This Is How Dangerous the Next COVID Variant Will Be, Experts Predict
Changes to the way the virus behaves are likely to come as it continues to spread.
The COVID-19 pandemic has had no shortage of twists and turns since it began. Time and time again, the SARS-CoV-2 virus has reminded us that even significant leaps in progress can be erased by a simple change in its makeup that makes it easier to spread, more virulent, or both. From the first sign of the Beta variant to the arrival and spread of Delta, the number of case counts and the level of concerns over the effectiveness of existing vaccines has hinged on how the pathogen adapts and changes over time. But could it possibly get worse? According to experts, the next COVID variant we face may be different, but it's not likely to be much more dangerous or deadly than what we've already seen, Salon reports.
Since the earliest days of the pandemic, virologists and disease experts have pointed out that all viruses change and mutate over time as they continue to spread through a population. But according to Monica Gandhi, MD, an infectious disease doctor and professor of medicine at the University of California–San Francisco, it's more likely for them to become more contagious over time rather than deadly as part of an efficient evolution.
"They want more baby virus copies of themselves," Gandhi told Salon. "They don't usually evolve to kill their host more readily because that's actually not very smart."
Similar to animals, the evolution of microscopic pathogens tends to favor the offspring that can more easily reproduce and spread. However, at a certain point, scientists say that a virus can reach "peak fitness," meaning that it becomes as efficiently contagious as it possibly can be.
"More-fit variants can be expected to emerge over time (the occurrence of which will need to be monitored meticulously, as these pose a potential public health threat), but we believe that these will not continue to emerge indefinitely: nothing is infinite in nature, and eventually the virus will reach its form of 'maximum transmission,'" a group of scientists wrote in a June 2021 letter to the editor in the journal Nature. "After then, new variants will provide no further advantage in infectivity. The virus will thus stabilize, and this 'final' variant will prevail and become the dominant strain, experiencing only occasional, minimal variations."
Gandhi also points out that the so-called "Delta-plus" subvariant, officially known as AY.4.2, was the latest version of the virus to gain attention from health officials "just because it could be more transmissible." Fortunately, most research so far points to AY.4.2 posing less of a threat than when the original variant began to spread.
"It looks like it has somewhere between a 12 percent and 18 percent transmission advantage over Delta, so it's not good news in that sense," Christina Pagel, PhD, director of the Clinical Operational Research Unit at University College London, told CNBC. "It's going to make things a bit more difficult, but it's not a massive jump."
Pagel then put the subvariant into perspective to explain how it could be less of a concern despite its ability to spread more quickly. "Delta compared to Alpha was around 60 percent more transmissible, it was doubling every week. This is going up by a percent or two a week—it's much, much slower. So in that sense, it's not a big disaster like Delta was. It will probably gradually replace Delta over the next few months. But there's no sign it's more vaccine resistant, [so] at the moment I wouldn't be panicking about it."
Still, other experts point out that staying on top of the small transformations SARS-CoV-2 undergoes is essential for ensuring vaccines can still be effective against it. "Most of the genetic changes we see in this virus are like the scars people accumulate over a lifetime—incidental marks of the road, most of which have no great significance or functional role," Stuart Ray, MD, vice-chair of medicine for data integrity and analytics at Johns Hopkins University School of Medicine, said in a blog post published by the university. "Updated versions of the current vaccines are being evaluated, but there is no clinical trial evidence yet that variant-specific vaccines would provide significantly greater protection. Though SARS-CoV-2 is changing gradually, it's still much less genetically diverse than influenza."