Explainer | Will the coronavirus continue to evolve after Omicron? And what does this mean for the battle against Covid-19

As many countries try to live with Covid-19, the virus itself is relentlessly mutating to be ever more efficient in spreading among the population. Even the Omicron variant, which caused an unprecedented wave of cases around the world in December and is behind China’s current surge in cases, has evolved. The initial Omicron strain, known as BA. 1, has now been outcompeted by its sibling BA. 2, which now accounts for nearly 86 per cent of all sequenced cases, according to the World Health Organization. Beijing sends Covid-19 teams to 10 provinces in push to beat Omicron Here is what scientists think will happen next and how it will affect the future course of the pandemic. Will we see more variants in the future? “We can safely say that we will,” says Wytamma Wirth, a microbiologist with the University of Melbourne. Viruses mutate when “errors” are made while replicating in the cells of their host. Viruses that encode their genome in the host’s RNA – such as Sars-Cov2-2 (the Covid virus), HIV and influenza – are prone to quick mutations. This rapid evolution is part of the reason why there is no effective HIV vaccine yet and people need annual seasonal flu shots. Sars-CoV-2 has so far been slower to evolve than HIV and flu, but its vast reach makes scientists believe there will be more variants in future. When will we see another worrying variant? There is no way to know for sure when a variant will become dominant or whether it will become a variant of concern – one that is highly transmissible, causes more severe diseases or reduces the effectiveness of vaccines. One of the explanations for the large number of mutations is that the virus is able to evolve for long periods of time in the bodies of immunocompromised people, whose suppressed immune systems allow the virus to linger in the body, replicate and mutate for months. Researchers from the University of Melbourne looked at four of the earliest variants of a concern in a study published in Molecular Biology and Evolution in February and found that it took 14 weeks for Alpha to accumulate enough mutations to become a variant of concern, four for Beta, 17 for Gamma and six for Delta. AstraZeneca Covid-19 drug neutralises Omicron sub-variants, says lab study Sebastian Duchene Garzon, who conducted the study with Wirth, said the pace at which mutations appeared had changed in all four variants and this might be the case for future variants. “They can also mix their genomes, such as recombination [when two related viruses inhabit the same cell] which may lead to even faster emergence,” Garzon said. “There is evidence of recombination but it is too soon to tell if it will result in new variants.” The process of recombination means that new variants may emerge more quickly. A recent study from the UK Health Security Agency identified hundreds of examples of recombination in a sublineage of Omicron known as XE, which was 9.8 per cent more transmissible than the BA2 variant. However, it is too soon to say whether this can be classified as a new variant in its own right. What will the new variant of concern be like? Will it be more transmissible or cause more serious illnesses? Scientists believe that a new dominant variant will have to be more efficient at spreading than Omicron so that it can outcompete it – as was the case with past variants – but it is hard to say whether it will cause a more severe clinical outcome. The BA. 2 subvariant of Omicron is about 30 per cent more transmissible than BA. 1, but real world studies showed that it did not pose a greater risk of hospitalising people. Jin Dongyan, a virologist from the University of Hong Kong, said the main trend in viral evolution is to adapt to its host so it becomes non-pathogenic for them, as is the case with influenza and its natural host, waterfowl. “I’m confident and optimistic that the next one will only become less virulent. That would be the direction. After many years of evolution, they will just become non-pathogenic, so Sars-CoV-2 will become less and less pathogenic in humans, that’s the trend,” Jin said. China can learn from Omicron to protect the elderly: health expert “There might be variations sometimes. Sometimes you might get one variant that is slightly more virulent, but that will not be forever. It will very soon be replaced by something else if it is more pathogenic. “Sars-CoV-2 could eventually become the fifth human coronavirus that causes the common cold.” How will that affect the trajectory of the pandemic? The unpredictable natures of the variants means it is difficult to say what the future course of the pandemic will be. Some scientists believe that it will be endemic, meaning the virus will still be present in the community but with predictable prevalence and controllable outcomes. Others are more hesitant because vaccination rates remain low, especially in low-income countries where only 15 per cent of people have been vaccinated. This means the virus can still spread widely, increasing the chance of further mutations.