Role of Herd Immunity in COVID-19

Abstract

Coronaviruses are big family of different viruses; some of them cause the common coldin people. Others infect animals, including bats, camels, and cattle. But how did SARS-CoV-2 infect, the new corona virus that causes COVID-19? Here’s what we know about the virus that was first detected in Wuhan, China, in late 2019, and has set off a global pandemic. Experts say SARS-CoV-2 originated in bats. That’s also how the coronaviruses behind Middle East respiratory syndrome (MERS) and severe acute respiratory syndrome (SARS) got started. SARS-CoV-2 made the jump to humans at one of Wuhan’s open-air “wet markets.” They’re where customers buy fresh meat and fish, including animals that are killed on the spot. Still, the Wuhan market didn’t sell bats at the time of the outbreak; that’s why early suspicion also fell on pangolins, also called scaly anteaters, which are sold illegally in some markets in China. Some coronaviruses that infect pangolins are similar to SARS-CoV-2. As SARS CoV-2 spread both inside and outside China, it infected people who have had no direct contact with animals. That meant the virus is transmitted from one human to another. It’s now spreading in the United States and around the globe, meaning that people are unwittingly catching and passing on the coronavirus. This growing worldwide transmission is what a pandemic is now.