title: Determinant

text: The order formula_208 reached by decomposition methods has been improved by different methods. If two matrices of order formula_44 can be multiplied in time formula_314, where formula_315 for some formula_316, then there is an algorithm computing the determinant in time formula_317. This means, for example, that an formula_318 algorithm for computing the determinant exists based on the Coppersmith–Winograd algorithm. This exponent has been further lowered, as of 2016, to 2.373.


title: Determinant

text: Especially for applications concerning matrices over rings, algorithms that compute the determinant without any divisions exist. (By contrast, Gauss elimination requires divisions.) One such algorithm, having complexity formula_319 is based on the following idea: one replaces permutations (as in the Leibniz rule) by so-called closed ordered walks, in which several items can be repeated. The resulting sum has more terms than in the Leibniz rule, but in the process several of these products can be reused, making it more efficient than naively computing with the Leibniz rule. Algorithms can also be assessed according to their bit complexity, i.e., how many bits of accuracy are needed to store intermediate values occurring in the computation. For example, the Gaussian elimination (or LU decomposition) method is of order formula_208, but the bit length of intermediate values can become exponentially long. By comparison, the Bareiss Algorithm, is an exact-division method (so it does use division, but only in cases where these divisions can be performed without remainder) is of the same order, but the bit complexity is roughly the bit size of the original entries in the matrix times formula_44.


title: Determinant

text: If the determinant of "A" and the inverse of "A" have already been computed, the matrix determinant lemma allows rapid calculation of the determinant of , where "u" and "v" are column vectors.


title: Determinant

text: Charles Dodgson (i.e. Lewis Carroll of "Alice's Adventures in Wonderland" fame) invented a method for computing determinants called Dodgson condensation. Unfortunately this interesting method does not always work in its original form.


title: Vaccine

text: A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. A vaccine typically contains an agent that resembles a disease-causing microorganism and is often made from weakened or killed forms of the microbe, its toxins, or one of its surface proteins. The agent stimulates the body's immune system to recognize the agent as a threat, destroy it, and to further recognize and destroy any of the microorganisms associated with that agent that it may encounter in the future.


title: Vaccine

text: Vaccines can be prophylactic (to prevent or ameliorate the effects of a future infection by a natural or "wild" pathogen), or therapeutic (to fight a disease that has already occurred, such as cancer). Some vaccines offer full sterilizing immunity, in which infection is prevented completely.


title: Vaccine

text: The administration of vaccines is called vaccination. Vaccination is the most effective method of preventing infectious diseases; widespread immunity due to vaccination is largely responsible for the worldwide eradication of smallpox and the restriction of diseases such as polio, measles, and tetanus from much of the world. The World Health Organization (WHO) reports that licensed vaccines are currently available for twenty-five different preventable infections.


title: Vaccine

text: The folk practice of inoculation against smallpox was brought from Turkey to Britain in 1721 by Lady Mary Wortley Montagu.


title: Vaccine

text: The terms "vaccine" and "vaccination" are derived from "Variolae vaccinae" (smallpox of the cow), the term devised by Edward Jenner (who both developed the concept of vaccines and created the first vaccine) to denote cowpox. He used the phrase in 1798 for the long title of his "Inquiry into the Variolae vaccinae Known as the Cow Pox", in which he described the protective effect of cowpox against smallpox. In 1881, to honor Jenner, Louis Pasteur proposed that the terms should be extended to cover the new protective inoculations then being developed. The science of vaccine development and production is termed "vaccinology".


title: Vaccine

text: There is overwhelming scientific consensus that vaccines are a very safe and effective way to fight and eradicate infectious diseases. The immune system recognizes vaccine agents as foreign, destroys them, and "remembers" them. When the virulent version of an agent is encountered, the body recognizes the protein coat on the virus, and thus is prepared to respond, by first neutralizing the target agent before it can enter cells, and secondly by recognizing and destroying infected cells before that agent can multiply to vast numbers.


title: Vaccine

text: Limitations to their effectiveness, nevertheless, exist. Sometimes, protection fails for vaccine-related reasons such as failures in vaccine attenuation, vaccination regimens or administration.


title: Vaccine

text: Failure may also occur for host-related reasons if the host's immune system does not respond adequately or at all. Host-related lack of response occurs in an estimated 2-10% of individuals, due to factors including genetics, immune status, age, health and nutritional status. One type of primary immunodeficiency disorder resulting in genetic failure is X-linked agammaglobulinemia, in which the absence of an enzyme essential for B cell development prevents the host's immune system from generating antibodies to a pathogen.


title: Vaccine

text: Host–pathogen interactions and responses to infection are dynamic processes involving multiple pathways in the immune system. A host does not develop antibodies instantaneously: while the body's innate immunity may be activated in as little as twelve hours, adaptive immunity can take 1–2 weeks to fully develop. During that time, the host can still become infected.


title: Vaccine

text: Once antibodies are produced, they may promote immunity in any of several ways, depending on the class of antibodies involved. Their success in clearing or inactivating a pathogen will depend on the amount of antibodies produced and on the extent to which those antibodies are effective at countering the strain of the pathogen involved, since different strains may be differently susceptible to a given immune reaction.


title: Vaccine

text: In some cases vaccines may result in partial immune protection (in which immunity is less than 100% effective but still reduces risk of infection) or in temporary immune protection (in which immunity wanes over time) rather than full or permanent immunity. They can still raise the reinfection threshold for the population as a whole and make a substantial impact. They can also mitigate the severity of infection, resulting in a lower mortality rate, lower morbidity, faster recovery from illness, and a wide range of other effects.


title: Vaccine

text: Those who are older often display less of a response than those who are younger, a pattern known as Immunosenescence.


title: Vaccine

text: Adjuvants commonly are used to boost immune response, particularly for older people whose immune response to a simple vaccine may have weakened.


title: Vaccine

text: If a vaccinated individual does develop the disease vaccinated against (breakthrough infection), the disease is likely to be less virulent than in unvaccinated cases.


title: Vaccine

text: In 1958, there were 763,094 cases of measles in the United States; 552 deaths resulted. After the introduction of new vaccines, the number of cases dropped to fewer than 150 per year (median of 56). In early 2008, there were 64 suspected cases of measles. Fifty-four of those infections were associated with importation from another country, although only thirteen percent were actually acquired outside the United States; 63 of the 64 individuals either had never been vaccinated against measles or were uncertain whether they had been vaccinated.


title: Vaccine

text: Vaccines led to the eradication of smallpox, one of the most contagious and deadly diseases in humans. Other diseases such as rubella, polio, measles, mumps, chickenpox, and typhoid are nowhere near as common as they were a hundred years ago thanks to widespread vaccination programs. As long as the vast majority of people are vaccinated, it is much more difficult for an outbreak of disease to occur, let alone spread. This effect is called herd immunity. Polio, which is transmitted only among humans, is targeted by an extensive eradication campaign that has seen endemic polio restricted to only parts of three countries (Afghanistan, Nigeria, and Pakistan). However, the difficulty of reaching all children, cultural misunderstandings, and disinformation have caused the anticipated eradication date to be missed several times.


title: Vaccine

text: Vaccines also help prevent the development of antibiotic resistance. For example, by greatly reducing the incidence of pneumonia caused by "Streptococcus pneumoniae", vaccine programs have greatly reduced the prevalence of infections resistant to penicillin or other first-line antibiotics.


title: Vaccine

text: Vaccinations given to children, adolescents, or adults are generally safe. Adverse effects, if any, are generally mild. The rate of side effects depends on the vaccine in question. Some common side effects include fever, pain around the injection site, and muscle aches. Additionally, some individuals may be allergic to ingredients in the vaccine. MMR vaccine is rarely associated with febrile seizures.


title: Vaccine

text: Host-("vaccinee")-related determinants that render a person susceptible to infection, such as genetics, health status (underlying disease, nutrition, pregnancy, sensitivities or allergies), immune competence, age, and economic impact or cultural environment can be primary or secondary factors affecting the severity of infection and response to a vaccine. Elderly (above age 60), allergen-hypersensitive, and obese people have susceptibility to compromised immunogenicity, which prevents or inhibits vaccine effectiveness, possibly requiring separate vaccine technologies for these specific populations or repetitive booster vaccinations to limit virus transmission.


title: Vaccine

text: Severe side effects are extremely rare. Varicella vaccine is rarely associated with complications in immunodeficient individuals, and rotavirus vaccines are moderately associated with intussusception.


title: Vaccine

text: At least 19 countries have no-fault compensation programs to provide compensation for those with severe adverse effects of vaccination. The United States' program is known as the National Childhood Vaccine Injury Act, and the United Kingdom employs the Vaccine Damage Payment.


title: Vaccine

text: Vaccines typically contain attenuated, inactivated or dead organisms or purified products derived from them. There are several types of vaccines in use. These represent different strategies used to try to reduce the risk of illness while retaining the ability to induce a beneficial immune response.


title: Vaccine

text: Some vaccines contain live, attenuated microorganisms. Many of these are active viruses that have been cultivated under conditions that disable their virulent properties, or that use closely related but less dangerous organisms to produce a broad immune response. Although most attenuated vaccines are viral, some are bacterial in nature. Examples include the viral diseases yellow fever, measles, mumps, and rubella, and the bacterial disease typhoid. The live "Mycobacterium tuberculosis" vaccine developed by Calmette and Guérin is not made of a contagious strain but contains a virulently modified strain called "BCG" used to elicit an immune response to the vaccine. The live attenuated vaccine containing strain "Yersinia pestis" EV is used for plague immunization. Attenuated vaccines have some advantages and disadvantages. Attenuated, or live, weakened, vaccines typically provoke more durable immunological responses. But they may not be safe for use in immunocompromised individuals, and on rare occasions mutate to a virulent form and cause disease.


title: Vaccine

text: Some vaccines contain inactivated, but previously virulent, micro-organisms that have been destroyed with chemicals, heat, or radiation"ghosts", with intact but empty bacterial cell envelopes. They are considered an intermediate phase between the inactivated and attenuated vaccines. Examples include IPV (polio vaccine), hepatitis A vaccine, rabies vaccine and most influenza vaccines.


title: Vaccine

text: Toxoid vaccines are made from inactivated toxic compounds that cause illness rather than the micro-organism. Examples of toxoid-based vaccines include tetanus and diphtheria. Not all toxoids are for micro-organisms; for example, "Crotalus atrox" toxoid is used to vaccinate dogs against rattlesnake bites.


