![]() Therefore, when considering how SARS-CoV-2 will evolve, experts think it makes evolutionary sense for the virus to become less deadly and more contagious. For example, the H1N1 influenza virus associated with the 1918 “Spanish flu” later became the far less deadly 2009 “swine flu.” There are instances in history of viruses evolving to become less dangerous. In an ideal world for most viruses, they will cause infections that do not interfere with someone’s ability to go out and spread the virus as much as possible, or even better, cause no noticeable symptoms at all. This means that in most cases, the virus does not want to kill or cause severe illness in its host, as doing so limits its ability to reproduce and spread. ![]() The ultimate goal of a virus is to replicate and circulate as many copies of its RNA, or genes, as possible. ![]() This is what the SARS-CoV-2 variant, Omicron, seems to be doing. What do scientists expect in future coronaviruses?įrom an evolutionary perspective, it is in a virus’s best interest to become less deadly and more contagious. As of January 2022, the Omicron variant has caused more than 96% of COVID-19 cases in the United States. The CDC has identified the Delta and Omicron strains as variants of concern. According to current estimates, the currently circulating coronavirus has undergone around a hundred different mutations so far. While its associated disease COVID-19 has a lower mortality rate than SARS and MERS, SARS-CoV-2 is also more contagious. This means it was causing widespread global illness.Īlthough the precise source of SARS-CoV-2 remains unknown, some early experts think it may have started in bats. On March 11, 2020, the World Health Organization (WHO) declared COVID-19 a global pandemic. However, this may simply be the first place where researchers identified the infection from the virus. Some researchers think SARS-CoV-2, which causes the disease COVID-19, first evolved to cause human infections in China around December 2019. However, this number may be inaccurate because of a lack of case documentation. The mortality rate associated with MERS infections is 35%. As of 2019, only two infections affected people living in the United States, both of which occurred in 2014. They called it MERS-CoV (Middle East Respiratory Syndrome coronavirus), or MERS.Īlthough it is less common now, MERS continues to cause sporadic, localized outbreaks in some parts of the world, primarily the Arabian Peninsula. Researchers identified the next species of coronavirus to cause major disease in Saudi Arabia in September 2012. However, the virus is likely still in existence to some extent.ĭuring the SARS outbreak, the illness had a 9.6% mortality rate. Since 2004, there have been no reported human cases of SARS infections. Three species of coronavirus can cause serious and sometimes even fatal infections:Ĭommonly referred to as SARS, health experts first identified this virus in Southern China in November 2002. The human immune system is not familiar with these viruses, so they tend to cause serious illness and spread easily. In the past two decades, some coronaviruses have evolved in animal species to the point where they can cause infections in humans. ![]() There are seven types of coronavirus known to cause illness in humans: Of the hundreds of viruses in the coronavirus family, the majority cause mild-to-moderate respiratory illnesses that share similarities to the common cold. ![]()
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