This May Be the COVID Variant Scientists Are Dreading

A brand new subvariant is starting to surge, and there are signs this one can dodge our immunity.

COVID-19 cases are increasing again in the United Kingdom, potentially signaling a future surge in infections in the United States and other countries.

A pair of new subvariants of the dominant Omicron variant—BA.4 and BA.5—appear to be driving the uptick in cases in the U.K. Worryingly, these subvariants seem to partially dodge antibodies from past infection or vaccination, making them more transmissible than other forms of the SARS-CoV-2 virus.

There are also some suggestions that the new subvariants have evolved to target the lungs—unlike Omicron, which usually resulted in a less dangerous infection of the upper respiratory tract.

But there’s good news amid the bad. While cases are going up in the U.K., hospitalizations and deaths are increasing more slowly or even declining so far. “This could mean higher transmissible variants, BA.4 or 5, are in play, [and] these variants are much less severe,” Edwin Michael, an epidemiologist at the Center for Global Health Infectious Disease Research at the University of South Florida, told The Daily Beast.

The trends could change, of course, but the decrease in deaths is an encouraging sign that, 31 months into the pandemic, all that immunity we’ve built up–at the cost of half a billion infections and tens of billions of dollars’ worth of vaccines—is still mostly holding.

As far as COVID goes, things were really looking up in the U.K. until recently. COVID cases steadily declined from their recent peak of 89,000 daily new infections in mid-March. Deaths from the March wave peaked a month later at around 330 a day.

By early June cases and deaths were near their pandemic lows. Then came BA.4 and BA.5. The grandchildren of the basic Omicron variant that first appeared in the fall of 2021, BA.4 and BA.5 both feature a trio of major mutations to their spike protein, the part of the virus that helps it to grab onto and infect our cells.

Eric Bortz, a University of Alaska-Anchorage virologist and public-health expert, described BA.4 and BA.5 as “immunologically distinct sublineages.” In other words, they interact with our antibodies in surprising new ways.

The European Center for Disease Prevention and Control—the European Union’s answer to the U.S. Centers for Disease Control and Prevention—labeled BA.4 and BA.5 “variants of concerns” back in mid-May. Two weeks later the two new subvariants began the gradual process of overtaking older forms of Omicron in the U.K. That’s when cases began increasing again.

It doesn’t help that the U.K. like most countries—China is a big exception—has lifted almost all restrictions on schools, businesses, crowds and travel. Those restrictions helped to keep down cases, but were broadly unpopular and came at a high economic cost.

“There’s a disconnect between the actuality of how infections are happening… and how people are deciding not to take very many precautions,” John Swartzberg, a professor emeritus of infectious diseases and vaccinology at the University of California-Berkeley's School of Public Health, told The Daily Beast. He described it as “COVID fatigue… 100 percent of the world’s population must have it by now.”

The combination of a fully reopened economy and new COVID subvariants had an immediate effect. The U.K. Health Security Agency registered 62,228 new infections in the week ending June 10, a 70 percent uptick over the previous week. COVID hospitalizations grew more slowly over the same period, spiking 30 percent to 4,421.

COVID fatalities actually dropped, however—sliding 10 percent to 283. Deaths tend to lag infections by several weeks, of course, so it should come as no surprise if the death rate flattens or bumps up later this month or early next month.

But it’s possible it won’t. Yes, BA.4 and BA.5 are more transmissible, owing to that mutated spike protein. But that doesn’t mean they’re going to kill a lot of people. Despite their unusual qualities, it could be that BA.4 and BA.5 aren’t actually more dangerous than previous subvariants.

Bortz sketched out one possibility, that BA.4 and BA.5 are “immune-evasive enough to infect, but generally not evasive enough to counteract acquired immunity from vaccines and/or prior infection.”

Of course, immunity varies from community to community, country to country. The U.K.’s 67 million people have, for their part, built up pretty serious immunity over the past two-and-a-half years.

Tens of millions of U.K. residents have natural antibodies from past infection. 87 percent of the population is fully vaccinated. 68 percent is boosted. All those antibodies might not prevent breakthrough infections, but they do tend to prevent serious breakthrough infections.

How bad the current surge in cases gets depends to a great extent on the durability of those antibodies. Immunity, whether from past infection or vaccines, tends to wane over time. But how fast it wanes, and to what effect, is unpredictable.

It’s possible widespread immunity holds and the swelling BA.4 and BA.5 wave in the U.K. crests in a few weeks without making a whole lot more people sick—or killing them. That’s the best-case scenario given the lack of political will, and public support, for a new round of restrictions. “If higher cases would not lead to significant disease or deaths, then we may be able to live with this virus,” Michael said.

The worst-case scenario is that BA.4 and BA.5 prove more capable of evading our antibodies than experts currently anticipate. Keep an eye on the hospitalization stats. If COVID hospitalizations start increasing in proportion to the growth in cases, it’s a sign the new sublineages are dodging our hard-won immunity.

In that case, a big spike in deaths is sure to follow.

That could be a big red flag for the Americas. COVID variants tend to travel from east to west, globally. New variants and subvariants tend to appear in the United States a few weeks after becoming dominant in the U.K. At present, BA.4 and BA.5 account for just a fifth of new cases in the U.S. Expect that proportion to increase.

The problem for Americans is that they’re much less protected than Britons. Yes, Americans have a lot of antibodies from past infection, but they’re also a lot less likely to be vaccinated—and even less likely to be boosted. Just 67 percent of Americans are fully vaxxed. A little over a third of the U.S. population has gotten a booster.

So if BA.4 and BA.5 end up causing a surge in deaths in the U.K., they’re likely to inflict an even greater death toll on the other side of the Atlantic Ocean. “We’re sort of in this zone now, betwixt and between,” Swartzberg said. “It’s unclear which way things are going to go.”

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