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59-461: HD-1 is a supersonic land-attack and anti-ship missile developed by Guangdong Hongda Mining Company. Unlike the similar CM-302 , the HD-1 requires an add-on solid rocket booster . Related development Comparable missiles Supersonic Sounds are traveling vibrations in the form of pressure waves in an elastic medium. Objects move at supersonic speed when the objects move faster than

118-625: A healthy diet are also recommended. Supportive care in severe cases includes treatment to relieve symptoms , fluid therapy , oxygen support and prone positioning , and medications or devices to support other affected vital organs. More severe cases may need treatment in hospital. In those with low oxygen levels, use of the glucocorticoid dexamethasone is recommended to reduce mortality. Noninvasive ventilation and, ultimately, admission to an intensive care unit for mechanical ventilation may be required to support breathing. Extracorporeal membrane oxygenation (ECMO) has been used to address

177-627: A variant of concern (VoC) or a variant of interest (VoI). Many of these variants have shared the more infectious D614G . As of May 2023, the WHO had downgraded all variants of concern to previously circulating as these were no longer detected in new infections. Sub-lineages of the Omicron variant (BA.1 – BA.5) were considered separate VoCs by the WHO until they were downgraded in March 2023 as no longer widely circulating. As of 24 September 2024 ,

236-493: A comprehensive international study. Such deaths include deaths due to healthcare capacity constraints and priorities, as well as reluctance to seek care (to avoid possible infection). Further research may help distinguish the proportions directly caused by COVID-19 from those caused by indirect consequences of the pandemic. In May 2022, the WHO estimated the number of excess deaths by the end of 2021 to be 14.9 million compared to 5.4 million reported COVID-19 deaths, with

295-595: A large number of people". During the COVID-19 pandemic, as with other pandemics, the meaning of this term has been challenged. The end of a pandemic or other epidemic only rarely involves the total disappearance of a disease, and historically, much less attention has been given to defining the ends of epidemics than their beginnings. The ends of particular epidemics have been defined in a variety of ways, differing according to academic field, and differently based on location and social group. An epidemic's end can be considered

354-451: A median range of 0.24% to 1.49%. IFRs rise as a function of age (from 0.002% at age 10 and 0.01% at age 25, to 0.4% at age 55, 1.4% at age 65, 4.6% at age 75, and 15% at age 85). These rates vary by a factor of ≈10,000 across the age groups. For comparison, the IFR for middle-aged adults is two orders of magnitude higher than the annualised risk of a fatal automobile accident and much higher than

413-824: A random sample have consistently found that total infections considerably exceed the reported case counts. Many countries, early on, had official policies to not test those with only mild symptoms. The strongest risk factors for severe illness are obesity, complications of diabetes , anxiety disorders, and the total number of conditions. During the start of the COVID-19 pandemic it was not clear whether young people were less likely to be infected, or less likely to develop symptoms and be tested. A retrospective cohort study in China found that children and adults were just as likely to be infected. Among more thorough studies, preliminary results from 9 April 2020 found that in Gangelt ,

472-461: A social phenomenon, not just a biological one. Time reported in March 2024 that expert opinions differ on whether or not COVID-19 is considered endemic or pandemic, and that the WHO continued to call the disease a pandemic on its website. During the initial outbreak in Wuhan , the virus and disease were commonly referred to as "coronavirus", "Wuhan coronavirus", "the coronavirus outbreak" and

531-451: A test. Conversely, deaths of people who died from underlying conditions following a positive test may be included. Countries such as Belgium include deaths from suspected cases, including those without a test, thereby increasing counts. Official death counts have been claimed to underreport the actual death toll, because excess mortality (the number of deaths in a period compared to a long-term average) data show an increase in deaths that

590-419: Is " ultrasonic ", but the older meaning sometimes still lives on, as in the word superheterodyne The tip of a bullwhip is generally seen as the first object designed to reach the speed of sound. This action results in its telltale "crack", which is actually just a sonic boom . The first human-made supersonic boom was likely caused by a piece of common cloth, leading to the whip's eventual development. It's

