For all the coronavirus variants that have thrown pandemic curve balls — including alpha, beta, gamma and delta — COVID-19 vaccines have stayed the same. That could change this fall.

On June 28, an advisory committee to the U.S. Food and Drug Administration met to discuss whether vaccine developers should update their jabs to include a portion of the omicron variant — the version of the coronavirus that currently dominates the globe. The verdict: The omicron variant is different enough that it’s time to change the vaccines. Those shots should be a dual mix that includes both a piece of the nearly identical omicron subvariants BA.4/BA.5 and the virus from the original vaccines, the FDA announced June 30.

“This doesn’t mean that we are saying that there will be boosters recommended for everyone in the fall,” Amanda Cohn, chief medical officer for vaccine policy at the U.S Centers for Disease Control and Prevention said at the meeting. “But my belief is that this gives us the right vaccine for preparation for boosters in the fall.”
The decision to update COVID-19 vaccines didn’t come out of nowhere. In the two-plus years that the coronavirus has been spreading around the world, it has had a few “updates” of its own — mutating some of its proteins that allow the virus to more effectively infect our cells or hide from our immune systems.

Vaccine developers had previously crafted vaccines to tackle the beta variant that was first identified in South Africa in late 2020. Those were scrapped after studies showed that current vaccines remained effective.

The current vaccines gave our immune systems the tools to recognize variants such as beta and alpha, which each had a handful of changes from the original SARS-CoV-2 virus that sparked the pandemic. But the omicron variant is a slipperier foe. Lots more viral mutations combined with our own waning immunity mean that once omicron can gain a foothold in the body, vaccine protection isn’t as good as it once was at fending off COVID-19 symptoms (SN: 6/27/22).

The shots still largely protect people from developing severe symptoms, but there has been an uptick in hospitalizations, especially among older people, Heather Scobie, deputy team lead of the CDC’s Surveillance and Analytics Epidemiology Task Force said at the meeting. Deaths among older age groups are also beginning to increase. And while it’s impossible to predict the future, we could be in for another tough fall and winter, epidemiologist Justin Lessler of the University of North Carolina at Chapel Hill said at the meeting. From March 2022 to March 2023, simulations project that deaths from COVID-19 in the United States might number in the tens to hundreds of thousands.

A switch to omicron-containing jabs may give people an extra layer of protection for the upcoming winter. Pfizer-BioNTech presented data at the meeting showing that updated versions of its mRNA shot gave clinical trial participants a boost of antibodies that recognize omicron. One version included omicron alone, while the other is a twofer, or bivalent, jab that mixes the original formulation with omicron. Moderna’s bivalent shot boosted antibodies too. Novavax, which developed a protein-based vaccine that the FDA is still mulling whether to authorize for emergency use, doesn’t have an omicron-based vaccine yet, though the company said its original shot gives people broad protection, generating antibodies that probably will recognize omicron.

Pfizer and Moderna both updated their vaccines using a version of omicron called BA.1, which was the dominant variant in the United States in December and January. But BA.1 has siblings and has already been outcompeted by some of them.
Since omicron first appeared late last year, “we’ve seen a relatively troubling, rapid evolution of SARS-CoV-2,” Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said at the advisory meeting.

Now, omicron subvariants BA.2, BA.2.12.1, BA.4 and BA.5 are the dominant versions in the United States and other countries. The CDC estimates that roughly half of new U.S. infections the week ending June 25 were caused by either BA.4 or BA.5. By the time the fall rolls around, yet another new version of omicron — or a different variant entirely — may join their ranks. The big question is which of these subvariants to include in the vaccines to give people the best protection possible.

BA.1, the version already in the updated vaccines, may be the right choice, virologist Kanta Subbarao said at the FDA advisory meeting. An advisory committee to the World Health Organization, which Subbarao chairs, recommended on June 17 that vaccines may need to be tweaked to include omicron, likely BA.1. “We’re not trying to match [what variants] may circulate,” Subbarao said. Instead, the goal is to make sure that the immune system is as prepared as possible to recognize a wide variety of variants, not just specific ones. The hope is that the broader the immune response, the better our bodies will be at fighting the virus off even as it evolves.

The variant that is farthest removed from the original virus is probably the best candidate to accomplish that goal, said Subbarao, who is director of the WHO’s Collaborating Center for Reference and Research on Influenza at the Doherty Institute in Melbourne, Australia. Computational analyses of how antibodies recognize different versions of the coronavirus suggest that BA.1 is probably the original coronavirus variant’s most distant sibling, she said.

Some members of the FDA advisory committee disagreed with choosing BA.1, instead saying that they’d prefer vaccines that include a portion of BA.4 or BA.5. With BA.1 largely gone, it may be better to follow the proverbial hockey puck where it’s going rather than where it’s been, said Bruce Gellin, chief of Global Public Health Strategy with the Rockefeller Foundation in Washington, D.C. Plus, BA.4 and BA.5 are also vastly different from the original variant. Both have identical spike proteins, which the virus uses to break into cells and the vaccines use to teach our bodies to recognize an infection. So when it comes to making vaccines, the two are somewhat interchangeable.
There are some real-world data suggesting that current vaccines offer the least amount of protection from BA.4 and BA.5 compared with other omicron subvariants, Marks said. Pfizer also presented data showing results from a test in mice of a bivalent jab with the original coronavirus strain plus BA.4/BA.5. The shot sparked a broad immune response that boosted antibodies against four omicron subvariants. It’s unclear what that means for people.

