On March 11, 2020, the World Health Organization declared that the coronavirus crisis was now a global pandemic.
The WHO estimates that nearly 15 million people were killed either by the novel coronavirus or by its impact on overwhelmed health systems during the first two years of the pandemic.
We look back at the first year of the pandemic, known as COVID-19.
In December 2019, doctors in the city of Wuhan, in central China, began treating a group of patients with pneumonia.
The city of Hebei, a northern province bordering Beijing, has more than eleven million inhabitants.
On December 31, 2019, China alerted the World Health Organization (WHO) about the patients.
The WHO is informed that the patients have been quarantined and that the authorities have begun to track the patients' movements to trace the source of the diseases.
On January 6, a Taiwanese citizen fell ill with flu-like symptoms two weeks after returning from a trip to Wuhan. Taiwanese doctors reported that the patient was quarantined.
This indicates that the source of the disease could have a longer incubation period, of approximately fourteen days.
The cause is unknown, but it is linked to the Huanan seafood wholesale market, which also sold animals.
This leads doctors to suggest that the disease is zoonotic, meaning that it can be transmitted between animals and humans.
In a study published in the journal Nature (Monday, February 3, 2020), scientists claim that the virus could have originated in bats.
Researchers at the Wuhan Institute of Virology examined the genome sequence of the virus taken from five patients at the beginning of the outbreak.
They claim that the new coronavirus is 96% identical, at the whole genome level, to a bat coronavirus.
On January 7, a Chinese woman working for a South Korean company fell ill with flu-like symptoms. The following day, the Korean Centers for Disease Control and Prevention diagnosed pneumonia.
On the 8th, Chinese state media reported that laboratory experts had found a new coronavirus in 15 of the 59 flu cases in China, but added that further research needed to be conducted before reaching a conclusion.
On January 9, China transmitted the virus's genome to laboratories around the world.
On January 11, a 61-year-old man died in Wuhan after developing severe pneumonia. It turned out he had been admitted to the hospital for a suspected fever on December 27.
Infections in China continue to multiply and, within two weeks, cases are reported in Thailand, Japan and South Korea, and then in other Asian countries.
With the Chinese New Year fast approaching, concerns are growing about the spread of the virus. In China, millions of people are preparing to travel to visit their families across the country and abroad.
Airports around the world are beginning to screen people arriving from Wuhan for high temperatures or signs of fever.
On January 21, the U.S. Centers for Disease Control and Prevention confirmed they had the first American case of the virus. The patient, in Washington state, had recently returned from Wuhan.
Nancy Messonnier, MD, director of the National Center for Immunization and Respiratory Diseases at the CDC, told Americans: "We are preparing to deal with the expected, the unexpected, and the unimaginable."
Then the final confirmation arrives. Scientists say the virus looks like this:
Like SARS, it is a coronavirus, but this one is different and is called the new coronavirus.
The virus was later named "severe acute respiratory syndrome coronavirus 2" (SARS-CoV-2).
The disease it causes is known as COVID-19.
The following day, China quarantined the entire city of Wuhan and other cities in Hubei province, located in the center of the country.
This is a large-scale quarantine. A large-scale quarantine, unlike any before it.
With the number of cases continuing to rise, both in China and abroad, countries around the world are beginning to evacuate their citizens.
By the end of January, twenty-three countries were reporting cases of coronavirus on all continents, and the World Health Organization declared that the Wuhan outbreak should now be treated as a global health emergency.
The Director-General, Dr. Tedros Adhanom Ghebreyesus, made the announcement during a meeting at the United Nations headquarters in Geneva.
"The decision to declare a PHEIC (Public Health Emergency of International Concern) was made primarily because of signs of human-to-human transmission outside of China," explains Mr. Ghebreyesus.
Doctors fear that the virus could spread before it is detected if it enters less developed countries.
Around the world, major conferences and trade fairs are being cancelled, cruise ships are being stopped and quarantined, and businesses forced to close their doors are suffering financial losses.
The borders are closed and the tourists are being repatriated.
In March, there were concerns about a global shortage of personal protective equipment (PPE), as demand for equipment for doctors, healthcare workers and, now, the general public, increased.
In the face of growing concern over the spread of the virus, international sporting competitions are being postponed.
At the WHO, Mr. Ghebreyesus declares that the world is facing a pandemic.
"We are deeply concerned by both the alarming levels of spread and severity, and by the alarming levels of inaction. That is why we have determined that COVID-19 can be classified as a pandemic."
During the first European wave, Italy and Spain were hit hard, with hospitals and morgues struggling to cope with the influx of critically ill patients, many of whom did not survive.
Countries around the world have closed their borders and taken measures to contain the virus.
The shopping streets and tourist hotspots are silent.
Throughout the year, treatments such as therapeutic plasma are being sought, older drugs like BCG are being reused in trials, and some drugs like dexamethasone and corticosteroids are proving useful for some hospitalized patients.
Meanwhile, the search for effective vaccines continues.
While lockdowns are leading to a reduction in COVID-19 cases, countries are beginning to tentatively allow businesses to reopen, but the world has changed.
Social distancing and wearing masks in shops and on public transport are becoming mandatory, as scientists learn more about how the virus spreads in droplets and aerosols expectorated (breathed) by infected people.
With the start of the school year and the return to normal life, countries around the world are beginning to experience a second peak in COVID-19 cases.
As the winter holidays approach, establishment closures return and new strict rules are adopted, but the race for COVID-19 vaccines is finally bearing fruit.
Hundreds of vaccines are being researched.
China developed its own vaccines and Russia followed with Sputnik V.
In December 2020, a new mRNA vaccine from Pfizer BioNTech, which does not use live or weakened viruses, was approved in the UK and, within a week, it was licensed and deployed.
Margaret Keenan, 90, was the first beneficiary.
The next vaccine to be approved is a Moderna product, which also belongs to the new category of mRNA vaccines. These vaccines use a portion of the virus's genetic material to prompt our bodies to fight it. This vaccine can also be stored at normal refrigerator temperatures.
Oxford University and AstraZeneca are the next to declare that their more traditional vaccine is effective against COVID-19 and has the added advantage of not needing to be stored at negative temperatures like Pfizer's BioNTech vaccine.
AstraZeneca's COVID-19 vaccine received the green light from the European Medicines Agency in January 2021.
Dozens of countries have suspended the use of the vaccine after unusual but rare blood clots were detected in a small number of vaccinated people.
Studies have since suggested that the more expensive mRNA vaccines made by Pfizer-BioNTech and Moderna offered better protection against COVID-19 and its many variants, and most countries have switched to these vaccines.
In 2023, two scientists whose discoveries led to the new mRNA vaccines received the Nobel Prize in Medicine.
The development of vaccines has helped to slow the spread of the coronavirus and, as the virus mutated into different strains, the vaccines have been modified.
Mathematical modelers at Imperial College London have estimated that vaccines have prevented the deaths of nearly 20 million people worldwide.
Their calculations are based on the first twelve months of vaccine deployment, from December 2020 to December 2021.
They rely on data from 185 countries, but not from China.
In September 2022, a study commissioned by the World Health Organization estimated that 17 million people in Europe were living with symptoms of long varicella between 2020 and 2021.
Symptoms of long COVID include fatigue, body aches, mood swings, cognitive problems, and shortness of breath after initial recovery from COVID infection.
Five years later, the virus has become endemic on all continents.
Lockdowns and social distancing are now just a memory.
Although COVID-19 may not be making headlines like it once did, it is important to remember that it is still circulating.
Health authorities warn that even though COVID-19 has become an established respiratory virus like seasonal flu, the virus will continue to be fatal for some.