649-518: Is associated with COVID-19 and is reported in as many as 88% of cases. The disease is mainly transmitted via the respiratory route when people inhale droplets and small airborne particles (that form an aerosol ) that infected people exhale as they breathe, talk, cough, sneeze, or sing. Infected people are more likely to transmit COVID-19 when they are physically close to other non-infected individuals. However, infection can occur over longer distances, particularly indoors. SARS‑CoV‑2 belongs to

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708-428: Is crack formation faster than the speed of sound in a brittle material. The word supersonic comes from two Latin derived words ; 1) super : above and 2) sonus : sound, which together mean above sound, or faster than sound. At the beginning of the 20th century, the term "supersonic" was used as an adjective to describe sound whose frequency is above the range of normal human hearing. The modern term for this meaning

767-611: Is discouraged altogether by the World Health Organization (WHO), due to limited evidence of its efficacy. The severity of COVID-19 varies. It may take a mild course with few or no symptoms, resembling other common upper respiratory diseases such as the common cold . In 3–4% of cases (7.4% for those over age 65) symptoms are severe enough to cause hospitalisation. Mild cases typically recover within two weeks, while those with severe or critical diseases may take three to six weeks to recover. Among those who have died,

826-439: Is intended to provide acquired immunity against severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2), the virus that causes coronavirus disease 2019 ( COVID-19 ). Prior to the COVID-19 pandemic, an established body of knowledge existed about the structure and function of coronaviruses causing diseases like severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). This knowledge accelerated

885-444: Is more complex. The main key to having low supersonic drag is to properly shape the overall aircraft to be long and thin, and close to a "perfect" shape, the von Karman ogive or Sears-Haack body . This has led to almost every supersonic cruising aircraft looking very similar to every other, with a very long and slender fuselage and large delta wings, cf. SR-71 , Concorde , etc. Although not ideal for passenger aircraft, this shaping

944-490: Is not explained by COVID-19 deaths alone. Using such data, estimates of the true number of deaths from COVID-19 worldwide have included a range from 18.2 to 33.5 million (≈27.4 million) by 18 November 2023 by The Economist , as well as over 18.5 million by 1 April 2023 by the Institute for Health Metrics and Evaluation and ≈18.2 million (earlier) deaths between 1 January 2020, and 31 December 2021, by

1003-478: Is quite adaptable for bomber use. COVID-19 pandemic The COVID-19 pandemic (also known as the coronavirus pandemic and COVID pandemic ), caused by severe acute respiratory syndrome coronavirus 2 ( SARS-CoV-2 ), began with an outbreak of COVID-19 in Wuhan , China, in December 2019. It spread to other areas of Asia, and then worldwide in early 2020. The World Health Organization (WHO) declared

1062-452: Is the ratio of deaths to diagnoses. This metric can be misleading because of the delay between symptom onset and death and because testing focuses on symptomatic individuals. Based on Johns Hopkins University statistics, the global CFR was 1.02 percent (6,881,955 deaths for 676,609,955 cases) as of 10 March 2023. The number varies by region and has generally declined over time. Several variants have been named by WHO and labelled as

1121-406: Is the seventh known coronavirus to infect people, after 229E , NL63 , OC43 , HKU1 , MERS-CoV , and the original SARS-CoV . The standard method of testing for presence of SARS-CoV-2 is a nucleic acid test , which detects the presence of viral RNA fragments. As these tests detect RNA but not infectious virus, its "ability to determine duration of infectivity of patients is limited." The test

1180-614: Is typically done on respiratory samples obtained by a nasopharyngeal swab ; however, a nasal swab or sputum sample may also be used. The WHO has published several testing protocols for the disease. Preventive measures to reduce the chances of infection include getting vaccinated, staying at home or spending more time outdoors, avoiding crowded places, keeping distance from others, wearing a mask in public, ventilating indoor spaces, managing potential exposure durations, washing hands with soap and water often and for at least twenty seconds, practising good respiratory hygiene, and avoiding touching

