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Targeted Immunization Strategies
Targeted immunization strategies are approaches designed to increase the immunization level of populations and decrease the chances of epidemic outbreaks. Though often in regards to use in healthcare practices and the administration of vaccines to prevent biological epidemic outbreaks, these strategies refer in general to immunization schemes in complex networks, biological, social or artificial in nature. Identification of at-risk groups and individuals with higher odds of spreading the disease often plays an important role in these strategies, since targeted immunization in high-risk groups is necessary for effective eradication efforts and has a higher return on investment than immunizing larger but lower-risk groups. Background The success of vaccines in preventing major outbreaks relies on the mechanism of herd immunity, also known as community immunity, where the immunization of individuals provides protection for not only the individuals, but also the community at lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunization
Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the antigen, immunogen). When this system is exposed to molecules that are foreign to the body, called ''non-self'', it will orchestrate an immune response, and it will also develop the ability to quickly respond to a subsequent encounter because of immunological memory. This is a function of the adaptive immune system. Therefore, by exposing a human, or an animal, to an immunogen in a controlled way, its body can learn to protect itself: this is called active immunization. The most important elements of the immune system that are improved by immunization are the T cells, B cells, and the Antibody, antibodies B cells produce. Memory B cells and memory T cells are responsible for a swift response to a second encounter with a foreign molecule. Passive immunization is direct introduction of these elements into the body, instead of production of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scale-free Networks
A scale-free network is a network whose degree distribution follows a power law, at least asymptotically. That is, the fraction ''P''(''k'') of nodes in the network having ''k'' connections to other nodes goes for large values of ''k'' as : P(k) \ \sim \ k^\boldsymbol where \gamma is a parameter whose value is typically in the range 2<\gamma<3 (wherein the second moment ( scale parameter) of is infinite but the first moment is finite), although occasionally it may lie outside these bounds. The name "scale-free" could be explained by the fact that some moments of the degree distribution are not defined, so that the network does not have a characteristic scale or "size". Preferential attachment and the [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epidemiology
Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and Risk factor (epidemiology), determinants of health and disease conditions in a defined population, and application of this knowledge to prevent diseases. It is a cornerstone of public health, and shapes policy decisions and evidence-based practice by identifying Risk factor (epidemiology), risk factors for disease and targets for preventive healthcare. Epidemiologists help with study design, collection, and statistical analysis of data, amend interpretation and dissemination of results (including peer review and occasional systematic review). Epidemiology has helped develop methodology used in clinical research, public health studies, and, to a lesser extent, basic research in the biological sciences. Major areas of epidemiological study include disease causation, transmission (medicine), transmission, outbreak investigation, disease surveillance, environmental epidemiology, forensic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ILOVEYOU
ILOVEYOU, sometimes referred to as the Love Bug or Loveletter, was a computer worm that infected over ten million Windows personal computers on 4 May 2000 and after 5 May 2000. It started spreading as an email message with the subject line "ILOVEYOU" and the attachment "LOVE-LETTER-FOR-YOU.TXT.vbs". Windows computers often hide the latter file extension (" VBS", a type of interpreted file) by default because it is an extension for a file type that Windows knows, leading unwitting users to think it was a normal text file. Opening the attachment activates the Visual Basic script. First, the worm inflicts damage on the local machine, overwriting random files (including Office files and image files; however, it hides MP3 files instead of deleting them), then, it copies itself to all addresses in the Windows Address Book used by Microsoft Outlook, allowing it to spread much faster than any other previous email worm. Onel de Guzman, a then-24-year-old computer science student at A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infectious Diseases
infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection. Infections can be caused by a wide range of pathogens, most prominently bacteria and viruses. Hosts can fight infections using their immune systems. Mammalian hosts react to infections with an innate response, often involving inflammation, followed by an adaptive response. Treatment for infections depends on the type of pathogen involved. Common medications include: * Antibiotics for bacterial infections. * Antivirals for viral infections. * Antifungals for fungal infections. * Antiprotozoals for protozoan infections. * Antihelminthics for infections caused by parasitic worms. Infectious diseases remain a significant global health concern, causing approximately 9.2 million deaths ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poliomyelitis Eradication
Polio eradication, the goal of permanent global cessation of circulation of the poliovirus and hence elimination of the poliomyelitis (polio) it causes, is the aim of a multinational public health effort begun in 1988, led by the World Health Organization (WHO), the United Nations Children's Fund (UNICEF) and the Rotary Foundation. These organizations, along with the U.S. Centers for Disease Control and Prevention (CDC) and The Gates Foundation, have spearheaded the campaign through the Global Polio Eradication Initiative (GPEI). Successful eradication of infectious diseases has been achieved twice before, with smallpox in humans and rinderpest in ruminants. Prevention of disease spread is accomplished by vaccination. There are two kinds of polio vaccine—oral polio vaccine (OPV), which uses weakened poliovirus, and inactivated polio vaccine (IPV), which is injected. OPV is less expensive and easier to administer, and can spread immunity beyond the person vaccinated, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smallpox Eradication
