Search results
Results from the WOW.Com Content Network
Coronavirus diseases are caused by viruses in the coronavirus subfamily, a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, the group of viruses cause respiratory tract infections that can range from mild to lethal.
The transmission of COVID-19 is the passing of coronavirus disease 2019 from person to person. COVID-19 is mainly transmitted when people breathe in air contaminated by droplets/aerosols and small airborne particles containing the virus. Infected people exhale those particles as they breathe, talk, cough, sneeze, or sing.
The COVID-19 vaccines are widely credited for their role in reducing the severity and death caused by COVID-19. [ 128 ] [ 129 ] As of March 2023, more than 5.5 billion people had received one or more doses [ 130 ] (11.8 billion in total) in over 197 countries.
SARS-CoV-2 is the seventh known coronavirus to infect people, after 229E, NL63, OC43, HKU1, MERS-CoV, and the original SARS-CoV. [105] Like the SARS-related coronavirus implicated in the 2003 SARS outbreak, SARS‑CoV‑2 is a member of the subgenus Sarbecovirus (beta-CoV lineage B). [106] [107] Coronaviruses undergo frequent recombination. [108]
The human coronavirus NL63 shared a common ancestor with a bat coronavirus (ARCoV.2) between 1190 and 1449 CE. [76] The human coronavirus 229E shared a common ancestor with a bat coronavirus (GhanaGrp1 Bt CoV) between 1686 and 1800 CE. [77] More recently, alpaca coronavirus and human coronavirus 229E diverged sometime before 1960. [78]
A June 2020 systematic review found a 29–54% prevalence of olfactory dysfunction for people with COVID-19, [59] while an August 2020 study using a smell-identification test reported that 96% of people with COVID-19 had some olfactory dysfunction, and 18% had total smell loss. [60]
On 12 April 2018, the police said that Rakesh Kumar, who leaked the class 12 economics paper, had leaked class 10 mathematics paper also. [40] Consequently, the Central Board of Secondary Education has put in place a system of "encrypted" question papers, which are supposed to be printed by the schools half an hour before the exam starts.
A term for COVID-19 used by former United States president Donald Trump to emphasize that the pandemic started in China. Comirnaty. Main article: Comirnaty. The commercial name for the FDA approved COVID-19 vaccine from Pfizer, released August 21, 2021. It also has several other names or designators used on the actual vials. Community transmission