1239-545: The COVID-19 pandemic and the vehicle was put up for sale. Most modern fighter aircraft are supersonic aircraft. No modern-day passenger aircraft are capable of supersonic speed, but there have been supersonic passenger aircraft , namely Concorde and the Tupolev Tu-144 . Both of these passenger aircraft and some modern fighters are also capable of supercruise , a condition of sustained supersonic flight without

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1298-514: The Huanan Seafood Wholesale Market there, but it is possible that human-to-human transmission began earlier. Molecular clock analysis suggests that the first cases were likely to have been between October and November 2019. The scientific consensus is that the virus is most likely of a zoonotic origin, from bats or another closely related mammal. While other explanations such as speculations that SARS-CoV-2

1357-407: The Institute for Health Metrics and Evaluation estimating the true number of cases as of early 2022 to be in the billions. One measure that public health officials and policymakers have used to monitor the pandemic and guide decision-making is the test positivity rate ("percent positive"). According to Johns Hopkins in 2020, one benchmark for a "too high" per cent positive is 5%, which was used by

1416-594: The ThrustSSC . The vehicle, driven by Andy Green , holds the world land speed record, having achieved an average speed on its bi-directional run of 1,228 km/h (763 mph) in the Black Rock Desert on 15 October 1997. The Bloodhound LSR project planned an attempt on the record in 2020 at Hakskeenpan in South Africa with a combination jet and hybrid rocket propelled car. The aim was to break

1475-562: The Tupolev Tu-160 and Rockwell B-1 Lancer are also supersonic-capable. The aerodynamics of supersonic aircraft is simpler than subsonic aerodynamics because the airsheets at different points along the plane often cannot affect each other. Supersonic jets and rocket vehicles require several times greater thrust to push through the extra aerodynamic drag experienced within the transonic region (around Mach 0.85–1.2). At these speeds aerospace engineers can gently guide air around

1534-602: The basic reproduction number (R 0 ) for COVID-19 in January 2020 were between 1.4 and 2.5, but a subsequent analysis claimed that it may be about 5.7 (with a 95 per cent confidence interval of 3.8 to 8.9). In December 2021, the number of cases continued to climb due to several factors, including new COVID-19 variants. As of that 28   December, 282,790,822 individuals worldwide had been confirmed as infected. As of 14 April 2022 , over 500 million cases were confirmed globally. Most cases are unconfirmed, with

1593-524: The fuselage of the aircraft without producing new shock waves , but any change in cross area farther down the vehicle leads to shock waves along the body. Designers use the Supersonic area rule and the Whitcomb area rule to minimize sudden changes in size. However, in practical applications, a supersonic aircraft must operate stably in both subsonic and supersonic profiles, hence aerodynamic design

1652-467: The speed of sound decreases somewhat with altitude, due to lower temperatures found there (typically up to 25 km). At even higher altitudes the temperature starts increasing, with the corresponding increase in the speed of sound. When an inflated balloon is burst, the torn pieces of latex contract at supersonic speed, which contributes to the sharp and loud popping noise. To date, only one land vehicle has officially travelled at supersonic speed,

1711-474: The variants of interest as specified by the World Health Organization are BA.2.86 and JN.1, and the variants under monitoring are JN.1.7, KP.2, KP.3, KP.3.1.1, JN.1.18, LB.1, and XEC. Symptoms of COVID-19 are variable, ranging from mild symptoms to severe illness. Common symptoms include headache, loss of smell and taste , nasal congestion and runny nose , cough, muscle pain , sore throat , fever, diarrhoea , and breathing difficulties . People with

1770-546: The wave motion travelling through the bullwhip that makes it capable of achieving supersonic speeds. Most modern firearm bullets are supersonic, with rifle projectiles often travelling at speeds approaching and in some cases well exceeding Mach 3 . Most spacecraft are supersonic at least during portions of their reentry, though the effects on the spacecraft are reduced by low air densities. During ascent, launch vehicles generally avoid going supersonic below 30 km (~98,400 feet) to reduce air drag. Note that

