It's been a year since the World Health Organisation (WHO) declared COVID-19 as a pandemic and India imposed a coronavirus lockdown on March 22, 2020. During the lockdown, new words such as quarantine, social distancing, asymptomatic and comorbidity became a part of our daily vocabulary. We also learned a lot about the COVID-19 virus during the lockdown. 
 
As the world still grapples with the spread of the deadly virus, here's a look at some interesting facts about COVID-19
 
What is COVID-19?
According to World Health Organisation (WHO) COVID-19 is caused by a new coronavirus called SARS-CoV-2. WHO first learned of this new virus in December 2019 after cluster of cases were reported in Wuhan province of China.

Which tests are used to detect COVID-19?
Two most common tests to detect COVID–19 infection are RT-PCR test and antigen test.
 
A Polymerase chain reaction test (PCR) is a molecular test used to determine if you are infected by SARS-CoV-2 infection. In this test, a swab is used to collect samples from the nose and throat of the person getting tested. These tests can be done in a clinic, hospital and authorised health centres. You can also get your samples collected at home and send it to the lab for analysis. Generally it takes 2-3 days to get the test results but sometimes results can be obtained in 24 hours.
 
WHO says, Rapid antigen tests (sometimes known as a rapid diagnostic test – RDT) detect viral proteins (known as antigens). Samples are collected from the nose and/or throat with a swab. These tests are cheaper than PCR and will offer results more quickly, although they are generally less accurate
(Source: https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/coronavirus-disease-covid-19)
 
What are the classic sypmtoms of COVID-19?
Some of the symptoms of COVID-19 include fever, breathing trouble, dry cough, fatigue and loss of smell and taste. Symptoms begin one to fourteen days after exposure to the virus.
 
Who are most vulnerable to COVID-19?