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A(H1N1)
Influenza A virus subtype H1N1 (A/H1N1) is a subtype of influenza A virus (IAV). Some human-adapted strains of H1N1 are endemic in humans and are one cause of seasonal influenza (flu). Other strains of H1N1 are endemic in pigs (swine influenza) and in birds (avian influenza). Subtypes of IAV are defined by the combination of the antigenic H and N proteins in the viral envelope; for example, "H1N1" designates an IAV subtype that has a type-1 hemagglutinin (H) protein and a type-1 neuraminidase (N) protein. All subtypes of IAV share a Sense (molecular biology), negative-sense, segmented RNA virus, RNA genome. Under rare circumstances, one strain of the virus can acquire genetic material through Reassortment, genetic reassortment from a different strain and thus evolve to acquire new characteristics, enabling it to evade host immunity and occasionally to jump from one species of host to another. Major outbreaks of H1N1 strains in humans include the Spanish flu, 1918 Spanish flu p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2009 Flu Pandemic
The 2009 swine flu pandemic, caused by the H1N1/swine flu/influenza virus and declared by the World Health Organization (WHO) from June 2009 to August 2010, was the third recent flu pandemic involving the H1N1 virus (the first being the 1918–1920 Spanish flu pandemic and the second being the 1977 Russian flu). The first identified human case was in La Gloria, Mexico, a rural town in Veracruz. The virus appeared to be a new strain of H1N1 that resulted from a previous triple reassortment of bird, swine, and human flu viruses which further combined with a Eurasian pig flu virus, leading to the term " swine flu". Unlike most strains of influenza, the pandemic H1N1/09 virus did not disproportionately infect adults older than 60 years; this was an unusual and characteristic feature of the H1N1 pandemic. Even in the case of previously healthy people, a small percentage develop pneumonia or acute respiratory distress syndrome (ARDS). This manifests itself as increased breath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Historical Annual Reformulations Of The Influenza Vaccine
Since 1999, the World Health Organization (WHO) has issued annual recommendations for influenza vaccine formulations. One reformulation of the influenza vaccine is for the Northern Hemisphere, and the other is for the Southern Hemisphere. Both recommendations are trivalent, i.e. featuring three strains. Since the 2012–2013 season, the WHO recommendations have also included the formulation of an annual quadrivalent vaccine, featuring an additional strain of Influenza B virus, B/Yamagata. Due to the widespread use of non-pharmaceutical interventions at the beginning of the COVID-19 pandemic, the B/Yamagata influenza lineage has not been isolated since March 2020, and may have been eradicated. Starting with the 2024 Southern Hemisphere influenza season, the WHO and other regulatory bodies have removed this strain from influenza vaccine recommendations. __TOC__ Northern Hemisphere recommended strains The following is a list of strains for the Northern Hemisphere influenza s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Influenza A Virus
''Influenza A virus'' (''Alphainfluenzavirus influenzae'') or IAV is the only species of the genus ''Alphainfluenzavirus'' of the virus family '' Orthomyxoviridae''. It is a pathogen with strains that infect birds and some mammals, as well as causing seasonal flu in humans. Mammals in which different strains of IAV circulate with sustained transmission are bats, pigs, horses and dogs; other mammals can occasionally become infected. IAV is an enveloped negative-sense RNA virus, with a segmented genome. Through a combination of mutation and genetic reassortment the virus can evolve to acquire new characteristics, enabling it to evade host immunity and occasionally to jump from one species of host to another. Subtypes of IAV are defined by the combination of the antigenic H and N proteins in the viral envelope; for example, "H1N1" designates an IAV subtype that has a type-1 hemagglutinin (H) protein and a type-1 neuraminidase (N) protein. Almost all possible combinations of H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pandemic H1N1/09 Virus
The pandemic H1N1/09 virus is a swine origin influenza A virus subtype H1N1 virus strain, strain that was responsible for the 2009 swine flu pandemic. This strain is often called swine flu by the public media due to the prevailing belief that it originated in pigs. The virus is believed to have originated around September 2008 in central Mexico. The H1N1 pandemic of 2009 was the first public health emergency of international concern designated by the World Health Organization. While H1N1/09 was the primary strain of flu seen that year, it was not unusually contagious or lethal. Most cases were mild, although those who had to be hospitalized were often severely ill. In the fall of 2009, between 15 and 33% of those hospitalized with H1N1 in the Southern Hemisphere were taken to the ICU. One clinician remarked that the pandemic was "like two diseases" because of the stark difference between mild and severe cases, with few falling in between. Viral characteristics The virus is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World Health Organization
The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Geneva, Switzerland, and has 6 regional offices and 150 field offices worldwide. Only sovereign states are eligible to join, and it is the largest intergovernmental health organization at the international level. The WHO's purpose is to achieve the highest possible level of health for all the world's people, defining health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." The main functions of the World Health Organization include promoting the control of epidemic and endemic diseases; providing and improving the teaching and training in public health, the medical treatment of disease, and related matters; and promoting the establishment of international standards for biologic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Avian Influenza