title: Vaccine

text: Rather than introducing an inactivated or attenuated micro-organism to an immune system (which would constitute a "whole-agent" vaccine), a subunit vaccine uses a fragment of it to create an immune response. One example is the subunit vaccine against hepatitisB, which is composed of only the surface proteins of the virus (previously extracted from the blood serum of chronically infected patients but now produced by recombination of the viral genes into yeast). Another example is edible algae vaccines, such as the virus-like particle (VLP) vaccine against human papillomavirus (HPV), which is composed of the viral major capsid protein. Another example is the hemagglutinin and neuraminidase subunits of the influenza virus. A subunit vaccine is being used for plague immunization.


title: Vaccine

text: Certain bacteria have a polysaccharide outer coat that is poorly immunogenic. By linking these outer coats to proteins (e.g., toxins), the immune system can be led to recognize the polysaccharide as if it were a protein antigen. This approach is used in the "Haemophilus influenzae" type B vaccine.


title: Vaccine

text: Outer membrane vesicles (OMVs) are naturally immunogenic and can be manipulated to produce potent vaccines. The best known OMV vaccines are those developed for serotype B meningococcal disease.


title: Vaccine

text: Heterologous vaccines also known as "Jennerian vaccines", are vaccines that are pathogens of other animals that either do not cause disease or cause mild disease in the organism being treated. The classic example is Jenner's use of cowpox to protect against smallpox. A current example is the use of BCG vaccine made from "Mycobacterium bovis" to protect against tuberculosis.


title: Vaccine

text: Viral vector vaccines use a safe virus to insert pathogen genes in the body to produce specific antigens, such as surface proteins, to stimulate an immune response.


title: Vaccine

text: An mRNA vaccine (or RNA vaccine) is a novel type of vaccine which is composed of the nucleic acid RNA, packaged within a vector such as lipid nanoparticles. Among the COVID-19 vaccines are a number of RNA vaccines under development to combat the COVID-19 pandemic and some have been approved or have received emergency use authorization in some countries. For example, the Pfizer-BioNTech vaccine and Moderna mRNA vaccine are approved for use in adults (with Pfizer vaccine also fully approved for teens aged 16 to 17) in the US.


title: Vaccine

text: DNA vaccination – The proposed mechanism is the insertion and expression of viral or bacterial DNA in human or animal cells (enhanced by the use of electroporation), triggering immune system recognition. Some cells of the immune system that recognize the proteins expressed will mount an attack against these proteins and cells expressing them. Because these cells live for a very long time, if the pathogen that normally expresses these proteins is encountered at a later time, they will be attacked instantly by the immune system. One potential advantage of DNA vaccines is that they are very easy to produce and store.


title: Vaccine

text: In August 2021, Indian authorities gave emergency approval to ZyCoV-D. Developed by Cadila Healthcare, it is the first DNA vaccine approved for humans.


title: Vaccine

text: While most vaccines are created using inactivated or attenuated compounds from micro-organisms, synthetic vaccines are composed mainly or wholly of synthetic peptides, carbohydrates, or antigens.


title: Vaccine

text: Vaccines may be "monovalent" (also called "univalent") or "multivalent" (also called "polyvalent"). A monovalent vaccine is designed to immunize against a single antigen or single microorganism. A multivalent or polyvalent vaccine is designed to immunize against two or more strains of the same microorganism, or against two or more microorganisms. The valency of a multivalent vaccine may be denoted with a Greek or Latin prefix (e.g., "bivalent", "trivalent", or "tetravalent/quadrivalent"). In certain cases, a monovalent vaccine may be preferable for rapidly developing a strong immune response.


title: Vaccine

text: When two or more vaccines are mixed in the same formulation, the two vaccines can interfere. This most frequently occurs with live attenuated vaccines, where one of the vaccine components is more robust than the others and suppresses the growth and immune response to the other components. This phenomenon was first noted in the trivalent Sabin polio vaccine, where the amount of serotype2 virus in the vaccine had to be reduced to stop it from interfering with the "take" of the serotype1 and3 viruses in the vaccine. This phenomenon has also been found to be a problem with the dengue vaccines currently being researched, where the DEN-3 serotype was found to predominate and suppress the response to DEN-1, -2 and -4 serotypes.


title: Vaccine

text: Vaccines typically contain one or more adjuvants, used to boost the immune response. Tetanus toxoid, for instance, is usually adsorbed onto alum. This presents the antigen in such a way as to produce a greater action than the simple aqueous tetanus toxoid. People who have an adverse reaction to adsorbed tetanus toxoid may be given the simple vaccine when the time comes for a booster.


title: Vaccine

text: In the preparation for the 1990 Persian Gulf campaign, the whole cell pertussis vaccine was used as an adjuvant for anthrax vaccine. This produces a more rapid immune response than giving only the anthrax vaccine, which is of some benefit if exposure might be imminent.


title: Vaccine

text: Vaccines may also contain preservatives to prevent contamination with bacteria or fungi. Until recent years, the preservative thiomersal ( "Thimerosal" in the US and Japan) was used in many vaccines that did not contain live viruses. As of 2005, the only childhood vaccine in the U.S. that contains thiomersal in greater than trace amounts is the influenza vaccine, which is currently recommended only for children with certain risk factors. Single-dose influenza vaccines supplied in the UK do not list thiomersal in the ingredients. Preservatives may be used at various stages of the production of vaccines, and the most sophisticated methods of measurement might detect traces of them in the finished product, as they may in the environment and population as a whole.


title: Vaccine

text: Many vaccines need preservatives to prevent serious adverse effects such as "Staphylococcus" infection, which in one 1928 incident killed 12 of 21 children inoculated with a diphtheria vaccine that lacked a preservative. Several preservatives are available, including thiomersal, phenoxyethanol, and formaldehyde. Thiomersal is more effective against bacteria, has a better shelf-life, and improves vaccine stability, potency, and safety; but, in the U.S., the European Union, and a few other affluent countries, it is no longer used as a preservative in childhood vaccines, as a precautionary measure due to its mercury content. Although controversial claims have been made that thiomersal contributes to autism, no convincing scientific evidence supports these claims. Furthermore, a 10–11-year study of 657,461 children found that the MMR vaccine does not cause autism and actually reduced the risk of autism by seven percent.


title: Vaccine

text: Beside the active vaccine itself, the following excipients and residual manufacturing compounds are present or may be present in vaccine preparations:


title: Vaccine

text: Various fairly standardized abbreviations for vaccine names have developed, although the standardization is by no means centralized or global. For example, the vaccine names used in the United States have well-established abbreviations that are also widely known and used elsewhere. An extensive list of them provided in a sortable table and freely accessible is available at a US Centers for Disease Control and Prevention web page. The page explains that "The abbreviations [in] this table (Column 3) were standardized jointly by staff of the Centers for Disease Control and Prevention, ACIP Work Groups, the editor of the "Morbidity and Mortality Weekly Report" (MMWR), the editor of "Epidemiology and Prevention of Vaccine-Preventable Diseases" (the Pink Book), ACIP members, and liaison organizations to the ACIP."


title: Vaccine

text: Some examples are "DTaP" for diphtheria and tetanus toxoids and acellular pertussis vaccine, "DT" for diphtheria and tetanus toxoids, and "Td" for tetanus and diphtheria toxoids. At its page on tetanus vaccination, the CDC further explains that "Upper-case letters in these abbreviations denote full-strength doses of diphtheria (D) and tetanus (T) toxoids and pertussis (P) vaccine. Lower-case "d" and "p" denote reduced doses of diphtheria and pertussis used in the adolescent/adult-formulations. The 'a' in DTaP and Tdap stands for 'acellular', meaning that the pertussis component contains only a part of the pertussis organism."


title: Vaccine

text: Another list of established vaccine abbreviations is at the CDC's page called "Vaccine Acronyms and Abbreviations", with abbreviations used on U.S. immunization records. The United States Adopted Name system has some conventions for the word order of vaccine names, placing head nouns first and adjectives postpositively. This is why the USAN for "OPV" is "poliovirus vaccine live oral" rather than "oral poliovirus vaccine".


title: Vaccine

text: A vaccine "licensure" occurs after the successful conclusion of the development cycle and further the clinical trials and other programs involved through PhasesI–III demonstrating safety, immunoactivity, immunogenetic safety at a given specific dose, proven effectiveness in preventing infection for target populations, and enduring preventive effect (time endurance or need for revaccination must be estimated). Because preventive vaccines are predominantly evaluated in healthy population cohorts and distributed among the general population, a high standard of safety is required. As part of a multinational licensing of a vaccine, the World Health Organization "Expert Committee on Biological Standardization" developed guidelines of international standards for manufacturing and quality control of vaccines, a process intended as a platform for national regulatory agencies to apply for their own licensing process. Vaccine manufacturers do not receive licensing until a complete clinical cycle of development and trials proves the vaccine is safe and has long-term effectiveness, following scientific review by a multinational or national regulatory organization, such as the European Medicines Agency (EMA) or the US Food and Drug Administration (FDA).


title: Vaccine

text: Upon developing countries adopting WHO guidelines for vaccine development and licensure, each country has its own responsibility to issue a national licensure, and to manage, deploy, and monitor the vaccine throughout its use in each nation. Building trust and acceptance of a licensed vaccine among the public is a task of communication by governments and healthcare personnel to ensure a vaccination campaign proceeds smoothly, saves lives, and enables economic recovery. When a vaccine is licensed, it will initially be in limited supply due to variable manufacturing, distribution, and logistical factors, requiring an allocation plan for the limited supply and which population segments should be prioritized to first receive the vaccine.


title: Vaccine

text: Vaccines developed for multinational distribution via the United Nations Children's Fund (UNICEF) require pre-qualification by the WHO to ensure international standards of quality, safety, immunogenicity, and efficacy for adoption by numerous countries.


title: Vaccine

text: The process requires manufacturing consistency at WHO-contracted laboratories following Good Manufacturing Practice (GMP). When UN agencies are involved in vaccine licensure, individual nations collaborate by 1) issuing marketing authorization and a national license for the vaccine, its manufacturers, and distribution partners; and 2) conducting postmarketing surveillance, including records for adverse events after the vaccination program. The WHO works with national agencies to monitor inspections of manufacturing facilities and distributors for compliance with GMP and regulatory oversight.


title: Vaccine

text: Some countries choose to buy vaccines licensed by reputable national organizations, such as EMA, FDA, or national agencies in other affluent countries, but such purchases typically are more expensive and may not have distribution resources suitable to local conditions in developing countries.


