The news that the World Health Organisation has declared Covid-19 is no longer a global health emergency reflects the sharp downturn in the number of deaths blamed on the novel coronavirus in recent months.
Recently, fewer than 5,000 people have been dying each week from Covid-19, according to official figures, a significant drop from tens of thousands losing their lives every seven days when the pandemic was at its peak.
The most recent upturn in deaths occurred as recently as December and January as a result of China’s decision to loosen lockdown restrictions, but since then case numbers and fatalities have fallen sharply.
Dr Andrew Freedman, an infectious diseases specialist at Cardiff University in the UK who has followed the pandemic closely, said that while the virus "hasn’t gone away", the risk of death in infected people was now "much lower".
"People getting it now are [typically] getting mild infections and not requiring hospitalisation. There are still some dying, but much fewer," he said.
"Clearly we’ve learnt to live with the virus and will have to continue to do so. It doesn’t represent the emergency that it was."
According to the WHO’s official tally, just over 6.9 million people have died because of Covid-19 since the coronavirus emerged in Wuhan in China in late 2019, although the actual total is likely to be higher.
Covid-19 was declared a global health emergency by the WHO at the end of January 2020 and was declared a pandemic in March of that year.
March 2020 was also the month when the number of deaths globally began to ramp up significantly as the virus spread across the globe, leading to tens of thousands of deaths every week for the next two years.
In that time, however, the world made significant progress in combating the pandemic thanks to the rapid development and testing of vaccines.
Introduced broadly from late 2020, these proved to be highly effective not at stopping the spread of the virus but in preventing people from falling severely ill if they did catch Sars-CoV-2, the virus that causes Covid-19. Particularly notable was the success of vaccines based on messenger RNA (mRNA), a type of genetic material.
Building up immunity
Vaccines using mRNA had been worked on for decades, but it was the huge investments in research sparked by the pandemic that allowed the technology to reach a point where it could be used widely in human vaccines.
Partly because of the power of social media, the pandemic also saw, however, vocal opposition to the shots from the anti-vaccine movement.
Determining the origins of the novel coronavirus that caused the pandemic has proved difficult, with most interest focusing on the possibility of the virus spreading into humans from an animal market in Wuhan or because of a lab leak from the Wuhan Institute of Virology.
Different organisations and reports have come to varying conclusions about the most likely source.
Given its prevalence, Sars-CoV-2 is set to continue to cause large numbers of infections but, said Dr Freedman, people who contract the virus are likely to continue to build up immunity, meaning that infections will mostly be mild.
There have not been signs, he said, of more virulent variants of Sars-CoV-2 developing even though numerous novel sub-variants continue to be detected, so the likelihood is that death rates will not spike again.
"That’s not to say new viruses, which could be a completely different coronavirus or pandemic flu [will not emerge]," he said.
"We can never be complacent and we need to be prepared for the next pandemic whenever that might be and whatever that might be."
Predicting the next pandemic
Scientists have said that the next pandemic is most likely to come from another coronavirus or an influenza virus.
However, there are many other types of virus that could provide the source, among them filoviruses, a group that includes Ebola and Marburg, which both have high fatality rates.
Nipah, a bat-borne henipavirus, has, like Marburg, been highlighted by the vaccine alliance Gavi as a potential cause of the next pandemic. It kills the majority of people infected.
It is not just viruses that spark concern. The Global Antibiotic Research and Development Partnership has described the spread of antibiotic resistance in bacteria as "a slow-moving pandemic that also requires urgent attention".
As antibiotics become less effective, even routine operations become hazardous because of the difficulty in treating post-surgery infections.
