Their shots, delivered as two 25-microgram doses spaced four weeks apart, produced a similar immune response in young children as two larger doses did in adults. In a 6,700-participant randomized trial the vaccines triggered no safety concerns such as myocarditis or multisystem inflammatory syndrome, the company said in a .

鈥淲e now have clinical data on the performance of our vaccine from infants six months of age through older adults,” said Moderna CEO St茅phane Bancel. “Given the need for a vaccine against COVID-19 in infants and young children we are working with the U.S. FDA and regulators globally to submit these data as soon as possible.鈥�

The update offers a glimmer of hope to many parents frustrated that their young children remain ineligible for immunizations more than two years into the pandemic, and who expressed dismay following a dramatic reversal last month from Pfizer-BioNTech, which withdrew its request for FDA approval of shots for children under 5 just days after submission.聽

鈥淎s an [infectious disease] doc and dad, I鈥檝e been eagerly awaiting these data for 15 months now 鈥� sounds like we鈥檒l see them soon. Fingers firmly crossed,鈥� Roby Battacharyya on Twitter.

Trial data show shots were 43.7% and 37.5% effective in preventing illness among children 6 months to 2 years old and 2 years to under 6 years old, respectively. No immunized children in the study suffered severe disease or death, but neither did any youngsters in the control group who received no vaccine doses.聽

Jacqueline Miller, Moderna鈥檚 senior vice president for infectious diseases, hypothesized that the lower efficacy reflected the Omicron variant鈥檚 ability to evade immune defenses. Regardless, she said, the shots convey a level of protection.

鈥淲hat I will say is 37.5% and 43.7% are higher than zero,鈥�, . 鈥淚f I were the parent of a young child, I would want there to be some protection on board, especially if we see another wave of infections.鈥�

The news comes as school mask mandates continue to drop across the country. Some 92% of the largest 500 school districts did not require face coverings as of March 23 compared to only 58% at the beginning of the month and 35% at the beginning of February, according to the .

On Tuesday, New York City Mayor Eric Adams announced that on April 4 the nation鈥檚 largest school district will be dropping its mask rule for toddlers 2- to 4-years old, which had stayed in place even after the city lifted its K-12 mandate.

Meanwhile, COVID cases in Europe are , fueled by the more transmissible Omicron subvariant BA.2. Even as infections continue to , many experts warn that the increases across the pond could foreshadow a coming wave in America.

As of March 16, 27% of children 5- to 11-year old and 57% of children 12- to 17-years old had completed their two-dose vaccine series, according to the .

鈥淏abies have physics on their side,鈥� researcher Danyang Han says with a laugh. Han鈥檚 recent paper, 鈥�,鈥� coauthored with Dr. Karen Adolph, looks at the role of babies鈥� missteps as they learn to walk. The researchers hypothesized that understanding babies鈥� falling could provide a window into the role that errors play in how babies acquire basic skills 鈥� useful information not only for researchers wanting to know more about babies, but for scientists and engineers looking for the best way to approach machine learning and artificial intelligence.

鈥淏abies natural way of falling protects them from serious injuries. Their bodies are close to the ground; they鈥檙e moving slowly and they鈥檙e very light weight,鈥� Han says. 鈥淪o, they don鈥檛 hit the ground very hard 鈥� and when they do, their bodies are 30% baby fat, and their bones are really strong. If an adult had 30% body fat, that would be obesity, but for babies, that鈥檚 padding.鈥�

Like junior judo masters, babies naturally engage in the art of ukemi, breaking falls by absorbing the impact throughout the body. Babies automatically engage in a suite of reactive behaviors when they begin to fall 鈥� taking small steps to regain balance, grabbing for any nearby support to slow down the speed of the fall, bending their knees and reaching out with their hands to break the fall or landing on their bottoms if they鈥檙e falling backward. Nobody teaches them this and they don鈥檛 have to think about it. When they first start walking, and therefore falling, that knowledge is instantly present.

The same physics that render babies鈥� falls inconsequential are precisely those that can make falls so devastating for older people who take a spill. Elderly people are not so low to the ground; they have greater body mass, their bones are brittle and when they reach out to break their fall, it鈥檚 frequently their wrists or hips that break instead.