title: Vaccine

text: In the European Union (EU), vaccines for pandemic pathogens, such as seasonal influenza, are licensed EU-wide where all the member states comply ("centralized"), are licensed for only some member states ("decentralized"), or are licensed on an individual national level. Generally, all EU states follow regulatory guidance and clinical programs defined by the European Committee for Medicinal Products for Human Use (CHMP), a scientific panel of the European Medicines Agency (EMA) responsible for vaccine licensure. The CHMP is supported by several expert groups who assess and monitor the progress of a vaccine before and after licensure and distribution.


title: Vaccine

text: Under the FDA, the process of establishing evidence for vaccine clinical safety and efficacy is the same as for the approval process for prescription drugs. If successful through the stages of clinical development, the vaccine licensing process is followed by a Biologics License Application which must provide a scientific review team (from diverse disciplines, such as physicians, statisticians, microbiologists, chemists) and comprehensive documentation for the vaccine candidate having efficacy and safety throughout its development. Also during this stage, the proposed manufacturing facility is examined by expert reviewers for GMP compliance, and the label must have a compliant description to enable health care providers' definition of vaccine-specific use, including its possible risks, to communicate and deliver the vaccine to the public. After licensure, monitoring of the vaccine and its production, including periodic inspections for GMP compliance, continue as long as the manufacturer retains its license, which may include additional submissions to the FDA of tests for potency, safety, and purity for each vaccine manufacturing step.


title: Vaccine

text: Drugs Controller General of India is the head of department of the Central Drugs Standard Control Organization of the Government of India responsible for approval of licences of specified categories of drugs such as vaccines AND others like blood and blood products, IV fluids, and sera in India.


title: Vaccine

text: Until a vaccine is in use for the general population, all potential adverse events from the vaccine may not be known, requiring manufacturers to conduct PhaseIV studies for postmarketing surveillance of the vaccine while it is used widely in the public. The WHO works with UN member states to implement post-licensing surveillance. The FDA relies on a Vaccine Adverse Event Reporting System to monitor safety concerns about a vaccine throughout its use in the American public.


title: Vaccine

text: In order to provide the best protection, children are recommended to receive vaccinations as soon as their immune systems are sufficiently developed to respond to particular vaccines, with additional "booster" shots often required to achieve "full immunity". This has led to the development of complex vaccination schedules. Global recommendations of vaccination schedule are issued by Strategic Advisory Group of Experts and will be further translated by advisory committee at the country level with considering of local factors such as disease epidemiology, acceptability of vaccination, equity in local populations, and programmatic and financial constraint. In the United States, the Advisory Committee on Immunization Practices, which recommends schedule additions for the Centers for Disease Control and Prevention, recommends routine vaccination of children against hepatitis A, hepatitis B, polio, mumps, measles, rubella, diphtheria, pertussis, tetanus, HiB, chickenpox, rotavirus, influenza, meningococcal disease and pneumonia.


title: Vaccine

text: The large number of vaccines and boosters recommended (up to 24 injections by age two) has led to problems with achieving full compliance. To combat declining compliance rates, various notification systems have been instituted and many combination injections are now marketed (e.g., Pentavalent vaccine and MMRV vaccine), which protect against multiple diseases.


title: Vaccine

text: Besides recommendations for infant vaccinations and boosters, many specific vaccines are recommended for other ages or for repeated injections throughout lifemost commonly for measles, tetanus, influenza, and pneumonia. Pregnant women are often screened for continued resistance to rubella. The human papillomavirus vaccine is recommended in the U.S. (as of 2011) and UK (as of 2009). Vaccine recommendations for the elderly concentrate on pneumonia and influenza, which are more deadly to that group. In 2006, a vaccine was introduced against shingles, a disease caused by the chickenpox virus, which usually affects the elderly.


title: Vaccine

text: Scheduling and dosing of a vaccination may be tailored to the level of immunocompetence of an individual and to optimize population-wide deployment of a vaccine when it supply is limited, e.g. in the setting of a pandemic.


title: Vaccine

text: One challenge in vaccine development is economic: Many of the diseases most demanding a vaccine, including HIV, malaria and tuberculosis, exist principally in poor countries. Pharmaceutical firms and biotechnology companies have little incentive to develop vaccines for these diseases because there is little revenue potential. Even in more affluent countries, financial returns are usually minimal and the financial and other risks are great.


title: Vaccine

text: Most vaccine development to date has relied on "push" funding by government, universities and non-profit organizations. Many vaccines have been highly cost effective and beneficial for public health. The number of vaccines actually administered has risen dramatically in recent decades. This increase, particularly in the number of different vaccines administered to children before entry into schools may be due to government mandates and support, rather than economic incentive.


title: Vaccine

text: According to the World Health Organization, the biggest barrier to vaccine production in less developed countries has not been patents, but the substantial financial, infrastructure, and workforce requirements needed for market entry. Vaccines are complex mixtures of biological compounds, and unlike the case for prescription drugs, there are no true generic vaccines. The vaccine produced by a new facility must undergo complete clinical testing for safety and efficacy by the manufacturer. For most vaccines, specific processes in technology are patented. These can be circumvented by alternative manufacturing methods, but this required R&D infrastructure and a suitably skilled workforce. In the case of a few relatively new vaccines, such as the human papillomavirus vaccine, the patents may impose an additional barrier.


title: Vaccine

text: When increased production of vaccines was urgently needed during the COVID-19 pandemic in 2021, the World Trade Organization and governments around the world evaluated whether to waive intellectual property rights and patents on COVID-19 vaccines, which would "eliminate all potential barriers to the timely access of affordable COVID-19 medical products, including vaccines and medicines, and scale up the manufacturing and supply of essential medical products."


title: Vaccine

text: Vaccine production is fundamentally different from other kinds of manufacturingincluding regular pharmaceutical manufacturingin that vaccines are intended to be administered to millions of people of whom the vast majority are perfectly healthy. This fact drives an extraordinarily rigorous production process with strict compliance requirements that go far beyond what is required of other products.


title: Vaccine

text: Depending upon the antigen, it can cost anywhere from US$50 to $500 million to build a vaccine production facility, which requires highly specialized equipment, clean rooms, and containment rooms. There is a global scarcity of personnel with the right combination of skills, expertise, knowledge, competence and personality to staff vaccine production lines. With the notable exceptions of Brazil, China, and India, many developing countries' educational systems are unable to provide enough qualified candidates, and vaccine makers based in such countries must hire expatriate personnel to keep production going.


title: Vaccine

text: Vaccine production has several stages. First, the antigen itself is generated. Viruses are grown either on primary cells such as chicken eggs (e.g., for influenza) or on continuous cell lines such as cultured human cells (e.g., for hepatitis A). Bacteria are grown in bioreactors (e.g., "Haemophilus influenzae" type b). Likewise, a recombinant protein derived from the viruses or bacteria can be generated in yeast, bacteria, or cell cultures.


title: Vaccine

text: After the antigen is generated, it is isolated from the cells used to generate it. A virus may need to be inactivated, possibly with no further purification required. Recombinant proteins need many operations involving ultrafiltration and column chromatography. Finally, the vaccine is formulated by adding adjuvant, stabilizers, and preservatives as needed. The adjuvant enhances the immune response to the antigen, stabilizers increase the storage life, and preservatives allow the use of multidose vials. Combination vaccines are harder to develop and produce, because of potential incompatibilities and interactions among the antigens and other ingredients involved.


title: Vaccine

text: The final stage in vaccine manufacture before distribution is fill and finish, which is the process of filling vials with vaccines and packaging them for distribution. Although this is a conceptually simple part of the vaccine manufacture process, it is often a bottleneck in the process of distributing and administering vaccines.


title: Vaccine

text: Vaccine production techniques are evolving. Cultured mammalian cells are expected to become increasingly important, compared to conventional options such as chicken eggs, due to greater productivity and low incidence of problems with contamination. Recombination technology that produces genetically detoxified vaccines is expected to grow in popularity for the production of bacterial vaccines that use toxoids. Combination vaccines are expected to reduce the quantities of antigens they contain, and thereby decrease undesirable interactions, by using pathogen-associated molecular patterns.


title: Vaccine

text: The companies with the highest market share in vaccine production are Merck, Sanofi, GlaxoSmithKline, Pfizer and Novartis, with 70% of vaccine sales concentrated in the EU or US (2013). Vaccine manufacturing plants require large capital investments ($50 million up to $300 million) and may take between 4 and 6 years to construct, with the full process of vaccine development taking between 10 and 15 years. Manufacturing in developing countries is playing an increasing role in supplying these countries, specifically with regards to older vaccines and in Brazil, India and China. The manufacturers in India are the most advanced in the developing world and include the Serum Institute of India, one of the largest producers of vaccines by number of doses and an innovator in processes, recently improving efficiency of producing the measles vaccine by 10 to 20-fold, due to switching to a MRC-5 cell culture instead of chicken eggs. China's manufacturing capabilities are focused on supplying their own domestic need, with Sinopharm (CNPGC) alone providing over 85% of the doses for 14 different vaccines in China. Brazil is approaching the point of supplying its own domestic needs using technology transferred from the developed world.


title: Vaccine

text: The development of new delivery systems raises the hope of vaccines that are safer and more efficient to deliver and administer. Lines of research include liposomes and "ISCOM" (immune stimulating complex).


title: Vaccine

text: Notable developments in vaccine delivery technologies have included oral vaccines. Early attempts to apply oral vaccines showed varying degrees of promise, beginning early in the 20th century, at a time when the very possibility of an effective oral antibacterial vaccine was controversial. By the 1930s there was increasing interest in the prophylactic value of an oral typhoid fever vaccine for example.


title: Vaccine

text: An oral polio vaccine turned out to be effective when vaccinations were administered by volunteer staff without formal training; the results also demonstrated increased ease and efficiency of administering the vaccines. Effective oral vaccines have many advantages; for example, there is no risk of blood contamination. Vaccines intended for oral administration need not be liquid, and as solids, they commonly are more stable and less prone to damage or spoilage by freezing in transport and storage. Such stability reduces the need for a "cold chain": the resources required to keep vaccines within a restricted temperature range from the manufacturing stage to the point of administration, which, in turn, may decrease costs of vaccines.


title: Vaccine

text: A microneedle approach, which is still in stages of development, uses "pointed projections fabricated into arrays that can create vaccine delivery pathways through the skin".


title: Vaccine

text: An experimental needle-free vaccine delivery system is undergoing animal testing. A stamp-size patch similar to an adhesive bandage contains about 20,000 microscopic projections per square cm. This dermal administration potentially increases the effectiveness of vaccination, while requiring less vaccine than injection.


