COVID turns 5: facts and remaining mysteries about the virus

Five years ago, a mysterious new virus emerged in Wuhan, China, marking the start of a global health crisis.

Initially anonymous, the virus and the illness it caused would eventually spark a global pandemic. The crisis has exposed stark inequities in global health systems and transformed public perceptions of the management of emerging and deadly pathogens. Five years later, the virus is widely known as COVID-19.

Why it matters

The virus persists, but widespread immunity from vaccinations and previous infections has made it less deadly than early in the pandemic. Even if it is no longer among the main causes of death, its continued evolution requires vigilant monitoring by scientists.

COVID-19 has claimed the lives of approximately 20 million people worldwide. While the World Health Organization (WHO) member countries have officially reported more than 7 million deaths, the real toll would be at least three times higher, according to WHO estimates.

What you need to know

However, COVID-19 has continued to claim lives at an average rate of about 900 deaths per week over the past year in the United States, according to data from the Centers for Disease Control and Prevention (CDC).

The elderly remain the most vulnerable to the coronavirus. During last winter in the United States, people aged 75 and older accounted for nearly half of all hospitalizations and hospital deaths due to COVID-19, according to the CDC.

Covid-19 vaccines

Scientists and vaccine manufacturers have successfully developed COVID-19 vaccines at record speed, saving tens of millions of lives around the world. These vaccines have become the cornerstone of efforts to restore normalcy.

Less than a year after China identified the new virus, health regulators in the United States and the United Kingdom approved vaccines developed by Pfizer and Moderna. These breakthroughs were made possible by years of prior research, including Nobel Prize-winning discoveries that were instrumental in the advancement of mRNA vaccine technology.

Today, vaccine options include a more conventional formulation from Novavax, as well as other alternatives adopted in some countries. Although distribution to low-income countries initially lagged, the World Health Organization (WHO) estimates that more than 13 billion COVID-19 vaccine doses have been administered globally since 2021.

Although highly effective in preventing serious illness, hospitalizations and death, COVID-19 vaccines are not without limitations. They have demonstrated strong safety profiles with only rare serious side effects, but their protection against mild infections wanes after a few months.

Similar to flu vaccines, COVID-19 vaccines require regular updates to keep pace with the ever-evolving virus, fueling public frustration with repeated vaccinations. Researchers are exploring next-generation options, including nasal vaccines, which could potentially provide stronger protection against infections.

Mysteries

The origins of the virus remain unclear, although scientists believe it likely originated in bats. It is suspected that it jumped to another species, perhaps raccoon dogs, civet cats or bamboo rats, before infecting humans. The first human cases appeared in late November 2019, linked to a market in Wuhan where such animals were handled and slaughtered.

This route of transmission is well documented and is likely responsible for the first SARS outbreak. However, this remains to be proven in the case of the COVID-19 virus. Adding to the uncertainty, Wuhan is home to several research laboratories specializing in collecting and studying coronaviruses, sparking an ongoing debate over whether the virus could have escaped from any of these facilities.

Determining the origins of the virus is a complex scientific challenge under any circumstances, but the task has been further complicated by political disputes and accusations from international researchers that China has concealed crucial evidence.

The exact origin of the pandemic could remain a mystery for years and may never be fully discovered.

What people say

WHO Director Tedros Adhanom Ghebreyesus told the Associated Press: “We can’t talk about COVID in the past, since it’s still here.”

In a press release published Monday, The WHO said: “As we mark this milestone, let us take a moment to honor the lives changed and lost, recognize those suffering from COVID-19 and long COVID, express our gratitude to the health workers who have sacrificed so much to care for us and Let’s commit to learning from COVID-19 to build a healthier future.

What’s next

Like all viruses, the COVID-19 virus undergoes genetic mutations as it replicates, a natural process that has shaped its evolution. Scientists have classified these virus variants using Greek letters: alpha, beta, gamma, delta and omicron.

The omicron subvariant currently dominant in the United States, known as XEC, accounted for 45% of circulating strains in the two weeks ending Dec. 21, according to the CDC.

This article includes reporting from the Associated Press.