination would be 174 081 CNY per QALY gained, which was less than the threshold of 3 times GDP per capita. Conclusion: Vaccinating elderly population would improve health utilities at higher health care costs for the elderly. Using the threshold of 3 times GDP per capita per QALY (193 932/QALY), both trivalent and quadrivalent vaccination would be cost-effective compared to no vaccination in elderly Chinese population.

[The mortality burden of influenza in China: a systematic review]

Objective: To systematically review the mortality burden study of influenza in mainland China. Method: "influenza", "flu", "H1N1", "pandemic", "mortality", "death", "fatality", "burden", "China" and "Chinese" were used as keywords, and a systematic literature search was conducted to identify articles in three English databases (PubMed, Web of Science and Embase) and three Chinese database (CNKI, WanFang and VIP) during 1990-2018 (excluding Hong Kong, Macao and Taiwan). The language of literature was restricted to Chinese and English. The inclusion criteria were human-oriented researches with method based on population, and research indexes included mortality and excess mortality. The exclusion criteria were non-primary research materials, predictive research and research on the burden of avian influenza related deaths. A total of 17 literatures were included, and the basic information to descriptive characteristics, methodology of modeling and the corresponding results were extracted. Results: All the 17 studies adopted indirect statistical models, with 14 of which adopted the regression model, and all the research index was excess mortality. All causes (16 studies), respiratory and circulatory diseases (14 studies) and pneumonia and influenza (10 studies) were the main causes of death associated with influenza. Influenza associated mortality burden in the elderly was higher, with the lowest excess mortality rates of all causes, respiratory and circulatory diseases, pneumonia and influenza being 49.57, 30.80 and 0.69 per 100 000 people, and the highest rates being 228.16, 170.20 and 30.35 per 100 000 people, respectively. In the non-elderly, the corresponding lowest rates were -0.27, -0.08 and 0.04 per 100 000 people respectively, and the highest rates were 3.63, 2.6 and 0.91 per 100 000 people, respectively. The influenza-related excess mortality was higher in the north, with a minimum of 7.8 per 100 000 and a maximum of 18.0 per 100 000, and slightly lower in the south, with a minimum of 6.11 per 100 000 and a maximum of 18.7 per 100 000. There were also differences in deaths caused by different influenza virus subtypes, with influenza A(H3N2) and influenza B virus possibly posing a heavier mortality burden. Conclusions: Studies on influenza mortality burden is mainly based on indirect model and urban level in China. The mortality burden of influenza in the elderly, the northern and subtype A(H3N2) and B were more severe.

[A systematic review of the economic burden of influenza in China]

Objectives: To understand the status of studies about influenza economic burden in mainland China and summarize their major results. Methods: The words of influenza, flu, cost, economic, burden, effectiveness, benefit, utility, China, and Chinese, were used as search keywords. Journal papers published during 2000-2018 were searched from Chinese electronic databases (CNKI and Wanfang) and English electronic databases (PubMed, Web of science, EconLit and Cochrane Library). The language of literature was restricted to Chinese and English. A total of 23 effective documents were included, and the descriptive characteristics, research indexes and methods included in the literature were analyzed. The monetary unit used in this review is Chinese Yuan (CNY). Results: The 23 study sites were mainly in the relatively developed and populous regions. The total cost per capita of laboratory-confirmed influenza,of all age-group was reported in 6 literatures, and only 4 literatures reported it in out-patients (range: 768.0-999.9 CNY), Only one study reported this indicator in inpatients (9 832.0 CNY). One literature reported the total cost per capita of influenza-like illness,, which was 205.1 CNY. And one literature reported that the direct medical cost of inpatients per capita in children under 5 years of age was 6 072.0 CNY while two literature reported this index for the elderly over 60 years of age, ranging from 14 250.0 to 19 349.1 CNY. Four articles reported the economic burden of influenza in urban and rural areas, one of which showed that the related expenses of urban influenza inpatients accounted for 31% of the average annual income, while which for the rural flow was 113%. Conclusion: The average economic burden of lab-confirmed influenza case is higher than that of influenza-like illness, and there are differences in outpatient indirect expenses and inpatients direct medical expenses. The direct medical burden for the hospitalized 60-years-and-beyond influenza case group is heavier thar other age group. By region, the influenza associated individual economic burden in rural area is higher than that of urban area..