title: Vaccine

text: Vaccinations of animals are used both to prevent their contracting diseases and to prevent transmission of disease to humans. Both animals kept as pets and animals raised as livestock are routinely vaccinated. In some instances, wild populations may be vaccinated. This is sometimes accomplished with vaccine-laced food spread in a disease-prone area and has been used to attempt to control rabies in raccoons.


title: Vaccine

text: Where rabies occurs, rabies vaccination of dogs may be required by law. Other canine vaccines include canine distemper, canine parvovirus, infectious canine hepatitis, adenovirus-2, leptospirosis, "Bordetella", canine parainfluenza virus, and Lyme disease, among others.


title: Vaccine

text: Cases of veterinary vaccines used in humans have been documented, whether intentional or accidental, with some cases of resultant illness, most notably with brucellosis. However, the reporting of such cases is rare and very little has been studied about the safety and results of such practices. With the advent of aerosol vaccination in veterinary clinics, human exposure to pathogens not naturally carried in humans, such as "Bordetella bronchiseptica", has likely increased in recent years. In some cases, most notably rabies, the parallel veterinary vaccine against a pathogen may be as much as orders of magnitude more economical than the human one.


title: Vaccine

text: DIVA (Differentiation of Infected from Vaccinated Animals), also known as SIVA (Segregation of Infected from Vaccinated Animals) vaccines, make it possible to differentiate between infected and vaccinated animals. DIVA vaccines carry at least one epitope less than the equivalent wild microorganism. An accompanying diagnostic test that detects the antibody against that epitope assists in identifying whether the animal has been vaccinated or not.


title: Vaccine

text: The first DIVA vaccines (formerly termed marker vaccines and since 1999 coined as DIVA vaccines) and companion diagnostic tests were developed by J. T. van Oirschot and colleagues at the Central Veterinary Institute in Lelystad, The Netherlands. They found that some existing vaccines against pseudorabies (also termed Aujeszky's disease) had deletions in their viral genome (among which was the gE gene). Monoclonal antibodies were produced against that deletion and selected to develop an ELISA that demonstrated antibodies against gE. In addition, novel genetically engineered gE-negative vaccines were constructed. Along the same lines, DIVA vaccines and companion diagnostic tests against bovine herpesvirus1 infections have been developed.


title: Vaccine

text: The DIVA strategy has been applied in various countries to successfully eradicate pseudorabies virus from those countries. Swine populations were intensively vaccinated and monitored by the companion diagnostic test and, subsequently, the infected pigs were removed from the population. Bovine herpesvirus1 DIVA vaccines are also widely used in practice. Considerable efforts are ongoing to apply the DIVA principle to a wide range of infectious diseases, such as classical swine fever, avian influenza, "Actinobacillus pleuropneumonia" and "Salmonella" infections in pigs.


title: Vaccine

text: Prior to the introduction of vaccination with material from cases of cowpox (heterotypic immunisation), smallpox could be prevented by deliberate variolation with smallpox virus. The earliest hints of the practice of variolation for smallpox in China come during the tenth century. The Chinese also practiced the oldest documented use of variolation, dating back to the fifteenth century. They implemented a method of "nasal insufflation" administered by blowing powdered smallpox material, usually scabs, up the nostrils. Various insufflation techniques have been recorded throughout the sixteenth and seventeenth centuries within China. Two reports on the Chinese practice of inoculation were received by the Royal Society in London in 1700; one by Martin Lister who received a report by an employee of the East India Company stationed in China and another by Clopton Havers.


title: Vaccine

text: Mary Wortley Montagu, who had witnessed variolation in Turkey, had her four-year-old daughter variolated in the presence of physicians of the Royal Court in 1721 upon her return to England. Later on that year, Charles Maitland conducted an experimental variolation of six prisoners in Newgate Prison in London. The experiment was a success, and soon variolation was drawing attention from the royal family, who helped promote the procedure. However, in 1783, several days after Prince Octavius of Great Britain was inoculated, he died. In 1796, the physician Edward Jenner took pus from the hand of a milkmaid with cowpox, scratched it into the arm of an 8-year-old boy, James Phipps, and six weeks later variolated the boy with smallpox, afterwards observing that he did not catch smallpox. Jenner extended his studies and, in 1798, reported that his vaccine was safe in children and adults, and could be transferred from arm-to-arm, which reduced reliance on uncertain supplies from infected cows. In 1804, the Spanish Balmis smallpox vaccination expedition to Spain's colonies Mexico and Philippines used the arm-to-arm transport method to get around the fact the vaccine survived for only 12 days "in vitro". They used cowpox. Since vaccination with cowpox was much safer than smallpox inoculation, the latter, though still widely practiced in England, was banned in 1840.


title: Vaccine

text: Following on from Jenner's work, the second generation of vaccines was introduced in the 1880s by Louis Pasteur who developed vaccines for chicken cholera and anthrax, and from the late nineteenth century vaccines were considered a matter of national prestige. National vaccination policies were adopted and compulsory vaccination laws were passed. In 1931 Alice Miles Woodruff and Ernest Goodpasture documented that the fowlpox virus could be grown in embryonated chicken egg. Soon scientists began cultivating other viruses in eggs. Eggs were used for virus propagation in the development of a yellow fever vaccine in 1935 and an influenza vaccine in 1945. In 1959 growth media and cell culture replaced eggs as the standard method of virus propagation for vaccines.


title: Vaccine

text: Vaccinology flourished in the twentieth century, which saw the introduction of several successful vaccines, including those against diphtheria, measles, mumps, and rubella. Major achievements included the development of the polio vaccine in the 1950s and the eradication of smallpox during the 1960s and 1970s. Maurice Hilleman was the most prolific of the developers of the vaccines in the twentieth century. As vaccines became more common, many people began taking them for granted. However, vaccines remain elusive for many important diseases, including herpes simplex, malaria, gonorrhea, and HIV.


title: Vaccine

text: First generation vaccines are whole-organism vaccineseither live and weakened, or killed forms. Live, attenuated vaccines, such as smallpox and polio vaccines, are able to induce killer T-cell (T or CTL) responses, helper T-cell (T) responses and antibody immunity. However, attenuated forms of a pathogen can convert to a dangerous form and may cause disease in immunocompromised vaccine recipients (such as those with AIDS). While killed vaccines do not have this risk, they cannot generate specific killer T cell responses and may not work at all for some diseases.


title: Vaccine

text: Second generation vaccines were developed to reduce the risks from live vaccines. These are subunit vaccines, consisting of specific protein antigens (such as tetanus or diphtheria toxoid) or recombinant protein components (such as the hepatitis B surface antigen). They can generate T and antibody responses, but not killer T cell responses.


title: Vaccine

text: RNA vaccines and DNA vaccines are examples of third generation vaccines. In 2016 a DNA vaccine for the Zika virus began testing at the National Institutes of Health. Separately, Inovio Pharmaceuticals and GeneOne Life Science began tests of a different DNA vaccine against Zika in Miami. Manufacturing the vaccines in volume was unsolved as of 2016. Clinical trials for DNA vaccines to prevent HIV are underway. mRNA vaccines such as BNT162b2 were developed in the year 2020 with the help of Operation Warp Speed and massively deployed to combat the COVID-19 pandemic. In 2021, Katalin Karikó and Drew Weissman received Columbia University's Horwitz Prize for their pioneering research in mRNA vaccine technology.


title: Vaccine

text: Since at least 2013, scientists have been trying to develop synthetic third-generation vaccines by reconstructing the outside structure of a virus; it was hoped that this will help prevent vaccine resistance.


title: Vaccine

text: Principles that govern the immune response can now be used in tailor-made vaccines against many noninfectious human diseases, such as cancers and autoimmune disorders. For example, the experimental vaccine CYT006-AngQb has been investigated as a possible treatment for high blood pressure. Factors that affect the trends of vaccine development include progress in translatory medicine, demographics, regulatory science, political, cultural, and social responses.


title: Vaccine

text: The idea of vaccine production via transgenic plants was identified as early as 2003. Plants such as tobacco, potato, tomato, and banana can have genes inserted that cause them to produce vaccines usable for humans. In 2005, bananas were developed that produce a human vaccine against hepatitis B.


title: Vaccine

text: Vaccine hesitancy is a delay in acceptance, or refusal of vaccines despite the availability of vaccine services. The term covers outright refusals to vaccinate, delaying vaccines, accepting vaccines but remaining uncertain about their use, or using certain vaccines but not others. There is an overwhelming scientific consensus that vaccines are generally safe and effective. Vaccine hesitancy often results in disease outbreaks and deaths from vaccine-preventable diseases. The World Health Organization therefore characterized vaccine hesitancy as one of the top ten global health threats in 2019.


title: IEEE 802.11

text: IEEE 802.11 is part of the IEEE 802 set of local area network (LAN) technical standards, and specifies the set of media access control (MAC) and physical layer (PHY) protocols for implementing wireless local area network (WLAN) computer communication. The standard and amendments provide the basis for wireless network products using the Wi-Fi brand and are the world's most widely used wireless computer networking standards. IEEE 802.11 is used in most home and office networks to allow laptops, printers, smartphones, and other devices to communicate with each other and access the Internet without connecting wires. IEEE 802.11 is also a basis for vehicle-based communication networks IEEE 802.11p.


title: IEEE 802.11

text: The standards are created and maintained by the Institute of Electrical and Electronics Engineers (IEEE) LAN/MAN Standards Committee (IEEE 802). The base version of the standard was released in 1997 and has had subsequent amendments. While each amendment is officially revoked when it is incorporated in the latest version of the standard, the corporate world tends to market to the revisions because they concisely denote the capabilities of their products. As a result, in the marketplace, each revision tends to become its own standard.


title: IEEE 802.11

text: IEEE 802.11 uses various frequencies including, but not limited to, 2.4 GHz, 5 GHz, 6 GHz, and 60 GHz frequency bands. Although IEEE 802.11 specifications list channels that might be used, the radio frequency spectrum availability allowed varies significantly by regulatory domain.


title: IEEE 802.11

text: The protocols are typically used in conjunction with IEEE 802.2, and are designed to interwork seamlessly with Ethernet, and are very often used to carry Internet Protocol traffic.


title: IEEE 802.11

text: The 802.11 family consists of a series of half-duplex over-the-air modulation techniques that use the same basic protocol. The 802.11 protocol family employs carrier-sense multiple access with collision avoidance (CSMA/CA) whereby equipment listens to a channel for other users (including non 802.11 users) before transmitting each frame (some use the term "packet", which may be ambiguous: "frame" is more technically correct).


