After two years of strict COVID-19 lockdowns and travel advisories, there are signs of a return to normal in Canada and other parts of the world as restrictions are being lifted.
But even though new COVID-19 cases and deaths are on the decline globally, the pandemic is far from over, according to the World Health Organization (WHO) and other experts.
“It’s far too early to declare victory over COVID-19,” said WHO Secretary-General Dr. Tedros Adhanom Ghebreyesus last week.
“There are still many countries with high rates of hospitalization and death, and low rates of vaccine coverage and with high transmission. The threat of a new and more dangerous variant remains very real.”
To date, more than 450 million people have been infected with COVID-19 and upwards of six million have died, according to a tally by Johns Hopkins University.
On the second anniversary of COVID-19 being characterized as a pandemic by the WHO, Global News takes a look some past pandemics — recent and old — and how they ended.
1918 - Spanish flu
The influenza pandemic that broke out in 1918 during the First World War was the most devastating flu outbreak of the 20th century.
It was caused by the H1N1 virus and may have originated from an avian reservoir, in other words a bird, according to experts. Like COVID-19, this pandemic was caused by a respiratory illness.
Even though its not clear where exactly the pandemic started from it was commonly referred to as the Spanish flu.
It is estimated that 500 million people — or one-third of the world’s population — became infected with the virus and at least 50 million died.
Dr. Donald Vinh, an infectious disease specialist and medical microbiologist at the McGill University Health Centre (MUHC), said this pandemic peaked over a span of about two years, causing mass deaths. There were three waves.
Even though the peak activity declined in 1919 through a combination of viral biology, medicine and public health measures, H1N1 “was never really gone”, said Vinh. It did simmer down, but didn’t necessarily end, he added.
Its progeny continues to exist and circulate to this day, Vinh said.
While the public health measures were effective and partly contributed to ending the 1918 pandemic, it was ultimately a case of a huge population getting infected and many people dying that led to the end of the Spanish flu, according to Dr. Barry Pakes, York Region medical officer of health and assistant professor at the University of Toronto.
1980s - HIV/AIDS
In the 1980s, the AIDS pandemic affected hundreds of thousands of people worldwide.
The AIDS (acquired immunodeficiency syndrome) disease is caused by the human immunodeficiency virus (HIV).
HIV is transmitted through the exchange of bodily fluids, such as such as blood, breast milk and sexual interaction via semen and vaginal secretions.
The fight against HIV dramatically changed when treatments in the form of antiretroviral drugs became available, making HIV a “tolerable illness” in some parts of the world, said Pakes.
The year 1987 proved to be a pivotal one for the AIDS pandemic as the U.S. FDA approved the first antiretroviral drug, zidovudine (AZT), as a treatment for HIV.
Even though it is no longer considered a pandemic, HIV continues to be a “major global public health issue”, according to the WHO.
The UN health body estimates that 36.3 million people have so far died from HIV. And at the end of 2020, there were an approximately 37.7 million people living with HIV — over two-thirds in the African region.
To date, there has been no cure nor vaccine developed for this deadly virus.
Thanks to effective prevention and diagnosis, HIV infection has become “a manageable chronic health condition, enabling people living with HIV to lead long and healthy lives,” WHO says.
Vinh said HIV was brought under control through public health measures and development of medications.
“Those developments continue to this day”, he added.
2003 - SARS
Before COVID-19, the world experienced another coronavirus-related pandemic with the SARS outbreak in 2003.
The first cases of the original SARS-CoV virus were identified in southern China in November 2002, but it wasn’t until mid-March in 2003 when SARS was recognized by WHO as a global threat.
Compared to COVID-19, SARS was less transmissible but much more deadly, with a death rate of 10 per cent versus one, Pakes said.
Between November 2002 and July 2003, a total of 8,098 cases of SARS were detected in 26 countries, with 774 related deaths, according to the WHO.
Read more: What happened to… SARS?
Despite testing in animal trials, no SARS vaccines were approved for use in humans. Antiviral medication Ribavirin and corticosteroids were used extensively to treat patients.
The spread of the virus was contained through public health measures, including quarantining, mask-wearing, travel advisories, contact tracing, exit screening, restrictions on gatherings and other steps taken worldwide.
That experience of the global response helped prepare us for COVID-19, said Pakes.
By July 2003, the global outbreak was brought under control as more and more countries were declared “SARS-free”.
Since 2004, no new SARS cases have been reported anywhere in the world.
Vinh said SARS’ “high pathogenicity” — in other words, the ability to cause severe disease — was a contributing factor to “why it extinguished” in less in than a year.
2009 - influenza
The 2009-10 influenza pandemic was also caused by the H1N1 virus, making it a derivative of the original H1N1 pandemic of 1918.
Fortunately, the global impact of this flu pandemic was much less in terms of the number of countries that were affected, said Vinh.
A vaccine was developed and quickly deployed within the first year of the pandemic.
Advanced technologies, global surveillance of circulating influenza virus strains and antiviral medications as well as public health measures all played a role in getting the pandemic under control, said Vinh.
In comparison to 1918, countries also had the advantage of an advanced medical system, including intensive care units (ICUs) and other lifesaving support during critical illness, he added.
“A variety of factors — public health, medicine, vaccination — all of those measures allowed the subsequent pandemic flus to have less of an impact,” said Vinh.
Even though most cases were mild, it is estimated the 2009 pandemic killed between 100,000 to 400,000 people worldwide over the course of one year, according to the WHO.
What’s next for COVID-19?
Based on the experience of past pandemics, complete eradication of COVID-19 from the face of the Earth is not a realistic goal, said Vinh.
“Eradication has only essentially occurred for smallpox and possibly SARS,” he said.
So, realistically our aim should be to control the virus and get to the endemic state, Vinh added.
“We will have to keep SARS-CoV-2 at the forefront of our mind.”
Going forward, Vinh predicted more waves of high activity followed by quiet periods, with local outbreaks here and there.
Pakes said from the direction we’re going in now, COVID-19 is transitioning to becoming “more endemic and less pandemic,” but added, “I wouldn’t say we’re nearing the end.”
To monitor new variants, testing will remain a critical part of the pandemic response, said WHO COVID-19 technical lead Dr. Maria Van Kerkhove during a press conference this week.
“We need to keep a good handle on this virus. We need to have a good system in place to be able to check the changes and to understand what those changes in the virus mean,” Van Kerkhove said.
“The pandemic is far from over.”