[Estimates of influenza-associated excess mortality by three regression models in Shanxi Province during 2013-2017]

Objective: Using three models too estimate excess mortality associated with influenza of Shanxi Province during 2013-2017. Methods: Mortality data and influenza surveillance data of 11 cities of Shanxi Province from the 2013-2014 through 2016-2017 were used to estimate influenza-associated all cause deaths, circulatory and respiratory deaths and respiratory deaths. Three models were used: (i) Serfling regression, (ii)Poisson regression, (iii)General line model. Results: The total reported death cases of all cause were 157 733, annual death cases of all cause were 39 433, among these cases, male cases 93 831 (59.50%), cases above 65 years old 123 931 (78.57%). Annual influenza-associated excess mortality, for all causes, circulatory and respiratory deaths, respiratory deaths were 8.62 deaths per 100 000, 6.33 deaths per 100 000 and 0.68 deaths per 100 000 estimated by Serfling model, respectively; and 21.30 deaths per 100 000, 16.89 deaths per 100 000 and 2.14 deaths per 100 000 estimated by General line model, respectively; and 21.76 deaths per 100 000, 17.03 deaths per 100 000 and 2.05 deaths per 100 000, estimated by Poisson model, respectively. Influenza-related excess mortality was higher in people over 75 years old; influenza-associated excess mortalityfor all causes, circulatory and respiratory deaths, respiratory deaths were 259.67 deaths per 100 000, 229.90 deaths per 100 000 and 32.63 deaths per 100 000, estimated by GLM model, respectively; and 269.49 deaths per 100 000, 233.69 deaths per 100 000 and 31.27 deaths per 100 000, estimated by Poisson model,respectively. Conclusion: Excess mortality associated with influenza mainly caused by A (H3N2), Influenza caused the most associated death amongold people.

[Technical guidelines for seasonal influenza vaccination in China, 2018-2019]

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and its complications. Currently, China has licensed trivalent (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. In most parts of China, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients need to pay for it. To strengthen the technical guidance for prevention and control of influenza and the operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC), Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" , based on most recent existing scientific evidences. The main updates include: epidemiology and disease burden of influenza, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, and, IIV3 and IIV4 vaccines'major immune responses, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The recommendations include: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for any influenza vaccine product for persons who can accept ≥1 licensed, recommended, and appropriate products. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-60 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to pregnant during the influenza season. Children aged 6 months to 8 years old require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in previous influenza season, 1 dose is recommended. People ≥ 9 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. Influenza vaccination should continue to be available for those unable to be vaccinated before the end of October during the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for CDC members who are working on influenza control and prevention, PoVs members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and members of maternity and child care institutions at all levels.

[Comparison of epidemiological characteristics of human infection with avian influenza A (H5N1) virus in five countries of Asia and Africa]

Objective: To understand characteristics of demographic, seasonal and spatial distribution of H5N1 cases in major countries of Asia (Indonesia, Cambodia, Vietnam, China) and Africa (Egypt). Methods: Through searching public data resource and published papers, we collected cases information in five countries from May 1st, 1997 to November 6th, 2017, including general characteristics, diagnosis, onset and exposure history, etc. Different characteristics of survived and death cases in different countries were described and χ(2) test was used to compare the differences among death cases and odds ratio (OR) and 95%CI value was used to compare death risk in different countries. Results: A total of 856 cases were reported in five countries with Egypt had the most cases (44.3%). The highest number of cases were reported in 2015 (18.3%). 53% cases were reported from January to March, and 96.1% of cases had the history of poultry exposure. 64.2% (43 cases) cases in China had live poultry market exposure, but the sick/dead poultry exposure was the major exposure for cases in other four countries. 452 death cases were reported in five countries, and the fatality rate was 52.8%. With Egypt as the reference group, the highest death risk was seen in Indonesia (OR (95%CI): 11.52 (7.46-17.77)), followed by Cambodia (OR (95%CI): 4.27(2.37-7.69)) and China (OR (95%CI): 2.87 (1.73-4.74)). The age distribution of death cases among 5 countries was statistically significant, and the highest fatality rate was in 15-54 years group in Egypt (83.6%, 102 cases), while in Cambodia the highest fatality rate was in 0-14 years group (76.9%, 30 cases). The highest number of deaths were reported in 2006, and 48.3% were reported from January to March. There was difference in exposure routes among 5 countries (χ(2)=43.85, P=0.001), 63.2% (24 cases) of the death cases in China had live poultry market exposure. 92.9% (79 cases), 83.3% (40 cases) and 100.0% (38 cases) death cases in Indonesia, Vietnam and Camodia had sick/dead poultry exposure, respectively;and 81.6% (31 cases) of the death cases in Egypt had backyard poultry exposure. Conclusion: The geographical distribution, seasonal age, gender, exposure matter and outcome of H5N1 cases in five countries were different.

