Why did the CDC change course on masks?

In today’s newsletter, adapting to an evolving pandemic; catching a peek of Mars’s core; checking out tonight’s meteor showers; and tracking space hurricanes. Plus, here’s how squid help us figure out our brains.

This article is an adaptation of our weekly Science newsletter that was originally sent out on July 28, 2021. Want this in your inbox? Sign up here.

By Victoria Jaggard, SCIENCE executive editor

My husband is a cautious person, so it came as no surprise to me when he adapted to COVID-19 restrictions like a duckling to water. He still sets aside the mail in a “quarantine zone” next to the door, washes his hands immediately after being outside, and eats only at restaurants that have outdoor seating. What did shock me was the time last week when we headed to the grocery store and—for the first time in over a year—he had forgotten his mask.

He and I were early adopters of the COVID-19 vaccine, getting our jabs as soon as they came available. It was so encouraging to see cases drop as vaccines rolled out nationwide, and we went into the start of summer feeling like there was, at last, an end in sight. The Centers for Disease Control and Prevention must have been even more optimistic, declaring in May that fully vaccinated people no longer had to wear masks indoors. (Above, vaccinating in Rhode Island.)

But that was before the rise of the highly transmissible Delta variant. As our Michael Greshko and Maya Wei-Haas write, the CDC had to reverse course this week as data came in showing that vaccinated people are just as likely to spread the virus even if they don’t get sick from it. Now, the CDC says, even vaccinated people should wear masks inside in places with significant transmission—which is a lot more places than you might expect. It is worrisome that only 49 percent of the population is vaccinated, and transmission is considered high by the CDC in nearly half of all U.S. counties. (Pictured below, masked and unmasked in California.)

The more contagious variants also have scientists grappling with murky data on whether vaccinated people will need a third booster shot of the mRNA vaccines. Both the CDC and the Food and Drug Administration say they do not recommend booster shots based on the available evidence, and doctors shouldn’t administer extra doses beyond those authorized by the FDA. Still, some health officials are pointing to studies purporting to show levels of neutralizing antibodies declining among people who received the Pfizer vaccine. As Amy McKeever writes for us, antibodies aren’t everything, and other studies suggest that protection from the Pfizer shot should last for years. Experts also told us that booster shots aren’t really the best way to deal with the threat of variants. The White House expects regular FDA approval for the COVID-19 vaccines as soon as late August, which will spur businesses to require vaccination of employees.

“The best way to do that is to get everybody vaccinated once rather than finessing the potential incremental benefit you might from a booster vaccine in one group when you have a whole other group of people who aren’t vaccinated at all,” says Jane O’Halloran of Washington University School of Medicine in St. Louis. (This all applies to healthy, fully vaccinated people; the situation is more complex for people with compromised immune systems, who may indeed benefit from a booster dose.)

I don’t envy the scientists and health officials who have to sift through the constantly changing data, looking at sample sizes and methods and trying to parse the best course of action for the entire nation. I may not need a booster yet, but for my part, I will continue to embrace caution as the best line of defense, and my family will be wearing masks at the grocery store for the foreseeable future.

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Peek inside Mars: Researchers have analyzed the interior of Mars for the first time, including its shockingly large liquid core. The latest discovery for NASA’s InSight lander will help scientists determine how the dusty planet became what it is today, Nat Geo reports.

Key hour-by-hour information used by firefighters to track wildfires may be off-limits after September, the Los Angeles Times reports. The Pentagon has not responded to California officials who are requesting an extension of Pentagon satellite information used in the Fireguard program. U.S. Representative Adam Schiff is pressing the Pentagon to do so as well. The information falls outside the traditional international fighting scope of the U.S. military.

Lucky Americans: In other lands, people don't take the availability of vaccinations for granted. In Indonesia, where caseloads are still rising from COVID-19, people rush to get limited access to vaccines, Sydney Combs writes. The nation of 270 million is talking about a "lost generation” to the pandemic, Combs writes.

Beyond Bourdain: Some critics thought it was creepy to hear an AI version of Anthony Bourdain’s voice “talk” three lines of words by the late chef and travel writer in a recent documentary. Apparently, you now can design a chatbot to talk like a dead person. The purpose is to help loved ones of the deceased through their grief, the San Francisco Chronicle reports. But how far back can scientists re-create a voice? Last year, Nat Geo’s Debra Adams Simmons wrote on how science brought back the voice of an Egyptian priest from 3,000 years ago.


Another pandemic effect: Patrycja Donaburska, already undergoing psychiatric treatment and therapy, has seen her mental health decline during the pandemic. “Her anorexia worsened, panic attacks on public transport returned, and she had panic attacks at home, which she had never had before,” writes photographer Anna Liminowicz, working on a project on mental health in Poland. Experts say the pandemic’s effects on mental health may outlast the physical effects.


Anna Liminowicz’s photography is funded in part by National Geographic Society’s COVID-19 Emergency Fund for Journalists. If you would like to support storytelling like this, learn more here.


‘Space hurricane’: We’re talking about a gigantic funnel of plasma up to 1,700 miles across and 31,000 miles high. The only place these “hurricanes” have been spotted is above Earth, Robin George Andrews and Jason Treat write in the August issue of National Geographic. Of a 2014 “hurricane,” illustrated above, they write: “The weak solar wind, combined with the alignment of the north magnetic poles of the sun and Earth, constricted a normally expansive swath of northern lights into a tight, rotating spot above magnetic north.”



Meteor shower: Get ready for cosmic fireworks. The Delta Aquarid meteor shower peaks tonight through Friday night, with about 15 to 20 shooting stars per hour. Viewing is best in southern latitudes of the Northern Hemisphere, as well as the Southern Hemisphere. Best visibility may be before midnight, before the waning gibbous moon rises. The meteors seem to radiate from the constellation Aquarius. The show is an excellent pre-gamer to the iconic August Perseid meteor showers.




On Thursday, Rachael Bale writes on the latest on animals and wildlife. If you’re not a subscriber, sign up here to also George Stone on travel, Whitney Johnson on photography, Debra Adams Simmons on history, Rob Kunzig on the environment, and Rachel Buchholz on family and kids.


Squid-tastic: From the waters off Cape Cod, these squid have helped scientists shed light on everything from the basics of nerve signaling to the evolution of complex brains—and may help improve therapies for neurological disorders. (Above, photographer and Nat Geo Explorer Brian J. Skerry captures the image of hundreds of longfin inshore squid gathering off the Massachusetts coast to spawn each spring.)


This newsletter has been curated and edited by David Beard and Monica Williams, and Jen Tse has selected the photos. Have an idea, a link, an opinion on squid? We'd love to hear from you at david.beard@natgeo.com. Thanks for reading.

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