title: IEEE 802.11

text: 802.11-1997 was the first wireless networking standard in the family, but 802.11b was the first widely accepted one, followed by 802.11a, 802.11g, 802.11n, and 802.11ac. Other standards in the family (c–f, h, j) are service amendments that are used to extend the current scope of the existing standard, which amendments may also include corrections to a previous specification.


title: IEEE 802.11

text: 802.11b and 802.11g use the 2.4-GHz ISM band, operating in the United States under Part 15 of the U.S. Federal Communications Commission Rules and Regulations. 802.11n can also use that 2.4-GHz band. Because of this choice of frequency band, 802.11b/g/n equipment may occasionally suffer interference in the 2.4-GHz band from microwave ovens, cordless telephones, and Bluetooth devices. 802.11b and 802.11g control their interference and susceptibility to interference by using direct-sequence spread spectrum (DSSS) and orthogonal frequency-division multiplexing (OFDM) signaling methods, respectively.


title: IEEE 802.11

text: 802.11a uses the 5 GHz U-NII band which, for much of the world, offers at least 23 non-overlapping, 20-MHz-wide channels. This is an advantage over the 2.4-GHz, ISM-frequency band, which offers only three non-overlapping, 20-MHz-wide channels where other adjacent channels overlap (see: list of WLAN channels). Better or worse performance with higher or lower frequencies (channels) may be realized, depending on the environment. 802.11n and 802.11ax can use either the 2.4 GHz or 5 GHz band; 802.11ac uses only the 5 GHz band.


title: IEEE 802.11

text: The segment of the radio frequency spectrum used by 802.11 varies between countries. In the US, 802.11a and 802.11g devices may be operated without a license, as allowed in Part 15 of the FCC Rules and Regulations. Frequencies used by channels one through six of 802.11b and 802.11g fall within the 2.4 GHz amateur radio band. Licensed amateur radio operators may operate 802.11b/g devices under Part 97 of the FCC Rules and Regulations, allowing increased power output but not commercial content or encryption.


title: IEEE 802.11

text: In 2018, the Wi-Fi Alliance began using a consumer-friendly generation numbering scheme for the publicly used 802.11 protocols. Wi-Fi generations 1–6 refer to the 802.11b, 802.11a, 802.11g, 802.11n, 802.11ac, and 802.11ax protocols, in that order.


title: IEEE 802.11

text: 802.11 technology has its origins in a 1985 ruling by the U.S. Federal Communications Commission that released the ISM band for unlicensed use.


title: IEEE 802.11

text: In 1991 NCR Corporation/AT&T (now Nokia Labs and LSI Corporation) invented a precursor to 802.11 in Nieuwegein, the Netherlands. The inventors initially intended to use the technology for cashier systems. The first wireless products were brought to the market under the name WaveLAN with raw data rates of 1 Mbit/s and 2 Mbit/s.


title: IEEE 802.11

text: Vic Hayes, who held the chair of IEEE 802.11 for 10 years, and has been called the "father of Wi-Fi", was involved in designing the initial 802.11b and 802.11a standards within the IEEE. He, along with Bell Labs Engineer Bruce Tuch, approached IEEE to create a standard.


title: IEEE 802.11

text: In 1999, the Wi-Fi Alliance was formed as a trade association to hold the Wi-Fi trademark under which most products are sold.


title: IEEE 802.11

text: The major commercial breakthrough came with Apple's adopting Wi-Fi for their iBook series of laptops in 1999. It was the first mass consumer product to offer Wi-Fi network connectivity, which was then branded by Apple as AirPort. One year later IBM followed with its ThinkPad 1300 series in 2000.


title: IEEE 802.11

text: The original version of the standard IEEE 802.11 was released in 1997 and clarified in 1999, but is now obsolete. It specified two net bit rates of 1 or 2 megabits per second (Mbit/s), plus forward error correction code. It specified three alternative physical layer technologies: diffuse infrared operating at 1 Mbit/s; frequency-hopping spread spectrum operating at 1 Mbit/s or 2 Mbit/s; and direct-sequence spread spectrum operating at 1 Mbit/s or 2 Mbit/s. The latter two radio technologies used microwave transmission over the Industrial Scientific Medical frequency band at 2.4 GHz. Some earlier WLAN technologies used lower frequencies, such as the U.S. 900 MHz ISM band.


title: IEEE 802.11

text: Legacy 802.11 with direct-sequence spread spectrum was rapidly supplanted and popularized by 802.11b.


title: IEEE 802.11

text: 802.11a, published in 1999, uses the same data link layer protocol and frame format as the original standard, but an OFDM based air interface (physical layer) was added.


title: IEEE 802.11

text: It operates in the 5 GHz band with a maximum net data rate of 54 Mbit/s, plus error correction code, which yields realistic net achievable throughput in the mid-20 Mbit/s. It has seen widespread worldwide implementation, particularly within the corporate workspace.


title: IEEE 802.11

text: Since the 2.4 GHz band is heavily used to the point of being crowded, using the relatively unused 5 GHz band gives 802.11a a significant advantage. However, this high carrier frequency also brings a disadvantage: the effective overall range of 802.11a is less than that of 802.11b/g. In theory, 802.11a signals are absorbed more readily by walls and other solid objects in their path due to their smaller wavelength, and, as a result, cannot penetrate as far as those of 802.11b. In practice, 802.11b typically has a higher range at low speeds (802.11b will reduce speed to 5.5 Mbit/s or even 1 Mbit/s at low signal strengths). 802.11a also suffers from interference, but locally there may be fewer signals to interfere with, resulting in less interference and better throughput.


title: IEEE 802.11

text: The 802.11b standard has a maximum raw data rate of 11 Mbit/s (Megabits per second) and uses the same media access method defined in the original standard. 802.11b products appeared on the market in early 2000, since 802.11b is a direct extension of the modulation technique defined in the original standard. The dramatic increase in throughput of 802.11b (compared to the original standard) along with simultaneous substantial price reductions led to the rapid acceptance of 802.11b as the definitive wireless LAN technology.


title: IEEE 802.11

text: Devices using 802.11b experience interference from other products operating in the 2.4 GHz band. Devices operating in the 2.4 GHz range include microwave ovens, Bluetooth devices, baby monitors, cordless telephones, and some amateur radio equipment. As unlicensed intentional radiators in this ISM band, they must not interfere with and must tolerate interference from primary or secondary allocations (users) of this band, such as amateur radio.


title: IEEE 802.11

text: In June 2003, a third modulation standard was ratified: 802.11g. This works in the 2.4 GHz band (like 802.11b), but uses the same OFDM based transmission scheme as 802.11a. It operates at a maximum physical layer bit rate of 54 Mbit/s exclusive of forward error correction codes, or about 22 Mbit/s average throughput. 802.11g hardware is fully backward compatible with 802.11b hardware, and therefore is encumbered with legacy issues that reduce throughput by ~21% when compared to 802.11a.


title: IEEE 802.11

text: The then-proposed 802.11g standard was rapidly adopted in the market starting in January 2003, well before ratification, due to the desire for higher data rates as well as reductions in manufacturing costs. By summer 2003, most dual-band 802.11a/b products became dual-band/tri-mode, supporting a and b/g in a single mobile adapter card or access point. Details of making b and g work well together occupied much of the lingering technical process; in an 802.11g network, however, the activity of an 802.11b participant will reduce the data rate of the overall 802.11g network.


title: IEEE 802.11

text: Like 802.11b, 802.11g devices also suffer interference from other products operating in the 2.4 GHz band, for example, wireless keyboards.


title: IEEE 802.11

text: In 2003, task group TGma was authorized to "roll up" many of the amendments to the 1999 version of the 802.11 standard. REVma or 802.11ma, as it was called, created a single document that merged 8 amendments (802.11a, b, d, e, g, h, i, j) with the base standard. Upon approval on 8 March 2007, 802.11REVma was renamed to the then-current base standard IEEE 802.11-2007.


title: IEEE 802.11

text: 802.11n is an amendment that improves upon the previous 802.11 standards; its first draft of certification was published in 2006. The 802.11n standard was retroactively labelled as Wi-Fi 4 by the Wi-Fi Alliance. The standard added support for multiple-input multiple-output antennas (MIMO). 802.11n operates on both the 2.4 GHz and the 5 GHz bands. Support for 5 GHz bands is optional. Its net data rate ranges from 54 Mbit/s to 600 Mbit/s. The IEEE has approved the amendment, and it was published in October 2009. Prior to the final ratification, enterprises were already migrating to 802.11n networks based on the Wi-Fi Alliance's certification of products conforming to a 2007 draft of the 802.11n proposal.


title: IEEE 802.11

text: In May 2007, task group TGmb was authorized to "roll up" many of the amendments to the 2007 version of the 802.11 standard. REVmb or 802.11mb, as it was called, created a single document that merged ten amendments (802.11k, r, y, n, w, p, z, v, u, s) with the 2007 base standard. In addition much cleanup was done, including a reordering of many of the clauses. Upon publication on 29 March 2012, the new standard was referred to as IEEE 802.11-2012.


title: IEEE 802.11

text: IEEE 802.11ac-2013 is an amendment to IEEE 802.11, published in December 2013, that builds on 802.11n. The 802.11ac standard was retroactively labelled as Wi-Fi 5 by the Wi-Fi Alliance. Changes compared to 802.11n include wider channels (80 or 160 MHz versus 40 MHz) in the 5 GHz band, more spatial streams (up to eight versus four), higher-order modulation (up to 256-QAM vs. 64-QAM), and the addition of Multi-user MIMO (MU-MIMO). The Wi-Fi Alliance separated the introduction of ac wireless products into two phases ("waves"), named "Wave 1" and "Wave 2". From mid-2013, the alliance started certifying Wave 1 802.11ac products shipped by manufacturers, based on the IEEE 802.11ac Draft 3.0 (the IEEE standard was not finalized until later that year). In 2016 Wi-Fi Alliance introduced the Wave 2 certification, to provide higher bandwidth and capacity than Wave 1 products. Wave 2 products include additional features like MU-MIMO, 160 MHz channel width support, support for more 5 GHz channels, and four spatial streams (with four antennas; compared to three in Wave 1 and 802.11n, and eight in IEEE's 802.11ax specification).


