Five Years of COVID-19: A Pandemic That Changed the World
Where did the SARS-CoV-2 virus come from?
We don’t know. Scientists think the most likely scenario is that it circulated in bats, like many coronaviruses. They think it then infected another species, probably racoon dogs, civet cats or bamboo rats, which in turn infected humans handling or butchering those animals at a market in Wuhan, where the first human cases appeared in late November 2019. That’s a known pathway for disease transmission and likely triggered the first epidemic of a similar virus, known as SARS. But this theory has not been proven for the virus that causes COVID-19. Wuhan is home to several research labs involved in collecting and studying coronaviruses, fueling debate over whether the virus instead may have leaked from one.
How many people died from COVID-19?
Probably more than 20 million. The World Health Organization has said member countries reported more than 7 million deaths from COVID-19 but the true death toll is estimated to be at least three times higher.
What vaccines were made available?
Scientists and vaccine-makers broke speed records developing COVID-19 vaccines that have saved tens of millions of lives worldwide – and were the critical step to getting life back to normal. Less than a year after China identified the virus, health authorities in the U.S. and Britain cleared vaccines made by Pfizer and Moderna. Years of earlier research — including Nobel-winning discoveries that were key to making the new technology work — gave a head start for so-called mRNA vaccines.
Which variant is dominating now?
Genetic changes called mutations happen as viruses make copies of themselves. And this virus has proven to be no different. Scientists named these variants after Greek letters: alpha, beta, gamma, delta and omicron. Delta, which became dominant in the U.S. in June 2021, raised a lot of concerns because it was twice as likely to lead to hospitalization as the first version of the virus. Then in late November 2021, a new variant came on the scene: omicron. "It spread very rapidly," dominating within weeks, said Dr. Wesley Long, a pathologist at Houston Methodist in Texas. "It drove a huge spike in cases compared to anything we had seen previously."
What do we know about long COVID?
Millions of people remain in limbo with a sometimes disabling, often invisible, legacy of the pandemic called long COVID. It can take several weeks to bounce back after a bout of COVID-19, but some people develop more persistent problems. The symptoms that last at least three months, sometimes for years, include fatigue, cognitive trouble known as "brain fog," pain and cardiovascular problems, among others. Doctors don’t know why only some people get long COVID. It can happen even after a mild case and at any age, although rates have declined since the pandemic’s early years. Studies show vaccination can lower the risk.
Conclusion
The COVID-19 pandemic has had a profound impact on the world, exposing deep inequities in the global health system and reshaping public opinion about how to control deadly emerging viruses. While the virus is still with us, humanity has built up immunity through vaccinations and infections, and it’s less deadly than it was in the pandemic’s early days. However, the virus is evolving, and scientists must continue to track it closely.
Frequently Asked Questions
Q: How many people have died from COVID-19?
A: Probably more than 20 million.
Q: What vaccines were made available to combat COVID-19?
A: Scientists and vaccine-makers developed COVID-19 vaccines that have saved tens of millions of lives worldwide. These vaccines include mRNA vaccines made by Pfizer and Moderna, and a more traditional vaccine made by Novavax.
Q: Which variant of COVID-19 is currently dominating?
A: The omicron variant, which is a subvariant of the original omicron variant, is currently dominating.
Q: What is long COVID?
A: Long COVID is a sometimes disabling, often invisible, legacy of the pandemic that can cause persistent symptoms, including fatigue, cognitive trouble, pain, and cardiovascular problems, among others.
