In the United States, polio is a memory, and a fading one at that. The last major outbreak here happened in 1952; the virus was declared eliminated in 1979. With all of that behind us, you can see how someone'say, Kirk Milhoan, the chair of the CDC's vaccine advisory committee'might wonder whether giving the polio vaccine to American kids still makes sense. 'We need to not be afraid to consider that we are in a different time now,' Milhoan said on the podcast Why Should I Trust You' last week. To be fair, Milhoan didn't endorse yanking the polio vaccine from the CDC's childhood-immunization schedule, as other vaccines were earlier this month. But he didn't rule it out. And right now, when it comes to vaccines in America, anything seems possible. With Robert F. Kennedy Jr. at the helm of the Department of Health and Human Services, and with the CDC's vaccine advisory committee stacked with his allies, every inoculation'no matter how well studied or successful'seems to be under new scrutiny, and at least potentially on the chopping block. Next on the committee's agenda is looking into the safety of aluminum salts, which are used in numerous vaccines to boost the recipient's immune response. For the record, a study of more than 1 million Danish children, published last July, found no statistically significant evidence linking aluminum in vaccines to asthma, autoimmune conditions, or neurodevelopmental disorders, including autism....

Last year, starting in January, the United States experienced its largest documented measles outbreak in more than three decades, when an epidemic centered on West Texas sickened at least 762 people. Now a fast-moving outbreak in South Carolina seems poised to surpass it: Local officials have logged 700 infections, and the virus is still rapidly spreading. As public-health officials scramble to contain the virus, they're also trying to figure out whether these two outbreaks are connected'specifically, whether the version of the pathogen that kick-started the West Texas cases has been circulating within the nation's borders ever since. If the answer is yes, it will mean that measles has once again become a permanent resident of this country, after 26 years of only limited outbreaks imported from abroad. Given that the U.S. clocked more than 2,200 measles cases in 2025'more than it has had in a single year since 1991'the experts I spoke with already consider this the reality that Americans are living in. One of the fastest-spreading viral diseases ever documented has once again become a routine threat....

When Lola was eight years old, she went through a massive growth spurt and started developing acne. Her mother, Elise, thought Lola was just growing fast because of genes inherited from her father. But when she noticed that Lola had grown pubic hair too, she was floored. A visit to an endocrinologist in 2023 confirmed that Lola's brain was already producing hormones that had kick-started puberty. Lola had also been struggling emotionally. 'She would have panic attacks every day at school,' says Elise, who lives in Minneapolis, Minnesota, and asked that her surname and Lola's real name be omitted. Although eight might seem young to start puberty, it's not as rare as it once was. Data show that girls around the world are entering puberty younger than before. In the 1840s, the average age of first menstruation, or menarche, was about 16 or 17; today, it's around 12. The average age for onset of breast development fell from 11 years in the 1960s to around 9 or 10 years in the United States by the 1990s. Some research hints that the trend mysteriously accelerated during the COVID-19 pandemic. (Although some data suggest that puberty is happening earlier for boys too, the shift seems to be less pronounced.)...

A team based at the University of Vienna put individual clusters of around 7,000 atoms of sodium metal some 8 nanometres wide into a superposition of different locations, each spaced 133 nanometres apart. Rather than shoot through the experimental set up like a billiard ball, each chunky cluster behaved like a wave, spreading out into a superposition of spatially distinct paths and then interfering to form a pattern researchers could detect. Quantum theory doesn't put a limit on how big a superposition can be, but everyday objects clearly do not behave in a quantum way, she explains. This experiment ' which puts an object as massive as a protein or small virus particle into a superposition ' is helping to answer the 'big, almost philosophical question of 'is there a transition between the quantum and classical''' she says. The authors 'show that, at least for clusters of this size, quantum mechanics is still valid'. The experiment, described in Nature on 21 January1, is of practical importance, too, says Giulia Rubino, a quantum physicist at the University of Bristol, UK. Quantum computers will ultimately need to maintain perhaps millions of objects in a large quantum state to perform useful calculations. If nature were to make systems collapse past a certain point, and that scale was smaller than what is needed to make a quantum computer,, 'then that's problematic,' she says....