title: IEEE 802.11

text: IEEE 802.11ad is an amendment that defines a new physical layer for 802.11 networks to operate in the 60 GHz millimeter wave spectrum. This frequency band has significantly different propagation characteristics than the 2.4 GHz and 5 GHz bands where Wi-Fi networks operate. Products implementing the 802.11ad standard are being brought to market under the WiGig brand name. The certification program is now being developed by the Wi-Fi Alliance instead of the now defunct Wireless Gigabit Alliance. The peak transmission rate of 802.11ad is 7 Gbit/s.


title: IEEE 802.11

text: IEEE 802.11ad is a protocol used for very high data rates (about 8 Gbit/s) and for short range communication (about 1–10 meters).


title: IEEE 802.11

text: The WiGig standard is not too well known, although it was announced in 2009 and added to the IEEE 802.11 family in December 2012.


title: IEEE 802.11

text: IEEE 802.11af, also referred to as "White-Fi" and "Super Wi-Fi", is an amendment, approved in February 2014, that allows WLAN operation in TV white space spectrum in the VHF and UHF bands between 54 and 790 MHz. It uses cognitive radio technology to transmit on unused TV channels, with the standard taking measures to limit interference for primary users, such as analog TV, digital TV, and wireless microphones. Access points and stations determine their position using a satellite positioning system such as GPS, and use the Internet to query a geolocation database (GDB) provided by a regional regulatory agency to discover what frequency channels are available for use at a given time and position. The physical layer uses OFDM and is based on 802.11ac. The propagation path loss as well as the attenuation by materials such as brick and concrete is lower in the UHF and VHF bands than in the 2.4 GHz and 5 GHz bands, which increases the possible range. The frequency channels are 6 to 8 MHz wide, depending on the regulatory domain. Up to four channels may be bonded in either one or two contiguous blocks. MIMO operation is possible with up to four streams used for either space–time block code (STBC) or multi-user (MU) operation. The achievable data rate per spatial stream is 26.7 Mbit/s for 6 and 7 MHz channels, and 35.6 Mbit/s for 8 MHz channels. With four spatial streams and four bonded channels, the maximum data rate is 426.7 Mbit/s for 6 and 7 MHz channels and 568.9 Mbit/s for 8 MHz channels.


title: IEEE 802.11

text: IEEE 802.11-2016 which was known as IEEE 802.11 REVmc, is a revision based on IEEE 802.11-2012, incorporating 5 amendments (11ae, 11aa, 11ad, 11ac, 11af). In addition, existing MAC and PHY functions have been enhanced and obsolete features were removed or marked for removal. Some clauses and annexes have been renumbered.


title: IEEE 802.11

text: IEEE 802.11ah, published in 2017, defines a WLAN system operating at sub-1 GHz license-exempt bands. Due to the favorable propagation characteristics of the low frequency spectra, 802.11ah can provide improved transmission range compared with the conventional 802.11 WLANs operating in the 2.4 GHz and 5 GHz bands. 802.11ah can be used for various purposes including large scale sensor networks, extended range hotspot, and outdoor Wi-Fi for cellular traffic offloading, whereas the available bandwidth is relatively narrow. The protocol intends consumption to be competitive with low power Bluetooth, at a much wider range.


title: IEEE 802.11

text: IEEE 802.11ai is an amendment to the 802.11 standard that added new mechanisms for a faster initial link setup time.


title: IEEE 802.11

text: IEEE 802.11aj is a derivative of 802.11ad for use in the 45 GHz unlicensed spectrum available in some regions of the world (specifically China); it also provides additional capabilities for use in the 60 GHz band.


title: IEEE 802.11

text: IEEE 802.11aq is an amendment to the 802.11 standard that will enable pre-association discovery of services. This extends some of the mechanisms in 802.11u that enabled device discovery to discover further the services running on a device, or provided by a network.


title: IEEE 802.11

text: IEEE 802.11-2020, which was known as IEEE 802.11 REVmd, is a revision based on IEEE 802.11-2016 incorporating 5 amendments (11ai, 11ah, 11aj, 11ak, 11aq). In addition, existing MAC and PHY functions have been enhanced and obsolete features were removed or marked for removal. Some clauses and annexes have been added.


title: IEEE 802.11

text: IEEE 802.11ax is the successor to 802.11ac, marketed as (2.4 GHz and 5 GHz) and (6 GHz) by the Wi-Fi Alliance. It is also known as "High Efficiency" , for the overall improvements to clients under "dense environments". For an individual client, the maximum improvement in data rate (PHY speed) against the predecessor (802.11ac) is only 39% (for comparison, this improvement was nearly 500% for the predecessors). Yet, even with this comparatively minor 39% figure, the goal was to provide "4 times" the throughput-per-area of 802.11ac (hence "High Efficiency"). The motivation behind this goal was the deployment of WLAN in dense environments such as corporate offices, shopping malls and dense residential apartments. This is achieved by means of a technique called OFDMA, which is basically multiplexing in the "frequency domain" (as opposed to "spatial" multiplexing, as in 802.11ac). This is equivalent to cellular technology applied into .


title: IEEE 802.11

text: IEEE 802.11ay is a standard that is being developed, also called EDMG: Enhanced Directional MultiGigabit PHY. It is an amendment that defines a new physical layer for 802.11 networks to operate in the 60 GHz millimeter wave spectrum. It will be an extension of the existing 11ad, aimed to extend the throughput, range, and use-cases. The main use-cases include indoor operation and short-range communications due to atmospheric oxygen absorption and inability to penetrate walls. The peak transmission rate of 802.11ay is 40 Gbit/s. The main extensions include: channel bonding (2, 3 and 4), MIMO (up to 4 streams) and higher modulation schemes. The expected range is 300-500 m.


title: IEEE 802.11

text: IEEE 802.11ba Wake-up Radio (WUR) Operation is an amendment to the IEEE 802.11 standard that enables energy efficient operation for data reception without increasing latency. The target active power consumption to receive a WUR packet is less than 1 milliwatt and supports data rates of 62.5 kbit/s and 250 kbit/s. The WUR PHY uses MC-OOK (multicarrier OOK) to achieve extremely low power consumption.


title: IEEE 802.11

text: IEEE 802.11be Extremely High Throughput (EHT) is the potential next amendment to the 802.11 IEEE standard, and will likely be designated as Wi-Fi 7. It will build upon 802.11ax, focusing on WLAN indoor and outdoor operation with stationary and pedestrian speeds in the 2.4 GHz, 5 GHz, and 6 GHz frequency bands.


title: IEEE 802.11

text: Across all variations of 802.11, maximum achievable throughputs are given either based on measurements under ideal conditions or in the layer-2 data rates. However, this does not apply to typical deployments in which data is being transferred between two endpoints, of which at least one is typically connected to a wired infrastructure and the other endpoint is connected to an infrastructure via a wireless link.


title: IEEE 802.11

text: This means that, typically, data frames pass an 802.11 (WLAN) medium and are being converted to 802.3 (Ethernet) or vice versa. Due to the difference in the frame (header) lengths of these two media, the application's packet size determines the speed of the data transfer. This means applications that use small packets (e.g., VoIP) create dataflows with high-overhead traffic (i.e., a low goodput). Other factors that contribute to the overall application data rate are the speed with which the application transmits the packets (i.e., the data rate) and, of course, the energy with which the wireless signal is received. The latter is determined by distance and by the configured output power of the communicating devices.


title: IEEE 802.11

text: The same references apply to the attached graphs that show measurements of UDP throughput. Each represents an average (UDP) throughput (please note that the error bars are there but barely visible due to the small variation) of 25 measurements. Each is with a specific packet size (small or large) and with a specific data rate (10 kbit/s – 100 Mbit/s). Markers for traffic profiles of common applications are included as well. These figures assume there are no packet errors, which, if occurring, will lower the transmission rate further.


title: IEEE 802.11

text: 802.11b, 802.11g, and 802.11n-2.4 utilize the spectrum, one of the ISM bands. 802.11a, 802.11n, and 802.11ac use the more heavily regulated band. These are commonly referred to as the "2.4 GHz and 5 GHz bands" in most sales literature. Each spectrum is sub-divided into "channels" with a center frequency and bandwidth, analogous to how radio and TV broadcast bands are sub-divided.


title: IEEE 802.11

text: The 2.4 GHz band is divided into 14 channels spaced 5 MHz apart, beginning with channel 1, which is centered on 2.412 GHz. The latter channels have additional restrictions or are unavailable for use in some regulatory domains.


title: IEEE 802.11

text: The channel numbering of the spectrum is less intuitive due to the differences in regulations between countries. These are discussed in greater detail on the list of WLAN channels.


title: IEEE 802.11

text: In addition to specifying the channel center frequency, 802.11 also specifies (in Clause 17) a spectral mask defining the permitted power distribution across each channel. The mask requires the signal to be attenuated a minimum of 20 dB from its peak amplitude at ±11 MHz from the center frequency, the point at which a channel is effectively 22 MHz wide. One consequence is that stations can use only every fourth or fifth channel without overlap.


title: IEEE 802.11

text: Availability of channels is regulated by country, constrained in part by how each country allocates radio spectrum to various services. At one extreme, Japan permits the use of all 14 channels for 802.11b, and for 802.11g/n-2.4. Other countries such as Spain initially allowed only channels 10 and 11, and France allowed only 10, 11, 12, and 13; however, Europe now allow channels 1 through 13. North America and some Central and South American countries allow only


title: IEEE 802.11

text: Since the spectral mask defines only power output restrictions up to ±11 MHz from the center frequency to be attenuated by −50 dBr, it is often assumed that the energy of the channel extends no further than these limits. It is more correct to say that the overlapping signal on any channel should be sufficiently attenuated to interfere with a transmitter on any other channel minimally, given the separation between channels. Due to the near–far problem a transmitter can impact (desensitize) a receiver on a "non-overlapping" channel, but only if it is close to the victim receiver (within a meter) or operating above allowed power levels. Conversely, a sufficiently distant transmitter on an overlapping channel can have little to no significant effect.


title: IEEE 802.11

text: Confusion often arises over the amount of channel separation required between transmitting devices. 802.11b was based on direct-sequence spread spectrum (DSSS) modulation and utilized a channel bandwidth of 22 MHz, resulting in "three" "non-overlapping" channels (1, 6, and 11). 802.11g was based on OFDM modulation and utilized a channel bandwidth of 20 MHz. This occasionally leads to the belief that "four" "non-overlapping" channels (1, 5, 9, and 13) exist under 802.11g. However, this is not the case as per 17.4.6.3 Channel Numbering of operating channels of the IEEE Std 802.11 (2012), which states, "In a multiple cell network topology, overlapping and/or adjacent cells using different channels can operate simultaneously without interference if the distance between the center frequencies is at least 25 MHz."