1829-429: The "Wuhan coronavirus outbreak", with the disease sometimes called "Wuhan pneumonia ". In January 2020, the WHO recommended 2019-nCoV and 2019-nCoV acute respiratory disease as interim names for the virus and disease per 2015 international guidelines against using geographical locations (e.g. Wuhan, China), animal species, or groups of people in disease and virus names in part to prevent social stigma . WHO finalised

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1888-640: The WHO in the past. As of 10 March 2023, more than 6.88   million deaths had been attributed to COVID-19. The first confirmed death was in Wuhan on 9 January 2020. These numbers vary by region and over time, influenced by testing volume, healthcare system quality, treatment options, government response, time since the initial outbreak, and population characteristics, such as age, sex, and overall health. Multiple measures are used to quantify mortality. Official death counts typically include people who died after testing positive. Such counts exclude deaths without

1947-419: The WHO, US, European Union, and Australia. On 12 November 2022, the WHO released its Global Vaccine Market Report. The report indicated that "inequitable distribution is not unique to COVID-19 vaccines"; countries that are not economically strong struggle to obtain vaccines. On 14 November 2022, the first inhalable vaccine was introduced, developed by Chinese biopharmaceutical company CanSino Biologics , in

2006-448: The broad family of viruses known as coronaviruses . It is a positive-sense single-stranded RNA (+ssRNA) virus, with a single linear RNA segment. Coronaviruses infect humans, other mammals, including livestock and companion animals, and avian species. Human coronaviruses are capable of causing illnesses ranging from the common cold to more severe diseases such as Middle East respiratory syndrome (MERS, fatality rate ≈34%). SARS-CoV-2

2065-648: The centre of a major infection cluster in Germany, 15 per cent of a population sample tested positive for antibodies . Screening for COVID-19 in pregnant women in New York City , and blood donors in the Netherlands, found rates of positive antibody tests that indicated more infections than reported. Seroprevalence -based estimates are conservative as some studies show that persons with mild symptoms do not have detectable antibodies. Initial estimates of

2124-760: The city of Shanghai, China. For the first two years of the pandemic, no specific and effective treatment or cure was available. In 2021, the European Medicines Agency's (EMA) Committee for Medicinal Products for Human Use (CHMP) approved the oral antiviral protease inhibitor , Paxlovid (nirmatrelvir plus the HIV antiviral ritonavir ), to treat adult patients. FDA later gave it an EUA. Most cases of COVID-19 are mild. In these, supportive care includes medication such as paracetamol or NSAIDs to relieve symptoms (fever, body aches, cough), adequate intake of oral fluids and rest. Good personal hygiene and

2183-484: The cumulative number of infected individuals (including asymptomatic and undiagnosed infections and excluding vaccinated infected individuals). It is expressed in percentage points. Other studies refer to this metric as the infection fatality risk . In November 2020, a review article in Nature reported estimates of population-weighted IFRs for various countries, excluding deaths in elderly care facilities, and found

2242-441: The development of various vaccine platforms during early 2020. The initial focus of SARS-CoV-2 vaccines was on preventing symptomatic and severe illness. The COVID-19 vaccines are widely credited for their role in reducing the severity and death caused by COVID-19. As of March 2023, more than 5.5 billion people had received one or more doses (11.8 billion in total) in over 197 countries. The Oxford-AstraZeneca vaccine

2301-460: The existing record, then make further attempts during which (the members of) the team hoped to reach speeds of up to 1,600 km/h (1,000 mph). The effort was originally run by Richard Noble who was the leader of the ThrustSSC project, however following funding issues in 2018, the team was bought by Ian Warhurst and renamed Bloodhound LSR. Later the project was indefinitely delayed due to

