As Covid-19 turns three, race on to see what’s next

Experts work to determine future development of the virus

The third anniversary of the emergence of an obscure new coronavirus in the Chinese city of Wuhan is coming up fast.

An outbreak that first made just a few sentences on the foreign pages quickly burgeoned into a global pandemic that upended almost every aspect of life and still has profound repercussions.

More than 16 million people are estimated to have died worldwide during the first two years, with trillions spent, economies battered and millions of jobs lost.

Thankfully, the past year has seen a return to normal life, for many at least, as the world tries to put the pandemic behind it.

Yet major questions remain. Is the world past the worst of Covid-19? Are more virulent variants brewing? Will a successor to the dominant Omicron variant emerge? If so, will existing immunity from vaccines and earlier infections hold it at bay?

These were the conundrums preoccupying leading Covid experts as they gathered last week in South Africa.

The gathering, hosted by Durban’s Africa Health Research Institute (AHRI), drew academics and researchers from across the continent, Britain, the United States, Japan, Singapore and Australia. Many were meeting face-to-face for the first time, after nearly three years of Zoom call collaboration.

The high death tolls of 2020 and 2021 may have subsided, but the virus is still circulating widely.

South Africa’s expertise in tracking the HIV virus has meant it has been at the forefront of spotting new coronavirus variants.

Omicron and its bewildering alphabet soup of descendants seem to be mild, at least compared with their viral predecessors, and a mix of vaccinations and earlier infections is credited with giving most people protection against severe disease.

Back to square one?

For many, one of the most pressing topics was whether a major new variant, set to be called Pi, might arise to return us to square one.

Professor Wendy Barclay, a virologist at Imperial College and member of Britain’s advisory committee, Sage, said: “Are we going to see variants arise or future versions of this virus arise which come with more severe outcomes? . . . I still don’t think that’s resolved.”

The most recent variants were not driving transmission or disease in the same way as previous Covid strains, said Professor Miles Davenport, of Australia’s Kirby Institute.

That could be a more hopeful sign that the virus would settle down and become a seasonal infection.

Professor Alexi Sigal of AHRI said there was debate between those who believed the current more benign situation was because vaccines and infections had built an effective immunity wall, and others who thought the virus had evolved significantly to be less harmful but such a shift could happen again in the other direction.

Sigal said that new variants were going to infect people, even if they had been vaccinated. “But if the pathogenicity stays low then you have got this flu-like [situation] but you are not going to have the major effect of this pandemic any more.”

However, if something totally different emerged due to viral evolution “we are really back to square one”.

How a new variant might evolve was also a key question raised at the conference. Researchers said there was growing evidence that people with suppressed immune systems, such as cancer or transplant patients, or those in the later stages of HIV or tuberculosis, might act as a crucible for coronavirus evolution.

While a normal person can quickly clear the virus from their body in days, it appears to linger in the immuno-suppressed for months, replicating and adapting to overcome any immunity they have.

Sigal’s lab followed one infection over many months in an HIV patient and the virus evolved to become more harmful in that time.

Yet while scientists may still be weighing the risks of new variants, they admit the public is increasingly desperate to move on.

Deciding what to do next in such circumstances is a pressing problem for scientists and politicians.

Widespread surveillance, which can be costly, is needed to ensure the new variants can be spotted and tracked, but governments and public health officials also need to decide if they are going to let the virus rip.

There is also the question of whether to further develop our vaccines.

The current crop of jabs might prevent severe disease, but they do not stop the virus spreading, meaning it can pass from one person to another.

That is a problem for the vulnerable immune suppressed people for whom the vaccines do not work, said Barclay.

“There are people all around the world, but certainly in the UK, who are fearful even to resume normal life,” she said. “They can’t go out without wearing a mask and actually they are nervous even then.

“Our vaccines are not really controlling circulation. We are seeing these big waves come and go, with lots and lots of people getting infected.”