title: IEEE 802.11

text: This does not mean that the technical overlap of the channels recommends the non-use of overlapping channels. The amount of inter-channel interference seen on a configuration using channels 1, 5, 9, and 13 (which is permitted in Europe, but not in North America) is barely different from a three-channel configuration, but with an entire extra channel.


title: IEEE 802.11

text: However, overlap between channels with more narrow spacing (e.g. 1, 4, 7, 11 in North America) may cause unacceptable degradation of signal quality and throughput, particularly when users transmit near the boundaries of AP cells.


title: IEEE 802.11

text: IEEE uses the phrase "regdomain" to refer to a legal regulatory region. Different countries define different levels of allowable transmitter power, time that a channel can be occupied, and different available channels. Domain codes are specified for the United States, Canada, ETSI (Europe), Spain, France, Japan, and China.


title: IEEE 802.11

text: Most Wi-Fi certified devices default to "regdomain" 0, which means least common denominator settings, i.e., the device will not transmit at a power above the allowable power in any nation, nor will it use frequencies that are not permitted in any nation.


title: IEEE 802.11

text: The "regdomain" setting is often made difficult or impossible to change so that the end-users do not conflict with local regulatory agencies such as the United States' Federal Communications Commission.


title: IEEE 802.11

text: The datagrams are called "frames". Current 802.11 standards specify frame types for use in the transmission of data as well as management and control of wireless links.


title: IEEE 802.11

text: Frames are divided into very specific and standardized sections. Each frame consists of a "MAC header", "payload", and "frame check sequence" (FCS). Some frames may not have a payload.


title: IEEE 802.11

text: The first two bytes of the MAC header form a frame control field specifying the form and function of the frame. This frame control field is subdivided into the following sub-fields:


title: IEEE 802.11

text: The next two bytes are reserved for the Duration ID field, indicating how long the field's transmission will take so other devices know when the channel will be available again. This field can take one of three forms: Duration, Contention-Free Period (CFP), and Association ID (AID).


title: IEEE 802.11

text: An 802.11 frame can have up to four address fields. Each field can carry a MAC address. Address 1 is the receiver, Address 2 is the transmitter, Address 3 is used for filtering purposes by the receiver. Address 4 is only present in data frames transmitted between access points in an Extended Service Set or between intermediate nodes in a mesh network.


title: IEEE 802.11

text: The payload or frame body field is variable in size, from 0 to 2304 bytes plus any overhead from security encapsulation, and contains information from higher layers.


title: IEEE 802.11

text: The Frame Check Sequence (FCS) is the last four bytes in the standard 802.11 frame. Often referred to as the Cyclic Redundancy Check (CRC), it allows for integrity checks of retrieved frames. As frames are about to be sent, the FCS is calculated and appended. When a station receives a frame, it can calculate the FCS of the frame and compare it to the one received. If they match, it is assumed that the frame was not distorted during transmission.


title: IEEE 802.11

text: Management frames are not always authenticated, and allow for the maintenance, or discontinuance, of communication. Some common 802.11 subtypes include:


title: IEEE 802.11

text: The body of a management frame consists of frame-subtype-dependent fixed fields followed by a sequence of information elements (IEs).


title: IEEE 802.11

text: Control frames facilitate the exchange of data frames between stations. Some common 802.11 control frames include:


title: IEEE 802.11

text: Data frames carry packets from web pages, files, etc. within the body. The body begins with an IEEE 802.2 header, with the Destination Service Access Point (DSAP) specifying the protocol, followed by a Subnetwork Access Protocol (SNAP) header if the DSAP is hex AA, with the organizationally unique identifier (OUI) and protocol ID (PID) fields specifying the protocol. If the OUI is all zeroes, the protocol ID field is an EtherType value. Almost all 802.11 data frames use 802.2 and SNAP headers, and most use an OUI of 00:00:00 and an EtherType value.


title: IEEE 802.11

text: Similar to TCP congestion control on the internet, frame loss is built into the operation of 802.11. To select the correct transmission speed or Modulation and Coding Scheme, a rate control algorithm may test different speeds. The actual packet loss rate of Access points varies widely for different link conditions. There are variations in the loss rate experienced on production Access points, between 10% and 80%, with 30% being a common average. It is important to be aware that the link layer should recover these lost frames. If the sender does not receive an Acknowledgement (ACK) frame, then it will be resent.


title: IEEE 802.11

text: Within the IEEE 802.11 Working Group, the following IEEE Standards Association Standard and Amendments exist:


title: IEEE 802.11

text: 802.11m is used for standard maintenance. 802.11ma was completed for 802.11-2007, 802.11mb for 802.11-2012, 802.11mc for 802.11-2016, and 802.11md for 802.11-2020.


title: IEEE 802.11

text: Both the terms "standard" and "amendment" are used when referring to the different variants of IEEE standards.


title: IEEE 802.11

text: As far as the IEEE Standards Association is concerned, there is only one current standard; it is denoted by IEEE 802.11 followed by the date published. IEEE 802.11-2020 is the only version currently in publication, superseding previous releases. The standard is updated by means of amendments. Amendments are created by task groups (TG). Both the task group and their finished document are denoted by 802.11 followed by one or two lower case letters, for example, IEEE 802.11a or IEEE 802.11ax. Updating 802.11 is the responsibility of task group m. In order to create a new version, TGm combines the previous version of the standard and all published amendments. TGm also provides clarification and interpretation to industry on published documents. New versions of the IEEE 802.11 were published in 1999, 2007, 2012, 2016, and 2020.


title: IEEE 802.11

text: Various terms in 802.11 are used to specify aspects of wireless local-area networking operation and may be unfamiliar to some readers.


title: IEEE 802.11

text: For example, Time Unit (usually abbreviated TU) is used to indicate a unit of time equal to 1024 microseconds. Numerous time constants are defined in terms of TU (rather than the nearly equal millisecond).


title: IEEE 802.11

text: Also, the term "Portal" is used to describe an entity that is similar to an 802.1H bridge. A Portal provides access to the WLAN by non-802.11 LAN STAs.


title: IEEE 802.11

text: In 2001, a group from the University of California, Berkeley presented a paper describing weaknesses in the 802.11 Wired Equivalent Privacy (WEP) security mechanism defined in the original standard; they were followed by Fluhrer, Mantin, and Shamir's paper titled "Weaknesses in the Key Scheduling Algorithm of RC4". Not long after, Adam Stubblefield and AT&T publicly announced the first verification of the attack. In the attack, they were able to intercept transmissions and gain unauthorized access to wireless networks.


title: IEEE 802.11

text: The IEEE set up a dedicated task group to create a replacement security solution, 802.11i (previously, this work was handled as part of a broader 802.11e effort to enhance the MAC layer). The Wi-Fi Alliance announced an interim specification called Wi-Fi Protected Access (WPA) based on a subset of the then-current IEEE 802.11i draft. These started to appear in products in mid-2003. IEEE 802.11i (also known as WPA2) itself was ratified in June 2004, and uses the Advanced Encryption Standard (AES), instead of RC4, which was used in WEP. The modern recommended encryption for the home/consumer space is WPA2 (AES Pre-Shared Key), and for the enterprise space is WPA2 along with a RADIUS authentication server (or another type of authentication server) and a strong authentication method such as EAP-TLS.


title: IEEE 802.11

text: In January 2005, the IEEE set up yet another task group "w" to protect management and broadcast frames, which previously were sent unsecured. Its standard was published in 2009.


title: IEEE 802.11

text: In December 2011, a security flaw was revealed that affects some wireless routers with a specific implementation of the optional Wi-Fi Protected Setup (WPS) feature. While WPS is not a part of 802.11, the flaw allows an attacker within the range of the wireless router to recover the WPS PIN and, with it, the router's 802.11i password in a few hours.


title: IEEE 802.11

text: In late 2014, Apple announced that its iOS 8 mobile operating system would scramble MAC addresses during the pre-association stage to thwart retail footfall tracking made possible by the regular transmission of uniquely identifiable probe requests.


title: IEEE 802.11

text: Wi-Fi users may be subjected to a Wi-Fi deauthentication attack to eavesdrop, attack passwords, or force the use of another, usually more expensive access point.


title: Sue Bird

text: Suzanne Brigit Bird (born October 16, 1980) is an American former professional basketball player who played her entire career with the Seattle Storm of the Women's National Basketball Association (WNBA) Bird was drafted by the Storm first overall in the 2002 WNBA draft and is considered to be one of the greatest players in WNBA history. As of 2021, Bird is the only WNBA player to win titles in three different decades. She held a front office position for the NBA's Denver Nuggets as their Basketball Operations Associate. She has also played for three teams in Russia. She holds both U.S. and Israeli citizenship.


title: Sue Bird

text: In high school, she was the New York State Player of the Year, the "New York Daily News" Player of the Year, and a WBCA All-American. In her senior year on the undefeated University of Connecticut team in 2002, she won the Wade Trophy and the Naismith Award as College Player of the Year. She finished her UConn career ranked first in three-point field goal percentage and free throw percentage, second in assists and steals, and as a three-time winner of the Nancy Lieberman Award as the top point guard in the nation, while leading her team to a record of 114–4.


title: Sue Bird

text: Bird has won a joint-record four WNBA championships with the Storm (2004, 2010, 2018, 2020), a historic five Olympic gold medals (2004, 2008, 2012, 2016, and 2020), two NCAA Championships with UConn (2000, 2002); and four FIBA World Cups (2002, 2010, 2014, 2018). She is one of only 11 women to attain all four accolades. She is also a five-time EuroLeague Women champion (2007-2010, 2013). During her WNBA career, she has been selected to thirteen WNBA All-Star teams and eight All-WNBA teams. Additionally, she was voted by fans as one of the WNBA's Top 15 Players of All Time in 2011, was voted into the WNBA Top 20@20 as one of the league's top 20 players of all time in 2016, and was voted into The W25 as one of the league's top 25 players of all time in 2021. Her fifth Olympic gold medal, at the 2020 Olympic Games in Tokyo, makes her one of only two Olympic basketball players—of either gender—ever to win five gold medals, with the other player being her US Olympic teammate Diana Taurasi.


title: Sue Bird

text: Bird publicly confirmed on June 16, 2022 that she will retire from playing professional basketball after the 2022 WNBA season.


