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Common public health mitigation measures during the emergency phase included travel restrictions, lockdowns, business restrictions and closures, workplace hazard controls, mask mandates, quarantines, testing systems, and contact tracing of the infected, which, together with treatments, served to control the pandemic. Treatments include novel antiviral drugs and symptom control. Other preventive measures include social distancing, wearing masks, improving ventilation and air filtration, and quarantining those who have been exposed or are infected. 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. The COVID-19 vaccines have been approved and widely distributed in various countries since December 2020. Mutations have produced many strains (variants) with varying degrees of infectivity and virulence. Infected individuals are typically contagious for 10 days and can spread the virus even if they do not develop symptoms.
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Transmission can also occur if contaminated fluids reach the eyes, nose, or mouth, or, more rarely, through contaminated surfaces. The risk of breathing these in is highest when people are in close proximity, but they can be inhaled over longer distances, particularly indoors. COVID-19 transmits when people breathe in air contaminated by droplets and small airborne particles containing the virus. Severe illness is more likely in elderly patients and those with certain underlying medical conditions. As of 12 June 2023, the pandemic had caused 767,750,089 cases and 6,941,082 confirmed deaths, making it one of the deadliest in history.ĬOVID-19 symptoms range from undetectable to deadly, but most commonly include fever, dry cough, and fatigue. The World Health Organization (WHO) declared the outbreak a public health emergency of international concern (PHEIC) on 30 January 2020, and began referring to it as a pandemic on 11 March 2020. Attempts to contain it there failed, allowing the virus to spread to other areas of Asia and later worldwide.
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The novel virus was first identified in an outbreak in the Chinese city of Wuhan in December 2019. The COVID-19 pandemic, also known as the coronavirus pandemic, is a global pandemic of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
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