[Technical guidelines for seasonal influenza vaccination in China (2018-2019)]

Seasonal influenza vaccination is the most effective way to prevent influenza virus infection and complications from infection. Currently, China has licensed trivalent inactivated influenza vaccine (IIV3) and quadrivalent inactivated influenza vaccine (IIV4), including split-virus influenza vaccine and subunit vaccine. Except for a few major cities, influenza vaccine is a category Ⅱ vaccine, which means influenza vaccination is voluntary, and recipients must pay for it. To strengthen the technical guidance for prevention and control of influenza and operational research on influenza vaccination in China, the National Immunization Advisory Committee (NIAC) Influenza Vaccine Technical Working Group (TWG), updated the 2014 technical guidelines and compiled the "Technical guidelines for seasonal influenza vaccination in China (2018-2019)" . The main updates in this version include: epidemiology, disease burden, types of influenza vaccines, northern hemisphere influenza vaccination composition for the 2018-2019 season, IIV3 and IIV4 immune response, durability of immunity, immunogenicity, vaccine efficacy, effectiveness, safety, cost-effectiveness and cost-benefit. The influenza vaccine TWG provided the recommendations for influenza vaccination for the 2018-2019 influenza season based on existing scientific evidence. The recommendations described in this report include the following: Points of Vaccination clinics (PoVs) should provide influenza vaccination to all persons aged 6 months and above who are willing to be vaccinated and do not have contraindications. No preferential recommendation is made for one influenza vaccine product over another for persons for whom more than one licensed, recommended, and appropriate product is available. To decrease the risk of severe infections and complications due to influenza virus infection among high risk groups, the recommendations prioritize seasonal influenza vaccination for children aged 6-59 months, adults ≥60 years of age, persons with specific chronic diseases, healthcare workers, the family members and caregivers of infants <6 months of age, and pregnant women or women who plan to become pregnant during the influenza season. Children aged 6 months through 8 years require 2 doses of influenza vaccine administered a minimum of 4 weeks apart during their first season of vaccination for optimal protection. If they were vaccinated in 2017-2018 influenza season or a prior season, 1 dose is recommended. People more than 8 years old require 1 dose of influenza vaccine. It is recommended that people receive their influenza vaccination by the end of October. Influenza vaccination should be offered as soon as the vaccination is available. For the people unable to be vaccinated before the end of October, influenza vaccination will continue to be offered for the whole season. Influenza vaccine is also recommended for use in pregnant women during any trimester. These guidelines are intended for use by staff members of the Centers for Disease Control and Prevention at all levels who work on influenza control and prevention, PoVs staff members, healthcare workers from the departments of pediatrics, internal medicine, and infectious diseases, and staff members of maternity and child care institutions at all levels.

[Current situation and challenges on the implementation of prevention and control programs regarding the seasonal influenza, in China]

In China, the control and prevention programs on any disease has always been based on comprehensive strategies. Take influenza as an example, related contents would include: strengthening the surveillance, recommendation and promotion of vaccination, rational use of antiviral drugs, conducting outbreak investigation and control, and publicizing individual protective measures, etc. In terms of the response to challenges, specific proposals would include: adjustment of case reports, optimization of surveillance systems, reinforcement of vaccination recommendation by health care workers, improvement of access to vaccination, development of rapid diagnostic reagents, and rational use of antiviral drugs, etc.