Avian influenza, also known as avian flu or bird flu, is a disease caused by the influenza A virus, which primarily affects birds but can sometimes affect mammals including humans. Wild aquatic birds are the primary host of the influenza A virus, which is enzootic (continually present) in many bird populations. Symptoms of avian influenza vary according to both the strain of virus underlying the infection, and on the species of bird or mammal affected. Classification of a virus strain as either low pathogenic avian influenza (LPAI) or high pathogenic avian influenza (HPAI) is based on the severity of symptoms in domestic chickens and does not predict severity of symptoms in other species. Chickens infected with LPAI display mild symptoms or are asymptomatic, whereas HPAI causes serious breathing difficulties, significant drop in egg production, and sudden death. Domestic poultry may potentially be protected from specific strains of the virus by vaccination. Humans and other ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Journal Of Epidemiology
The American Journal of Epidemiology (''AJE'') is a peer-reviewed journal for empirical research findings, opinion pieces, and methodological developments in the field of epidemiological research. The current editor-in-chief is Enrique Schisterman. Articles published in ''AJE'' are indexed by PubMed, Embase, and a number of other databases. The ''AJE'' offers open-access options for authors. It is published monthly, with articles published online ahead of print at the accepted manuscript and corrected proof stages. Entire issues have been dedicated to abstracts from academic meetings (Society of Epidemiologic Research, North American Congress of Epidemiology), the history of the Epidemic Intelligence Service of the Centers for Disease Control and Prevention (CDC), the life of George W. Comstock, and the celebration of notable anniversaries of schools of public health ( University of California, Berkeley, School of Public Health; Tulane University School of Public Health and Tro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leukocyte
White blood cells (scientific name leukocytes), also called immune cells or immunocytes, are cells of the immune system that are involved in protecting the body against both infectious disease and foreign entities. White blood cells are generally larger than red blood cells. They include three main subtypes: granulocytes, lymphocytes and monocytes. All white blood cells are produced and derived from multipotent cells in the bone marrow known as hematopoietic stem cells. Leukocytes are found throughout the body, including the blood and lymphatic system. All white blood cells have nuclei, which distinguishes them from the other blood cells, the anucleated red blood cells (RBCs) and platelets. The different white blood cells are usually classified by cell lineage ( myeloid cells or lymphoid cells). White blood cells are part of the body's immune system. They help the body fight infection and other diseases. Types of white blood cells are granulocytes (neutrophils, eosinoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lung
The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the atmosphere and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their musculoskeletal systems to support and foster breathing. In early tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the primary muscle that drives breathing is the Thoracic diaphragm, diaphragm. The lungs also provide airflow that makes Animal communication#Auditory, vocalisation including speech possible. Humans have two lungs, a ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytokine
Cytokines () are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are produced by a broad range of cells, including immune cells like macrophages, B cell, B lymphocytes, T cell, T lymphocytes and mast cells, as well as Endothelium, endothelial cells, fibroblasts, and various stromal cells; a given cytokine may be produced by more than one type of cell. Due to their size, cytokines cannot cross the lipid bilayer of cells to enter the cytoplasm and therefore typically exert their functions by interacting with specific cytokine receptor, cytokine receptors on the target cell surface. Cytokines are especially important in the immune system; cytokines modulate the balance between humoral immunity, humoral and cell-mediated immunity, cell-based immune responses, and they regulate the maturation, growth, and responsiveness of particular cell populations. Some cytokines enhance or inhibit the action of other cytokines in complex way ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immune System
The immune system is a network of biological systems that protects an organism from diseases. It detects and responds to a wide variety of pathogens, from viruses to bacteria, as well as Tumor immunology, cancer cells, Parasitic worm, parasitic worms, and also objects such as wood splinters, distinguishing them from the organism's own healthy biological tissue, tissue. Many species have two major subsystems of the immune system. The innate immune system provides a preconfigured response to broad groups of situations and stimuli. The adaptive immune system provides a tailored response to each stimulus by learning to recognize molecules it has previously encountered. Both use humoral immunity, molecules and cell-mediated immunity, cells to perform their functions. Nearly all organisms have some kind of immune system. Bacteria have a rudimentary immune system in the form of enzymes that protect against bacteriophage, viral infections. Other basic immune mechanisms evolved in ancien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
