The Delta variant is taking over the world

The Delta variant is now dominant in the U.S., but our high vaccination rates still put us in a much better position than the rest of the world—which is facing the super-contagious variant largely unprotected.

Let’s look at how the U.S.’s situation compares:

U.S.: Delta now causes 52% of new cases, according to the latest Nowcast estimate from the CDC. (This estimate is pegged to July 3, so we can assume the true number is higher now.) It has outcompeted other concerning variants here, including Alpha/B.1.1.7 (now at 29%), Gamma/P.1 (now at 9%), and the New York City and California variants (all well under 5%). And Delta has taken hold in unvaccinated parts of the country, especially the Midwest and Mountain West.

Israel and the U.K.: Both of these countries—lauded for their successful vaccination campaigns—are seeing Delta spikes. Research from Israel has shown that, while the mRNA vaccines are still very good at protecting against Delta-caused severe COVID-19, these vaccines are not as effective against Delta-caused infection. As a result, public health experts who previously said that 70% vaccination could confer herd immunity are now calling for higher goals.

Japan: The Tokyo Olympics will no longer allow spectators after Japan declared a state of emergency. The country is seeing another spike in infections connected to the Delta variant, and just over a quarter of the population has received a dose of a COVID-19 vaccine. I argued in a recent CDD issue that, if spectators are allowed, the Olympics could turn into a superspreading event.

Australia: Several major cities are on lockdown in the face of a new, Delta-caused surge following a party where every single unvaccinated attendee was infected. Unlike other large countries that faced significant outbreaks, Australia has successfully used lockdowns to keep COVID-19 out: the country has under 1,000 deaths total. But the lockdown strategy has diminished incentives for Australians to get vaccinated; under 5% of the population has received a shot. Will lockdowns work against Delta, or does Australia need more shots now?

India: Delta was first identified in India, tied to a massive surge in the country earlier this spring. Now, India has also become the site of a Delta mutation, unofficially called “Delta Plus.” This new variant has an extra spike protein mutation; it may be even more transmissible and even better at invading people’s immune systems than the original Delta, though scientists are still investigating. India continues to see tens of thousands of new cases every day.

Africa: Across this continent, countries are seeing their highest case numbers yet; more than 20 countries are experiencing third waves. Most African countries have fewer genetic sequencing resources than the U.S. and other wealthier nations, but the data we do have are shocking: former CDC Director Dr. Tom Frieden reported that, in Uganda, Delta was detected in 97% of case samples. Meanwhile, vaccine delivery to these countries is behind schedule—Nature reports that many people in African countries and other low-income nations will not get their shots until 2023

South America: This continent is also under-vaccinated, and is facing threats from Delta as well as Lambda, a variant detected in Peru last year. While Lambda is not as fast-spreading as other variants, it has become the dominant variant in Peru and has been identified in at least 29 other countries. Peru has the highest COVID-19 death rate in the world, and scientists are concerned that Lambda may be more fatal than other variants. Studies on this variant are currently underway.

In short: basically every region of the world right now is seeing COVID-19 spikes caused by Delta. More than 20 countries are experiencing exponential case growth, according to the WHO:

We’ve already seen more COVID-19 deaths worldwide so far in 2021 than in the entirety of 2020. Without more widespread vaccination, treatments, and testing, the numbers will only get worse.

More international reporting

  • Russia’s invasion of Ukraine has COVID-19 impacts
    When Russian troops began attacking Ukraine, the country was just recovering from its worst COVID-19 surge of the pandemic. To state the terrifying obvious: war makes it much harder to control a pandemic.
  • We failed to vaccinate the world in 2021; will 2022 be more successful?
    In January, COVAX set a goal that many global health advocates considered modest: delivering 2.3 billion vaccine doses to low- and middle-income countries by the end of 2021. is saying it’ll deliver just 800 million vaccine doses by the end of 2021, according to the Washington Post, and only about 600 million had been delivered by early December.
  • Omicron variant: What we know, what we don’t, and why not to panic (yet)
    On Thanksgiving, my Twitter feed was dominated not by food photos, but by news of a novel coronavirus variant identified in South Africa earlier this week. While the variant—now called Omicron, or B.1.1.529—likely didn’t originate in South Africa, data from the country’s comprehensive surveillance system provided enough evidence to suggest that this variant could be more contagious than Delta, as well as potentially more able to evade human immune systems.
  • First COVID-19 antiviral pill gains authorization
    This week, an antiviral pill for COVID-19 was authorized in the U.K. The drug, made by American pharmaceutical company Merck, is the first COVID-19 treatment in pill form to gain approval by any regulatory agency.
  • Unpacking Delta AY.4.2: Are we prepared for the next variant?
    Recently, a new offshoot of the Delta variant has been gaining ground in the U.K. It’s called AY.4.2, and it appears to be slightly more transmissible than Delta itself. While experts say this variant doesn’t differ enough from Delta to pose a serious concern, I think it’s worth exploring what we know about it so far—and what this means for the future of coronavirus mutation.

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