Just a few updates for this week:
- Scientists are still learning about BA.2, the more-transmissible Omicron offshoot. There haven’t been many major updates about BA.2 since last week, when I wrote this FAQ post; but this STAT News article by Andrew Joseph provides a helpful summary of what we know so far. The article explains that BA.2 clearly has a transmission advantage over BA.1 (and has now become the dominant variant in a few countries), but BA.1 may have spread around the world due to chance and some well-placed superspreading events. Notably, the CDC is not yet splitting out its Omicron prevalence estimates into BA.1 and BA.2, so we don’t have a great sense of how much this sub-lineage is spreading in the U.S.
- More data indicates immune system memory remains strong against Omicron. In previous Omicron update posts, I’ve noted that, while vaccinated people are more likely to have a breakthrough case with Omicron than with past variants, vaccination is still highly protective against severe symptoms. A new study published in Nature this week further affirms this protection; researchers found that 70% to 80% of T cell response to Omicron was retained in people who were vaccinated or tested positive on antibody tests, compared to past variants. (T cells are key pieces of immune system memory response.)
- Similarly, more data backs up the importance of vaccination to protect against severe disease during the Omicron era. The CDC released more MMWR studies this week showing that fully vaccinated and boosted Americans were less likely to require hospitalization or intensive care during the Omicron surge compared to the unvaccinated. For example, in Los Angeles County, California, hospitalization rates among unvaccinated people were 23 times higher than rates among those fully vaccinated with a booster, and five times higher than those vaccinated without a booster.
- Omicron is too transmissible for school testing programs to keep up. I’ve previously reported on the challenges of K-12 COVID-19 testing programs, including the difficulty of setting up public health logistics, getting enough tests, and increasing polarization of testing. During the Omicron surge, these challenges have been magnified—to the point that some states, including Utah, Vermont, and Massachusetts, have suspended testing programs, POLITICO reported this week. I hope to see some of these programs resume after the surge is over.
- The U.S.’s death toll during the Omicron surge has been far higher than in similarly wealthy nations. A new analysis from the New York Times compares the death toll in the U.S. from December 2021 through January 2022, adjusted for population, to death tolls in peer wealthy nations like Germany, Canada, Australia, and Japan. The comparison is striking: “the share of Americans who have been killed by the coronavirus is at least 63 percent higher than in any of these other large, wealthy nations,” the NYT reports. This difference is largely because the U.S. is less vaccinated than these other countries, particularly when it comes to booster shots and vaccinations among seniors.
- Globally, cases during the Omicron surge surpassed all of 2020. “In the 10 weeks since Omicron was discovered, there have been 90 million COVID-19 cases reported — more than in all of 2020,” said Tedros Adhanom Ghebreyesus, Director-General of the World Health Organization, at a press conference last week. In a Twitter thread reporting from the press conference, STAT’s Helen Branswell noted that the WHO is concerned about countries “opening up” and lifting COVID-19 restrictions before their case numbers are actually low enough to warrant these measures.
More variant reporting
More Omicron mutation in South Africa and the U.S.
As cases rise in the U.S. and other parts of the world, Omicron subvariants are a continued culprit. Experts are watching closely to see if further mutations of the virus may become even more contagious, or may gain the ability …
How one wastewater plant became a leading COVID-19 forecasting source
This week, I had a new story published with FiveThirtyEight and the Documenting COVID-19 project about the data and implementation challenges of wastewater surveillance. As bonus material in today’s COVID-19 Data Dispatch, I wanted to share one of the interviews …
National numbers, April 24
After weeks of me warning about it, a BA.2 surge is upon us. Nationwide, new COVID-19 cases have gone up for the third week in a row; we’ve seen a 68% increase since the last week of March.
Omicron keeps mutating as U.S. cases rise
As though it’s not already confusing enough to distinguish between Omicron BA.1 and BA.2, more sublineages have popped up in recent weeks as Omicron continues to spread and mutate. Here are two that I’m watching, though they don’t seem to …
The US still doesn’t have the data we need to make informed decisions on booster shots
Last fall, I wrote that the U.S. did not have the data we needed to make informed decisions about booster shots. Several months later, we still don’t have the data we need, as questions about a potential BA.2 wave and …
A BA.2 surge is approaching: Here’s what you should know about this variant
Europe's new surge is likely due to European leaders’ decisions to end all COVID-19 safety measures in their countries, combined with the rise of Omicron sublineage BA.2. As BA.2 prevalence increases here in the U.S.—and our leaders also end safety …