The BA.2-COVID variant sweeping Asia and Europe is the most unpredictable yet

After spreading to Asia and Europe, the BA.2 subvariant of the novel coronavirus is now dominant in the United States, according to the US Centers for Disease Control and Prevention.

Right now, US COVID cases are at a six-month low. But what happens next in the US and neighboring countries is difficult to predict. Looking for clues in Europe isn’t very helpful, since BA.2 behaved… unpredictably on that continent. Indeed, unpredictability might be exactly what Americans — and everyone else — should expect as the pandemic enters its 28th month.

A patchwork of public health regulations, differing vaccination rates and differing amounts of natural immunity from previous infections mean that no two countries are the same. But even these differences do not fully explain the uneven effect of BA.2.

“The bottom line is there’s no telling what BA.2 will do,” John Swartzberg, professor emeritus of infectious diseases and vaccinology at the University of California-Berkeley’s School of Public Health, told The Daily Beast.

Amidst this confusion, however, at least one thing remains true. As volatile as BA.2 is in terms of countries and populations, you can still protect you yourself by getting vaccinated.

Usually there is a pattern with new COVID lines. An increase in positive tests from clinics, hospitals and sewage samples correlates with a proportional increase in symptomatic infections.

But when it comes to BA.2, “something else seems to be happening,” Baylor College vaccine development expert Peter Hotez told The Daily Beast. “BA.2 is increasing everywhere in terms of the percentage of viruses isolated” in tests, Hotez explained, “yet this leads to many different scenarios in terms of the increase in cases.”

I can’t say for sure that this is due to their vaccination policy or vaccination policy alone.

BA.2 is a highly mutated cousin of the previously dominant BA.1 subvariant of Omicron, the latest major variant – “lineage” is the scientific term – of the SARS-CoV-2 virus. Changes to the spike protein, which helps the virus to acquire and infect our cells, make BA.1 and BA.2 extremely transmissible.

BA.1, which first emerged last fall and quickly led to record infections across much of the world, was the most contagious respiratory virus many virologists had ever seen — until BA.2 emerged a few weeks after its older cousin. BA.2 could be up to 80 percent more transferrable than BA.1, Swartzberg said.

A health worker takes a swab sample from a man scheduled to be tested for COVID-19 at a testing site along a street in Beijing, March 15, 2022.

Jade Gao/AFP via Getty

Because of this, BA.2 eventually supplanted BA.1 and has become the dominant subline in an ever-growing number of countries. It first happened in China, where for more than two years it managed to avoid major COVID outbreaks through a combination of travel restrictions, business closures, careful contact tracing and strict quarantine rules.

BA.2 broke through China’s so-called “zero-COVID” strategy, causing cases to surge in Hong Kong, then neighboring Shenzhen, and then Shanghai. Authorities sealed off each city in turn, but still couldn’t stop the sub-line’s march across the country.

Next up was Europe. Health officials in America watched nervously as BA.2 became dominant in one European country after another. Finally, Europe tends to catch a particular coronavirus line or sub-line a month or six weeks ahead of the US and its neighbors.

But BA.2 did not send clear signals. The first confusing data point was actually not in Europe but in Africa. Curiously, BA.2 was effectively a no-show in South Africa. This country saw a big spike in BA.1 cases in December, and then…nothing. A steady decline in cases even as BA.2 ravaged other large, wealthy countries.

Some European countries have also escaped significant damage from BA.2. Others waver.

The UK and France caught BA.1 in a big way in December and January. Both countries reported record numbers of cases, which thankfully didn’t result in record hospitalizations and deaths thanks to the vaccines. Austria, on the other hand, muddled through BA.1 before taking a enormously Hit by BA.2.

The UK reported a weekly average of 183,000 new daily cases in early January. Three weeks later, France was counting a staggering weekly average of 354,000 daily new cases. The worst day in the UK for BA.1 deaths was February 2, when authorities reported 535 COVID deaths. On France’s worst day of BA.1, February 8, 691 people died from COVID.

A comparison of the two countries is obvious. Not only are they neighbors, they also have about the same number of people — around 67 million. Both have managed to fully vaccinate around three quarters of their population. Both have lifted all major domestic COVID restrictions.

It makes sense that BA.2 would affect France and the UK in a similar way. And there, at least, the bottom line made sense. The BA.2 wave that rolled across the UK and France from February was relatively small compared to the BA.1 wave – in both countries.

France’s daily new BA.2 cases appear to be leveling off at a weekly average of 126,000 infections. The weekly average of daily new cases in the UK peaked at 125,000 on March 21. Deaths tend to delay cases by a few weeks so it’s not clear how deadly BA.2 will be in both countries, but so far the worst daily death toll is highly lower than BA.1.

Now consider Austria. With just 8.9 million inhabitants, it is smaller than Great Britain and France. But it is just as well vaccinated – and even came close to winning a nationwide vaccination mandate before canceling the proposed mandate in early March, days before it came into effect. Like most countries in Europe, Austria has ended domestic restrictions on business and travel.

But unlike Britain and France, Austria caught BA.2 worse as BA.1. BA.1 daily new case rates rose to a weekly average of 34,000 and stayed there for a month and a half. Then BA.2 arrived in early March, adding another 10,000 new cases daily, without much pause from BA.1, on top of the existing weekly average.

I don’t see a consistent red thread between the countries.

Apart from a tiny drop in mid-March, the daily death toll in Austria has been increasing every week since January. BA.2 claims an average of 40 lives a day, day after day.

Determining which measures make the difference is difficult – assuming differences in public health strategy matter at all against a virus as contagious as BA.2. Yes, Austria almost had a vaccination mandate, but it hasn’t actually come into force. And it is very difficult to say what impact the proposed mandate had or would have had.

“Even if no other people were vaccinated after a mandate was put in place, that doesn’t mean it didn’t ‘work’ as the purpose of the mandate may have been simply to ensure that the only people you meet when you’re in a restaurant or concert,” Maxwell Smith, a bioethicist at Western University in Ontario, told The Daily Beast.

A screen shows the number of new COVID-19 infections nationwide at a subway station March 17, 2022 in Seoul, South Korea.

Chung Sung Jun/Getty

“In this case, for the vaccination mandate to ‘work’ would mean reducing transmission rates of the virus in the environments to which it applies,” Smith added. “Or if critical infrastructure is preserved, it would mean something like fewer cases of serious illness or hospitalizations among elected officials.”

There are many ways Austria’s vaccination mandate could have improved outcomes for millions of Austrians at risk of contracting COVID. But that didn’t stop Austria from suffering worse from BA.2 than other neighboring countries.

“There are many factors that may have led to the case numbers that we’re seeing in both Austria and its neighboring countries, so I can’t say for sure that this is solely due to their vaccination policy or vaccination policy,” Smith said.

Experts are at a loss to explain what other factors might be at work. If neighboring countries have vaccinated roughly the same percentage of their populations and also reopened their borders, shops and schools – allowing for some degree of natural immunity from previous infections – then they should be equally prepared for a new strain of the virus.

Obviously they are not. “I don’t see a continuous red thread between the countries,” said Swartzberg.

There are serious implications for the rest of the world as they prepare for BA.2. Even strong vaccination intake and sustained natural immunity may not save you from a major wave of infection. By the same token, BA.2 could simply bypass a country for reasons no one fully understands, as was the case with South Africa.

But the experiences of whole countries are not the experiences of individuals. Yes, BA.2 could have unpredictable effects on the population. But science is clear about how people can reduce their personal risk. Favor well-ventilated indoor areas. Wear an N95 mask when local case numbers are high.

The most important thing is to get vaccinated and refreshed.

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