2360-513: The eyes, nose, or mouth with unwashed hands. Those diagnosed with COVID-19 or who believe they may be infected are advised by healthcare authorities to stay home except to get medical care, call ahead before visiting a healthcare provider, wear a face mask before entering the healthcare provider's office and when in any room or vehicle with another person, cover coughs and sneezes with a tissue, regularly wash hands with soap and water and avoid sharing personal household items. A COVID-19 vaccine

2419-474: The general public beginning in December 2020, made available through government and international programs such as COVAX , aiming to provide vaccine equity . Treatments include novel antiviral drugs and symptom control. Common mitigation measures during the public health emergency included travel restrictions , lockdowns , business restrictions and closures, workplace hazard controls , mask mandates , quarantines, testing systems, and contact tracing of

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2478-665: The infected. The pandemic caused severe social and economic disruption around the world, including the largest global recession since the Great Depression . Widespread supply shortages , including food shortages , were caused by supply chain disruptions and panic buying . Reduced human activity led to an unprecedented temporary decrease in pollution . Educational institutions and public areas were partially or fully closed in many jurisdictions, and many events were cancelled or postponed during 2020 and 2021. Telework became much more common for white-collar workers as

2537-487: The issue of respiratory failure. Existing drugs such as hydroxychloroquine , lopinavir/ritonavir , and ivermectin are not recommended by US or European health authorities, as there is no good evidence they have any useful effect. The antiviral remdesivir is available in the US, Canada, Australia, and several other countries, with varying restrictions; however, it is not recommended for use with mechanical ventilation, and

2596-576: The majority of the unreported 9.5 million deaths believed to be direct deaths due the virus, rather than indirect deaths. Some deaths were because people with other conditions could not access medical services . A December 2022 WHO study estimated excess deaths from the pandemic during 2020 and 2021, again concluding ≈14.8 million excess early deaths occurred, reaffirming and detailing their prior calculations from May as well as updating them, addressing criticisms. These numbers do not include measures like years of potential life lost and may make

2655-495: The official names COVID-19 and SARS-CoV-2 on 11 February 2020. Tedros Adhanom Ghebreyesus explained: CO   for corona , VI   for virus , D   for disease and 19 for when the outbreak was first identified (31 December 2019). WHO additionally uses "the COVID-19 virus" and "the virus responsible for COVID-19" in public communications. WHO named variants of concern and variants of interest using Greek letters . The initial practice of naming them according to where

2714-534: The outbreak a public health emergency of international concern (PHEIC) on 30 January 2020, and assessed the outbreak as having become a pandemic on 11 March. COVID-19 symptoms range from asymptomatic to deadly, but most commonly include fever, sore throat , nocturnal cough , and fatigue. Transmission of the virus is often through airborne particles . Mutations have produced many strains (variants) with varying degrees of infectivity and virulence . COVID-19 vaccines were developed rapidly and deployed to

2773-407: The pandemic 2021's leading cause of death . The time between symptom onset and death ranges from   6 to 41 days, typically about 14 days. Mortality rates increase as a function of age. People at the greatest mortality risk are the elderly and those with underlying conditions. The infection fatality ratio (IFR) is the cumulative number of deaths attributed to the disease divided by

2832-495: The pandemic evolved. Misinformation circulated through social media and mass media , and political tensions intensified . The pandemic raised issues of racial and geographic discrimination , health equity , and the balance between public health imperatives and individual rights . The WHO ended the PHEIC for COVID-19 on 5 May 2023. The disease has continued to circulate, but as of 2024, experts were uncertain as to whether it

2891-478: The population's age structure and the age-specific pattern of infections. There have also been reviews that have compared the fatality rate of this pandemic with prior pandemics, such as MERS-CoV. For comparison the infection mortality rate of seasonal flu in the United States is 0.1%, which is 13 times lower than COVID-19. Another metric in assessing death rate is the case fatality ratio (CFR), which

2950-462: The risk of dying from seasonal influenza . In December 2020, a systematic review and meta-analysis estimated that population-weighted IFR was 0.5% to 1% in some countries (France, Netherlands, New Zealand, and Portugal), 1% to 2% in other countries (Australia, England, Lithuania, and Spain), and about 2.5% in Italy. This study reported that most of the differences reflected corresponding differences in

