Evolutionary biologist Jesse Bloom knew it was only a matter of time: The coronavirus would turn into an even more formidable foe, able to dodge the disease-fighting antibodies that protect people after being infected or vaccinated. He even knew which mutation was likely to give it that superpower.

He just didn’t know it would happen quite this fast.

For much of 2020, most people — including most experts — weren’t particularly worried about the virus’s ability to evolve. SARS-CoV-2 was changing, but so far that hadn’t amounted to anything especially concerning. Then, in late fall, it jumped. Distinctive new versions of the virus sparked alarming surges in Brazil, South Africa and the United Kingdom.

In a few short months, variants have become a global preoccupation. Nearly every time public health experts talk about the trajectory of the health crisis, they dwell on the variants, the loose cannon that could wreck hard-won progress.Some experts fear vaccines may be less effective against strains of the coronavirus that were first found in the United Kingdom, South Africa and Brazil. (The Washington Post)

These variants carry not one but a slew of mutations. They appear to have worrisome new abilities, better at spreading or slipping by aspects of immunity.

As scientists work to get a handle on the variants, the situation gives the public a rare front-row seat and real-time view of the unpredictability of viral evolution. The virus is changing, and scientists are preparing for a wide range of possible futures.

“We do have to come to terms with the fact that I’m pretty confident that SARS-CoV-2 is going to be more like influenza, which is with us all the time because the virus is changing, and we have to worry about keeping our vaccines updated,” Bloom said. “On the other hand, I think that a year from now, it’s going to be much less of a problem.”

People like Bloom are building maps of the genetic escape routes the virus could take, so that when mutations inevitably arise, scientists can quickly interpret whether they’re likely to pose a threat.

That doesn’t necessarily mean a world where the pandemic never ends. The outlook is improving as vaccines are rolled out. If vaccines become outdated, they will be updated.

“There will be new variants and new ways in which the virus might be escaping our immune responses a little bit, but that’s the key — it’s probably not going to be that much” of an escape, said Sarah Cobey, who studies viral evolution at the University of Chicago.Fauci says vaccine companies are developing booster shots to combat coronavirus variantsIn a Jan. 27 briefing, members of Biden’s covid-19 response team spoke about current vaccine effectiveness and new data on side effect risks. (Reuters)

In laboratories, scientists are testing whether the current variants remain susceptible to antibodies conjured by natural infection and vaccines. Companies are preparing new versions of vaccines and testing extra booster shots, just in case.

The stealthy, speedy arrival of variants has put scientists in the familiar position of being unable to predict where the virus is headed.

“If you really push virologists, and get them to be honest and not revisionist, the majority, if not all the individuals, in the community were saying, ‘It’ll probably be all right, it’ll probably be fine,’ ” said Paul Duprex, director of the Center for Vaccine Research at the University of Pittsburgh.

The past few months have been a wake-up call: “Don’t think that we are cleverer than evolution.”

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Clues to an escape

Even before the variants emerged, there were hints that scientists had been underestimating the virus’s capacity to change. Starting last spring, a 45-year-old man with a severe autoimmune disease was in and out of a Boston hospital for five months, with what turned out to be an astonishingly long chronic coronavirus infection. By sequencing the virus over different time points, doctors found that the virus was changing rapidly — highlighting the potential for what his team of doctors called “accelerated viral evolution.”