title: Sue Bird

text: Bird was born in Syosset, Nassau County, New York, on Long Island to Herschel and Nancy Bird. She has one sibling, an older sister named Jen. Her father's ancestry is Russian-Jewish, and their original last name was "Boorda". She is also an Israeli citizen since 2006, on account of her Jewish father and paternal grandparents, but she represents her birth country, the United States, in international competitions.


title: Sue Bird

text: Bird was interested in sports from an early age, which was partly influenced by her athletic older sister. Besides basketball, she played soccer and tennis and ran track. Bird started playing Amateur Athletic Union basketball in the sixth grade. While only 11 years old, she played during halftime of a St. John's basketball game; her play was so impressive that a security guard asked for her autograph.


title: Sue Bird

text: Bird played her freshman and sophomore years at Syosset High School, but wanted more competition. She therefore enrolled at Christ the King Regional High School in Queens, New York. Bird spent two seasons at Christ the King, and the Royals went 24–3 her junior year. In the second season her team finished undefeated and won the New York state championship, and the national title. Bird won many awards, including the New York State Player of the Year, and the "New York Daily News" Player of the Year. Bird was named a WBCA All-American. She participated in the Women's Basketball Coaches Association High School All-America Game, where she scored 11 points.


title: Sue Bird

text: Bird was recruited by a number of teams including Stanford and Vanderbilt. She considered UConn the favorite, but she began to waver when Keirsten Walters and Brianne Stepherson, both point guards, announced commitments to UConn. She worried that there might not be room for her to play. However, when Stepherson changed her mind and committed to Boston College, Bird committed to UConn. In addition to increased opportunity, UConn was close to home and "felt right" to her. Eight games into her freshman season, Bird suffered a torn ACL. Since she had played more than 20% of team's games the 1998–1999 season, she was not able to redshirt. In her sophomore season (1999–2000), she came back to lead the team to a 36–1 record, the Big East Championship, and the 2000 NCAA Division I women's basketball tournament. In her junior season (2000–2001), the Huskies went 32–3, with the final loss coming against UConn's Big East rival Notre Dame in the Final Four. This game would be the last loss in Bird's college career, as the Huskies went 39–0 in 2001–2002, her senior season. In that season, she also won the Wade Trophy, Honda Sports Award and Naismith Award as College Player of the Year.


title: Sue Bird

text: During her junior year, Bird played in a game against Notre Dame referred to as "the best women's basketball game ever played". The game was memorialized in a book, "Bird at the Buzzer", in which Bird took the eponymous shot at the buzzer to win the game.


title: Sue Bird

text: She finished her UConn career on many of the record lists. She currently ranks No. 24 on the 1,000-point list with 1,378 points, No. 2 in assists with 585, and seventh with 243 steals. She ranks number 1 in three-point field goal percentage (45.9) and free throw percentage (89.2). She won two National Championships, three Big East Championships and Big East regular season titles. Bird was the inaugural winner of the Nancy Lieberman Award in 2000, given to the top point guard in the nation, and won the award again in 2001 and 2002. Overall, her record at UConn in games she played is a remarkable 114–4. Bird was a member of the inaugural class (2006) of inductees to the University of Connecticut women's basketball "Huskies of Honor" recognition program.


title: Sue Bird

text: The Seattle Storm selected Bird with the first overall pick of the 2002 WNBA draft. She would play alongside superstar Lauren Jackson who was also drafted first overall the year before. In her rookie season, Bird started all 32 games for the Storm and averaged 14.4 ppg. She was selected as a starter on the 2002 WNBA Western Conference All-Star team. Bird was the runner-up for the Rookie of the Year award, and one of only two rookies to make the All-WNBA First Team. Both Bird and Jackson led the Storm to their first playoff appearance. During her first year in the league, Bird scored a career-high 33 points in a regular-season game against the Portland Fire. Since her rookie season she has continuously been selected to the Western Conference All-Star team.


title: Sue Bird

text: In 2004, the Storm acquired shooting guard Betty Lennox in a dispersal draft, joining forces with Bird and Lauren Jackson, forming a dominant trio of star players to carry the Storm to its first WNBA Championship. By winning the WNBA Championship, Bird became one of 11 women to receive an Olympic gold medal, an NCAA Championship, and a WNBA Championship. The others are Sheryl Swoopes, Cynthia Cooper-Dyke, Tamika Catchings, Brittney Griner and fellow Huskies Swin Cash, Kara Wolters, Diana Taurasi, Maya Moore, Breanna Stewart, and Asjha Jones.


title: Sue Bird

text: En route to the Storm's second championship, Bird had one of the most clutch moments in WNBA Playoff history; during the Conference Finals against the championship-defending Phoenix Mercury with the Storm up 1–0 in the series, Bird hit a game winning three-pointer with two seconds left in Game 2 to put the Storm up 91–88, after erasing a 19-point deficit to advance to the 2010 WNBA Finals. Also in Game 1 of the 2010 WNBA Finals, Bird hit a game winning jump shot with 2 seconds left to put the Storm up 79–77 and would later sweep the series. In 2011, she was voted in by fans as one of the Top 15 players in the 15-year history of the WNBA.


title: Sue Bird

text: During the 2012 WNBA season, Bird had been having problems with her knee. Bird was still able to play 29 games during the regular season and in the playoffs. In the off-season, Bird had knee surgery which would prevent her from playing the entire 2013 season.


title: Sue Bird

text: Bird would come back healthy for the 2014 WNBA season, she played 33 games, averaged 10.6 ppg and 4.6 apg. She was voted as a WNBA all-star that year. However the Storm never made it to the playoffs and would also fail to make the playoffs the following year.


title: Sue Bird

text: In the 2016 season, Bird would have a resurgence, putting up her best numbers since coming back from knee surgery. She averaged 12.8 ppg while shooting a career-high in 3-point field goal percentage and led the league in assists with 5.8 apg. For the fifth time in her career, Bird was named to the All-WNBA First Team for the first time in 12 years. Prior to the season, the Storm selected Breanna Stewart first overall in the 2016 WNBA draft, their second number one overall pick in a row after drafting Jewell Loyd the year before. With the addition of Stewart and Loyd quickly developing into a star player, the Storm made it back to the playoffs for the first time in 3 years with a 16–18 record. With the WNBA's new playoff format in effect, the Storm were the number 7 seed in the league and faced the Atlanta Dream in the first round, losing the single elimination game 94–85. Bird was also listed in the WNBA Top 20@20, a list of the league's best 20 players ever in celebration of the WNBA's twentieth anniversary.


title: Sue Bird

text: In April 2017, it was announced by the Storm that Bird had undergone left knee surgery earlier in the month, which caused her to miss training camp. She was ruled out indefinitely. On May 21, 2017, Bird returned after recovering from knee surgery and made her season debut, making her both the oldest active player and the oldest starter in the WNBA. She scored 9 points along with 10 assists in an 81–71 victory over the Washington Mystics. On June 11, 2017, Bird scored a season-high 21 points along with 10 assists in a 94–86 loss to the New York Liberty. Bird was voted into the 2017 WNBA All-Star Game, making it her 10th all-star game appearance (tying Tamika Catchings for most all-star game appearances). She had set the All-Star Game record for assists with a performance of 8 points along with 11 assists for the Western Conference All-Stars team in a 130–121 victory. On September 1, 2017, Bird became the WNBA all-time leader in assists with a career total of 2,600 assists, passing Ticha Penicheiro in a 110–106 overtime loss to the Washington Mystics. She finished the game with 19 points along with a season-high of 13 assists. Bird would finish off the 2017 season, averaging a career-high in assists per game as the Storm finished 15–19 with the 8th seed in the league. The Storm would lose 79–69 to the Phoenix Mercury in the first round elimination game.


title: Sue Bird

text: On July 8, 2018, Bird scored a season-high 21 points in a 97–91 victory over the Washington Mystics. During that game she became the Storm's all-time leading scorer, passing Lauren Jackson's 6,007 points. On July 19, 2018, Bird was voted into the 2018 WNBA All-Star Game, passing Tamika Catchings for most all-star appearances. On July 22, 2018, Bird broke yet another record, this time for the most WNBA regular-season games played after she passed Delisha Milton-Jones by playing her 500th game against the Atlanta Dream. By the end of the season, Bird finished with a career-high in assists, field goal shooting and a new career-high in three-point shooting percentage as the Storm finished as the number 1 seed in the league with a 26–8 record, receiving a double-bye to the semi-finals and home court advantage throughout the playoffs. In the semi-finals, the Storm defeated the Phoenix Mercury in a hard-fought five-game series. The Storm had a 2–0 lead, lost two in a row and finished off the series with a win in game 5 at home. Bird scored a season-high 22 points in game 5. With that win, the Storm would advance to the WNBA Finals for the first time since 2010. In the Finals, they would sweep the Washington Mystics, winning their first championship in 8 years.


title: Sue Bird

text: During the first week of the 2019 season, Bird was sidelined as she once again underwent left knee surgery and was ruled out indefinitely. By September 2019, it was announced that Bird would not return, causing her to miss the entire season. Without Bird, the Storm were unable to defend their title as they were eliminated in the second round elimination game by the Los Angeles Sparks.


title: Sue Bird

text: In 2020, Bird would be fully healthy and make her return for the Storm. The season was delayed and shortened to 22 games in a bubble at IMG Academy due to the COVID-19 pandemic. She had reaggravated her knee during the season, causing her to miss half of the games, with a fully healthy and active roster, the Storm finished 18–4 with the number 2 seed, receiving a double bye to the semi-finals. In the semi-finals they would sweep the Minnesota Lynx in three games, advancing back to the WNBA Finals for the second time in three years. In the Finals, the Storm would win the championship after defeating the Las Vegas Aces in a three-game sweep, earning Bird her fourth WNBA championship, making her the first player in WNBA history to win a championship in three different decades.


title: Sue Bird

text: In 2021, Bird re-signed with the Storm on a one-year deal, which allowed her to play her 18th season in the league, moving her past Milton-Jones for most seasons played in the WNBA. In a July 2021 game against the Los Angeles Sparks Bird's first three-pointer put her number sixth on the WNBA career scoring list, passing Katie Smith's 6452 points with a total of 6490 points (as of August 2021) and counting. During that season, the WNBA's 25th, she was named to The W25, the league's official list of the 25 greatest players in its history.


title: Sue Bird

text: In the 2004–05 WNBA off-season, she played in Russia, with Storm teammate Kamila Vodichkova on the Dynamo Moscow. In the 2005–06 WNBA off-season, she played on the same team, reaching the Russian championship and the Euroleague women's playoffs.