3009-496: The same infection may have different symptoms, and their symptoms may change over time. Three common clusters of symptoms have been identified: one respiratory symptom cluster with cough, sputum , shortness of breath, and fever; a musculoskeletal symptom cluster with muscle and joint pain, headache, and fatigue; a cluster of digestive symptoms with abdominal pain, vomiting, and diarrhoea. In people without prior ear, nose, and throat disorders, loss of taste combined with loss of smell

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3068-607: The speed at which sound propagates through the medium. In gases, sound travels longitudinally at different speeds, mostly depending on the molecular mass and temperature of the gas, and pressure has little effect. Since air temperature and composition varies significantly with altitude, the speed of sound, and Mach numbers for a steadily moving object may change. In water at room temperature supersonic speed means any speed greater than 1,440 m/s (4,724 ft/s). In solids, sound waves can be polarized longitudinally or transversely and have higher velocities. Supersonic fracture

3127-411: The time from symptom onset to death has ranged from two to eight weeks. Prolonged prothrombin time and elevated C-reactive protein levels on admission to the hospital are associated with severe course of COVID-19 and with a transfer to intensive care units (ICU). Between 5% and 50% of COVID-19 patients experience long COVID , a condition characterised by long-term consequences persisting after

3186-694: The typical convalescence period of the disease. The most commonly reported clinical presentations are fatigue and memory problems, as well as malaise , headaches, shortness of breath , loss of smell, muscle weakness , low fever and cognitive dysfunction . Many countries attempted to slow or stop the spread of COVID-19 by recommending, mandating or prohibiting behaviour changes, while others relied primarily on providing information. Measures ranged from public advisories to stringent lockdowns. Outbreak control strategies are divided into elimination and mitigation. Experts differentiate between elimination strategies (known as " zero-COVID ") that aim to completely stop

3245-405: The use of an afterburner . Due to its ability to supercruise for several hours and the relatively high frequency of flight over several decades, Concorde spent more time flying supersonically than all other aircraft combined by a considerable margin. Since Concorde's final retirement flight on November 26, 2003, there are no supersonic passenger aircraft left in service. Some large bombers , such as

3304-543: The variants were identified (e.g. Delta began as the " Indian variant") is no longer common. A more systematic naming scheme reflects the variant's PANGO lineage (e.g., Omicron 's lineage is B.1.1.529) and is used for other variants. SARS-CoV-2 is a virus closely related to bat coronaviruses , pangolin coronaviruses, and SARS-CoV . The first known outbreak (the 2019–2020 COVID-19 outbreak in mainland China ) started in Wuhan , Hubei, China, in December 2019. Many early cases were linked to people who had visited

3363-443: Was accidentally released from a laboratory have been proposed, as of 2021 these were not supported by evidence. Official "case" counts refer to the number of people who have been tested for COVID-19 and whose test has been confirmed positive according to official protocols whether or not they experienced symptomatic disease. Due to the effect of sampling bias , studies which obtain a more accurate number by extrapolating from

3422-457: Was still a pandemic. Pandemics and their ends are not well-defined, and whether or not one has ended differs according to the definition used. As of 24 November 2024, COVID-19 has caused 7,075,455 confirmed deaths. The COVID-19 pandemic ranks as the fifth- deadliest pandemic or epidemic in history . In epidemiology , a pandemic is defined as "an epidemic occurring over a very wide area, crossing international boundaries, and usually affecting

3481-509: Was the most widely used. According to a June 2022 study, COVID-19 vaccines prevented an additional 14.4 million to 19.8 million deaths in 185 countries and territories from 8 December 2020 to 8 December 2021. On 8 November 2022, the first recombinant protein-based COVID-19 vaccine (Novavax's booster Nuvaxovid ) was authorised for use in adults in the United Kingdom. It has subsequently received endorsement/authorisation from

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