The book consists of eleven chapters in three main parts. Part 1 (Chapter 1) provides a condensed record of global infectious disease pandemics. It reviews the ravages of previous global infectious disease pandemics, such as the plague, cholera, smallpox, influenza and COVID-19, and analyzes infectious disease threats which could cause pandemics, such astuberculosis, MERS, Ebola and SARS. Part 2 (Chapters 2 through 7) collates the latest scientific knowledge of pandemics. This part systematically explains pandemic pathways, pandemic challenges and threats, zoonotic spillover of pathogens, genomic sequencing- based surveillance and early warning of pathogens, the impact of climate change on pandemics, and the link between globalization and pandemics. Themain findings and conclusions are as follows.?。?) Infectious diseases with the potential for causing pandemics are characterized by strong infectivity, pathogenicity, virulence, and variability of the pathogen. The short incubation period of the disease, easy transmission routes, high susceptibility of the population and the lack of prevention andtreatment methods are the conditions for the occurrence of infectious diseasepandemics. Climatic, geographic, and social factors such as changes in modes of production and lifestyle, deforestation, increased meat consumption, healthcare and living conditions, population mobility, social stability, tourism and trade, urbanization, policy interventions, and public health services maybecome conditions for the occurrence of infectious disease pandemics. (2) There are still many challenges in the global response to emerging infectious disease pandemics. First, a unified global community of interest against pandemics has yet to be formed. Second, existing surveillancesystems fall short of early pandemic warning and response needs. Third,Executive Summary there is a lack of urgency and a lack of targeted measures early in pandemics. Fourth, pandemics overwhelm healthcare facilities, and effective drugs are often unavailable. Fifth, there is a coexistence of inequitable vaccine distribution and vaccine hesitation. Sixth, public education is ineffective, and social stigma and discrimination persist. Seventh, pandemics have squeezedprevention and control measures from other infectious diseases.?。?) Most severe infectious diseases that exact a heavy toll on humanity are caused by pathogens of animal origin. There is an enormous body of potential pandemic pathogens, but they remain poorly understood. The sources of zoonotic spillover are complex and diverse, including zoonotic spillover of pathogens from animals closely related to humans, pathogens from migratory animals, pathogens from vectors, and pathogens from animals in special habitats. Studies that consistently track pathogens’ chain of transmission between humans and animals remain sparse, making it difficult to pinpoint the spillover interface — it is difficult to determine which pathogens in nature have the potential of spillover to humans. This calls for continued, in-depth research on key factors of zoonotic spillover among potential pathogens, based on the consensus findings of scientists from multiple countries. It is recommended that research and discovery of unknown microorganisms be undertaken to assess the public health implications, a catalogue of pathogens for emerging infectious diseases in the future be proposed, and targeted research be conducted to enhancepreparedness and defense against emerging infectious diseases. (4) The advancement of genome sequencing technologies and bioinformatics has greatly improved the efficiency of pathogen identification; acceleratedthe research and development of vaccines; and provided powerful tools for the Pandemics: Challenges & Responses origin tracing, surveillance, and early warning of pathogenic microorganisms. Pathogens continue to mutate and evolve in the host and through transmission. Similarity and evolutionary analysis of pathogen genomes can help reveal possible sources and routes of transmission. Genomic sequencing technology has become an important complement to traditional epidemiological investigations. Most genomic variations do not alter the characteristics of pathogens, but a few specific mutations may significantly alter transmission characteristics, replication capacity, tissue tropism, antigenicity, drug resistance, or pathogenicity. Alterations in pathogen genomes may also render existing molecular diagnostics ineffective. Therefore, it is necessary to further track and monitor changes in pathogen genomes and adapt and update methods and strategies for testing, prevention and control, and treatment inreal time to achieve precise prevention and control during epidemics.?。?) Climate change has an important impact on infectious disease pandemics. Climate and environmental factors can alter the spatial and temporal distribution of vector organisms and the migration patterns of biotic populations, affecting disease transmission patterns. They can also expand the reach of diseases by altering the mechanisms of pathogen reproduction and transmission, as well as host immunity and the behaviors of susceptible populations. Global warming, the resulting changes in precipitation patterns, and the frequency of extreme weather events may raise the risk of additional climate-sensitive infectious disease pandemics in the future. Climate and environmental factors have also played an important role in the COVID-19 pandemic. To address the risk of future infectious disease pandemics, different regions and sectors must work together to monitor the spatial andtemporal dynamics of infectious disease vectors under changing climate
Pandemic Threats / 001 I. The Plague / 002 II. Cholera / 005 III. Smallpox / 008 IV. Influenza / 011 V. COVID-19 / 019 VI. Other infectious diseases that may cause pandemics / 019 References / 022
How Pandemics Arise / 027 I. Characteristics of pandemics and determination criteria / 027 II. Characteristics of pandemic-inducing infectious diseases / 029 III. Factors contributing to pandemics of infectious diseases / 034 References / 047
The Challenges of Pandemics / 053 I. Absence of a unified global community of interest / 054 II. Monitoring systems insufficient for early warning and response / 055