The delta variant hit the UK and India first. So here’s what we could expect

The coronavirus pandemic is still ongoing, and there has been a lot of talk about the coronavirus mutating into variants. Even more, there’s been some panic and concern about how those variants are going to put humanity at risk of more lockdowns, spikes and, yes, death.

But there may be a lot of data out there to help us understand how the delta variant will behave — and what the United States might expect next.

The delta variant has been spreading throughout the world. In fact, the delta variant made up 90% of COVID-19 cases earlier this summer in the United Kingdom, as I wrote for the Deseret News.

So what happened in the United Kingdom?

Well, recent data suggests that new confirmed cases of COVID-19 in the European Union and the United Kingdom experienced a massive spike at the beginning of the delta variant wave. However, soon after, cases dropped significantly due to high vaccinations and, it would appear, immunity gained from being infected.

Indeed, the daily confirmed COVID-19 cases dropped by 50% in the past week alone, according to Fortune.

Similarly, new deaths from COVID-19 followed a similar pattern. Those numbers climbed because of the delta variant and appeared to be flattening out.

“I don’t know how anyone can look at the U.K. cases and deaths and think that (banning a variant not here yet) there is any other scenario but going back to normal,” said economist Wojtek Kopczuk. “What we are observing is PTSD, but the reality that vaccines just work amazingly well will naturally take over.”

David Mackie, chief European economist for J.P. Morgan Securities, told Fortune it surprised him that the delta variant had such a collapse there. He said he is “reluctant to abandon the idea that the delta variant will be a problem over time.”

But, he told Fortune, “it is hard to argue against the idea that the current delta wave in the U.K. is turning out to be much, much milder than we anticipated.”

So let’s move to India

What happened in India, where the delta variant was originally discovered? Well, there was a second wave of coronavirus cases in India once the delta variant emerged, causing hundreds of thousands of cases throughout the country.

But cases declined significantly within a month or two. Daily cases were around 400,000 in May before dropping to about 40,000 in July. You can see from charts by Johns Hopkins University that cases spike in the early spring before dropping significantly as we headed toward summer. The drop-off from the delta spike was massive.

Now, there are a number of reasons for the dip. Per The Washington Post, experts said the sharp decline was because Indians decided to stay home to avoid the virus. Others suggest entire families were infected and hospitals were overwhelmed, so people did not leave their homes and, thus, did not infect people.

“Others attribute the falloff to the virus exhausting itself; it infected everyone it could,” according to The Washington Post.

The second wave from India is expected to hit the United States, experts told The Washington Post. In fact, you could argue we’re in the middle of that spike right now. But, if that holds true, then you could argue that the dip will be very real, too.

That said, some states in India are still suffering from COVID-19, and COVID-19 cases are going “in the wrong direction,” V.K. Paul, a senior health official, said, according to The Washington Post.

And though the peak isn’t as high, the delta variant is still in India. And it doesn’t help that millions there have not been vaccinated against COVID-19, experts said.

“Much of India is still vulnerable,” Ashish Jha, dean of the Brown University School of Public Health, told The Washington Post. “That’s what keeps me awake at night when I think about the coming weeks and months.”

What it all means

Still, there’s no question that the delta variant doesn’t have a sustained outbreak. From all this data, it’s clear the delta variant comes in, transmits quickly between people, causes a huge spike and then drops off. That’s been the pattern for the U.K. and India, two regions in the world comparable to the United States.

Andy Slavitt, a former adviser on U.S. President Joe Biden’s COVID-19 response team, said this might be the new normal for the U.S. as it experiences the delta wave.

“Delta takes a quick rise & a quick drop,” Slavitt wrote on Twitter. 

Indeed, Dr. Scott Gottlieb, a former Food and Drug Administration commissioner, said Sunday on CBS’ “Face the Nation” that the U.S. is often three to four weeks behind the United Kingdom when it comes to the COVID-19 pandemic and case numbers.

He said “hopefully we’re going to turn a corner” in the next week or so when it comes to the delta variant, based on that modeling.

“If you look at the U.K., they do in the last seven days appear to be turning a corner. You’re starting to see a downward trajectory on the cases. Now, it’s unclear whether that’s going to be sustained,” Gottlieb added.

Part of that is because the unvaccinated still remain at risk. Experts still recommend unvaccinated people get the COVID-19 vaccine to stay safe from any variant that emerges.

Right now, about 165.6 million people in the United States have been fully vaccinated against COVID-19, which is about 49.9%, according to the Centers for Disease Control and Prevention. The CDC numbers do lag a bit, which is why you’ve seen reports that 70% of people have gotten one dose of the vaccine.

Still, that’s about 30% of people who are still unsafe from COVID-19. So it’s still uncertain what lies ahead in the United States. We’ve seen the delta variant’s pattern elsewhere. But each country is different. Each situation is different. The United States has so many regions that make it difficult to predict what will happen.

That’s why modelers remain unsure about where the United States is in its delta wave. It’s possible the U.S. is still in the early days — and a huge spike of cases is going to continue — or of it is going to follow the U.K.’s sharp decline in the next few days or weeks.

“I’m really hoping that we get sort of that hairpin (shaped) drop off in infections,” Christina Ramirez, a biostatistics professor at the University of California, Los Angeles, told Fortune. “But this is really hard to model. For (statisticians) such as myself, this really makes us want to pull our hair out, because it’s really complicated.”