In fact, it was a fellow researcher鈥檚 documentation of elderly people鈥檚 falls that led Adolph to consider much more detailed data on infants鈥� falling. NYU鈥檚 Julius Silver Professor of Psychology and Neural Science, Adolph has studied infants鈥� movement for 30 years. She had always made note of falls as part of her apparatus and walking studies. When Canadian researcher Dr. Stephen Robinovitch, a world expert on falls among the elderly, spent a sabbatical in her lab and she saw the massive amount of data he had collected from falls in hundreds of older people in nursing homes, she realized that she already had a trove of data that could be analyzed to deepen researchers鈥� understanding of babies鈥� falls.

Deploying the tools of NYU鈥檚 high-tech Infant Action Lab, Adolph began to take a deeper dive into every aspect of infants鈥� falling. For the study for that formed the basis for Han and Adolph鈥檚 鈥淔all Like a Baby鈥� paper, 138 families recruited from the New York City area brought their walking infants aged 13, 15 and 19 months to the lab, where they were observed for 20 minutes of spontaneous activity in a large playroom. (Details of the study can be found in Han鈥檚 and Adolph鈥檚 , which is available to the public.) None of the falls in the laboratory resulted in injury and severity was gauged by whether infants fussed, whether caregivers showed concern, and how long it took infants to recover and return to play. Researchers recorded 563 spontaneous falls during the course of the study. The babies fussed only 4.26% of the time, and caregivers expressed concern in only 7.64% of the babies falls.

鈥淎 lot of the parents鈥� language was about encouragement,鈥� Han says. 鈥溾�橸ou鈥檙e fine. It鈥檚 fine. There鈥檚 a ball, can you go get the ball?鈥� And a lot of it was advice, 鈥極ops. You fell. You gotta be careful with those stairs, love.鈥� But mostly, the babies just fell and got back up again.鈥�

An undeniably adorable of this persistence can be found in the study鈥檚 video, 鈥�15 Falls with the Stroller,鈥� which can be viewed on the NYU Databrary site. In it, a toddler is pushing a pink doll stroller. She falls, she gets up, she falls, she gets up, she falls, she gets up 鈥� 15 times in 20 minutes. Even when she falls and bumps her head, she fusses briefly, is comforted by her mom and then within seconds, enough of that and she鈥檚 back to that pink stroller. This little person is totally goal oriented and in it for the locomotion.

And mostly, that鈥檚 how falling is for babies. It鈥檚 trivial.

However, Adolph stresses, falling itself isn鈥檛 trivial for babies. In fact, it鈥檚 a leading cause of accidental injury and death in little babies.

鈥淭hat鈥檚 why you have to keep your windows shut and block the stairs when they鈥檙e learning to crawl and walk,鈥� she says. 鈥淭hey don鈥檛 understand what a bad fall can be.鈥�

What babies don鈥檛 do is stop and consider that they just fell and maybe they鈥檇 better not try that again. Because the consequence of their falls is no big deal, they don鈥檛 even pause. Even babies whose parents reported significant falls before the study showed no inhibition about just going for it 鈥� toddle, toddle, tumble, toddle. Language learning in infants is the same process, Adolph says. Making 鈥渕istakes鈥� while they鈥檙e learning to talk doesn鈥檛 even slow them down, as anyone within earshot of a babbling 1-year-old can attest.

Based on their research, Han and Adolph assert that babies learn basic skills like walking and talking by relying primarily on positive feedback when they accomplish their goals and discounting errors so that mistakes barely figure into the equation. What they don鈥檛 say is that all learning takes place this way. As we get older and our body of knowledge and needed skills become more complex and challenging, our errors are more costly and have more impact. 鈥淥h well,鈥� is not an adequate response to mistakes made learning to drive a car or climb a mountain.

But from a systems standpoint, the model of baby learning might offer an alternative to the reinforcement learning model for decision-making, which Microsoft describes, in part, as 鈥渁lgorithms and systems for technology that learns from its own successes (and failures).鈥� If machine learning were to follow a model truly patterned after human learning, the model would be heavily weighted toward positive rewards and negative feedback would be inconsequential. Researchers in Adolph鈥檚 lab have run such a study with simulated robots and found that with machine learning as with infant learning, no penalty for mistakes is the best approach for getting flexible, generative learning and building more capacity to transfer learning to new situations.

The NYU researchers are now collaborating with a group of computer scientists and robotics engineers at Oregon State University on a project inspired by their work on infant falling. The reinforcement learning model that penalizes errors is ubiquitous in machine learning and artificial intelligence (AI), so the no-harm, no-foul model of the Infant Action Lab researchers might encounter resistance. But one of these days, who knows? Maybe robots and AI of the future will learn to fail like a baby.