Smallpox was an infectious disease caused by Variola virus (often called Smallpox virus), which belongs to the genus ''Orthopoxvirus''. The Ali Maow Maalin#Maalin's case, last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) certified the Eradication of infectious diseases, global eradication of the disease in 1980, making smallpox the only human disease to have been eradicated to date. The initial symptoms of the disease included fever and vomiting. This was followed by formation of Ulcer (dermatology), ulcers in the mouth and a skin rash. Over a number of days, the skin rash turned into the characteristic fluid-filled blisters with a dent in the center. The bumps then Wound healing#Proliferative phase, scabbed over and fell off, leaving scars. The disease was transmitted from one person to another primarily through prolonged face-to-face contact with an infected person or rarely via Fomite, contaminated objects. Prevention was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vaccine-preventable Diseases
A vaccine-preventable disease is an infectious disease for which an effective preventive vaccine exists. If a person acquires a vaccine-preventable disease and dies from it, the death is considered a vaccine-preventable death. The most common and serious vaccine-preventable diseases tracked by the World Health Organization (WHO) are: diphtheria, ''Haemophilus influenzae'' serotype b infection, hepatitis B, measles, meningitis, mumps, pertussis, poliomyelitis, rubella, tetanus, tuberculosis, and yellow fever. The WHO reports licensed vaccines being available to prevent, or contribute to the prevention and control of, 31 vaccine-preventable infections. Background In 2012, the World Health Organization estimated that vaccination prevents 2.5 million deaths each year. With 100% immunization, and 100% efficacy of the vaccines, one out of seven deaths among young children could be prevented, mostly in developing countries, making this an important global health issue. Four diseases wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunization
Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an infectious agent (known as the antigen, immunogen). When this system is exposed to molecules that are foreign to the body, called ''non-self'', it will orchestrate an immune response, and it will also develop the ability to quickly respond to a subsequent encounter because of immunological memory. This is a function of the adaptive immune system. Therefore, by exposing a human, or an animal, to an immunogen in a controlled way, its body can learn to protect itself: this is called active immunization. The most important elements of the immune system that are improved by immunization are the T cells, B cells, and the Antibody, antibodies B cells produce. Memory B cells and memory T cells are responsible for a swift response to a second encounter with a foreign molecule. Passive immunization is direct introduction of these elements into the body, instead of production of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Influenza Vaccine
Influenza vaccines, colloquially known as flu shots or the flu jab, are vaccines that protect against infection by influenza viruses. New versions of the vaccines are developed twice a year, as the influenza virus rapidly changes. While their effectiveness varies from year to year, most provide modest to high protection against influenza. Vaccination against influenza began in the 1930s, with large-scale availability in the United States beginning in 1945. Both the World Health Organization and the US Centers for Disease Control and Prevention (CDC) recommend yearly vaccination for nearly all people over the age of six months, especially those at high risk, and the influenza vaccine is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. The European Centre for Disease Prevention and Control (ECDC) also recommends yearly vaccination of high-risk groups, particularly pregnant women, the elderly, children between six months and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring-vaccination
Ring vaccination is a strategy to inhibit the spread of a disease by vaccinating those who are most likely to be infected. This strategy vaccinates the contacts of confirmed patients, and people who are in close contact with those contacts. This way, everyone who has been, or could have been, exposed to a patient receives the vaccine, creating a 'ring' of protection that can limit the spread of a pathogen. Ring vaccination requires thorough and rapid surveillance and epidemiologic case investigation. The Intensified Smallpox Eradication Program used this strategy with great success in its efforts to eradicate smallpox in the latter half of the 20th century. Medical use When someone falls ill, people they might have infected should be vaccinated. Contacts who might have been infected typically include family, neighbours, and friends. Several layers of contacts may be vaccinated (the contacts, the contacts' contacts, the contact's contacts' contacts, etc.). Ring vaccination rel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterogeneity
Homogeneity and heterogeneity are concepts relating to the uniformity of a substance, process or image. A homogeneous feature is uniform in composition or character (i.e., color, shape, size, weight, height, distribution, texture, language, income, disease, temperature, radioactivity, architectural design, etc.); one that is heterogeneous is distinctly nonuniform in at least one of these qualities. Etymology and spelling The words ''homogeneous'' and ''heterogeneous'' come from Medieval Latin ''homogeneus'' and ''heterogeneus'', from Ancient Greek ὁμογενής (''homogenēs'') and ἑτερογενής (''heterogenēs''), from ὁμός (''homos'', "same") and ἕτερος (''heteros'', "other, another, different") respectively, followed by γένος (''genos'', "kind"); -ous is an adjectival suffix. Alternate spellings omitting the last ''-e-'' (and the associated pronunciations) are common, but mistaken: ''homogenous'' is strictly a biological/pathological term whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