Not everyone on the FDA advisory committee agreed that an update now is necessary — two members voted against it. Pediatrician Henry Bernstein of Zucker School of Medicine at Hofstra/Northwell in Uniondale, N.Y., noted that the current vaccines are still effective against severe disease and that there aren’t enough data to show that any changes would boost vaccine effectiveness. Pediatric infectious disease specialist Paul Offit of Children’s Hospital of Philadelphia said that he agrees that vaccines should help people broaden their immune responses, but he’s not yet convinced omicron is the right variant for it.

Plenty of other open questions remain too. The FDA could have authorized either a vaccine that contains omicron alone or a bivalent shot. Some data presented at the meeting hinted that a bivalent dose might spark immunity that could be more durable, but that’s still unknown. Pfizer and Moderna tested their updated shots in adults. It’s unclear what the results mean for kids. Also unknown is whether people who have never been vaccinated against COVID-19 could eventually start with such an omicron-based vaccine instead of the original two doses.

Maybe researchers will get some answers before boosters start in the fall. But health agencies needed to make decisions now, so vaccine developers have a chance to make the shots in the first place. Unfortunately, we’re always lagging behind the virus, said pediatrician Hayley Gans of Stanford University. “We can’t always wait for the data to catch up.”

You might want to bring your dumbbells on that next spaceflight.

During space missions lasting six months or longer, astronauts can experience bone loss equivalent to two decades of aging. A year of recovery in Earth’s gravity rebuilds about half of that lost bone strength, researchers report June 30 in Scientific Reports.

Bones “are a living organ,” says Leigh Gabel, an exercise scientist at the University of Calgary in Canada. “They’re alive and active, and they’re constantly remodeling.” But without gravity, bones lose strength.
Gabel and her colleagues tracked 17 astronauts, 14 men and three women with the average age of 47, who spent from four to seven months in space. The team used high-resolution peripheral quantitative computed tomography, or HR-pQCT, which can measure 3-D bone microarchitecture on scales of 61 microns, finer than the thickness of human hair, to image the bone structure of the tibia in the lower leg and the radius in the lower arm. The team took these images at four points in time — before spaceflight, when the astronauts returned from space, and then six months and one year later — and used them to calculate bone strength and density.

Astronauts in space for less than six months were able to regain their preflight bone strength after a year back in Earth’s gravity. But those in space longer had permanent bone loss in their shinbones, or tibias, equivalent to a decade of aging. Their lower-arm bones, or radii, showed almost no loss, likely because these aren’t weight-bearing bones, says Gabel.

Increasing weight lifting exercises in space could help alleviate bone loss, says Steven Boyd, also a Calgary exercise scientist. “A whole bunch of struts and beams all held together give your bone its overall strength,” says Boyd. “Those struts or beams are what we lose in spaceflight.” Once these microscopic tissues called trabeculae are gone, you can’t rebuild them, but you can strengthen the remaining ones, he says. The researchers found the remaining bone thickened upon return to Earth’s gravity.
“With longer spaceflight, we can expect bigger bone loss and probably a bigger problem with recovery,” says physiologist Laurence Vico of the University of Saint-Étienne in France, who was not part of the study. That’s especially concerning given that a crewed future mission to, say, Mars would last at least two years (SN: 7/15/20). She adds that space agencies should also consider other bone health measures, such as nutrition, to reduce bone absorption and increase bone formation (SN: 3/8/05). “It’s probably a cocktail of countermeasure that we will have to find,” Vico says.

Gabel, Boyd and their colleagues hope to gain insight on how spending more than seven months in space affects bones. They are part of a planned NASA project to study the effects of a year in space on more than a dozen body systems. “We really hope that people hit a plateau, that they stop losing bone after a while,” says Boyd.

A flexible electronic implant could one day make pain management a lot more chill.

Created from materials that dissolve in the body, the device encircles nerves with an evaporative cooler. Implanted in rats, the cooler blocked pain signals from zipping up to the brain, bioengineer John Rogers and colleagues report in the July 1 Science.

Though far from ready for human use, a future version could potentially let “patients dial up or down the pain relief they need at any given moment,” says Rogers, of Northwestern University in Evanston, Ill.
Scientists already knew that low temperatures can numb nerves in the body. Think of frozen fingers in the winter, Rogers says. But mimicking this phenomenon with an electronic implant isn’t easy. Nerves are fragile, so scientists need something that gently hugs the tissues. And an ideal implant would be absorbed by the body, so doctors wouldn’t have to remove it.

Made from water-soluble materials, the team’s device features a soft cuff that wraps around a nerve like toilet paper on a roll. Tiny channels snake down its rubbery length. When liquid coolant that’s pumped through the channels evaporates, the process draws heat from the underlying nerve. A temperature sensor helps scientists hit the sweet spot — cold enough to block pain but not too cold to damage the nerve.

The researchers wrapped the implant around a nerve in rats and tested how they responded to having a paw poked. With the nerve cooler switched on, scientists could apply about seven times as much pressure as usual before the animals pulled their paws away. That’s a sign that the rats’ senses had grown sluggish, Rogers says.

He envisions the device being used to treat pain after surgery, rather than chronic pain. The cooler connects to an outside power source and would be tethered to patients like an IV line. They could control the level of pain relief by adjusting the coolant’s flow rate. Such a system might offer targeted relief without the downsides of addictive pain medications like opioids, Rogers suggests (SN: 8/27/19).

Now the researchers want to explore how long they can apply the cooling effect without damaging tissues, Rogers says. In experiments, the longest that they cooled rats’ nerves was for about 15 minutes.

“If treating pain, cooling would have to go on for a much longer period of time,” says Seward Rutkove, a nerve physiologist at Harvard Medical School who wasn’t involved in the study. Still, he adds, the device is “an interesting proof of concept and should definitely be pursued.”