Even a year into the pandemic, it’s not yet entirely clear why this is the case. Research points to a different immune response to viral exposure in children, which may signify that their immune systems are able to neutralize the virus much faster and therefore stop it from replicating. Children may also benefit from cross-protection by antibodies to other circulating coronaviruses that they are more regularly exposed to.
And there’s also the possibility that children have fewer ACE2 receptors in the cells that line nasal passages, which are the doorways the SARS-CoV-2 viruses uses to gain entry to host cells and infect them. That would make it less likely for the virus to get a foot in the door. There is a more serious complication of SARS-CoV-2 exposure that can occur in children, called multisystem inflammatory syndrome in children, or MIS-C. However it is rare, with fewer than 1,700 cases and just 26 deaths reported across the US.
Children’s apparent resilience to covid-19 makes them a lower priority for vaccination, especially when demand for vaccines far outstrips supply.
Children also are a challenge in vaccine development—and in any kind of drug development—because they are considered a vulnerable population, says Beth Thielen, a pediatric infectious disease specialist at the University of Minnesota. “We want to take extra safeguards to protect them from injury,” she says. “We tend to just be a lot more cautious about enrolling children in studies and not exposing them to undue risk.”
The prospect of the potential harm from trialing a new vaccine or drug in children outweighing the benefits is of particular concern when it comes to MIS-C, says Anna Sick-Samuels, a pediatrician in the Division of Infectious Diseases at the Johns Hopkins School of Medicine. MIS-C is thought to result from a massive inflammatory response to the SARS-CoV-2 virus. “It will be important to assess whether the current MRNA vaccines can lead to an antibody response that also triggers MIS-C or if this is only a complication of the viral infection,” she says.
It therefore seems likely that there will be a delay before children start getting vaccinated in large numbers. This means there may be a demographic shift in covid-19 infections as older sections of the population acquire immunity and the burden of infection shifts to the unvaccinated younger groups. It doesn’t mean more children will get the virus, but if fewer adults are at risk, children will be overrepresented in infection numbers relative to adults—the opposite of what is seen currently around the world.
It raises the possibility that delaying the immunization of children could make them a reservoir of the virus in the population, which could continue to seed further outbreaks. That could pose a problem even for vaccinated adults, says Mobeen Rathore, an infectious disease specialist and epidemiologist at the University of Florida College of Medicine.
The current approved vaccines offer a high level of protection against infection, but it’s not total protection. In the clinical trials, a small number of adults who were vaccinated still got infected, though they were far less likely to get seriously ill. There’s also no data yet on whether the vaccines prevent transmission from a vaccinated but infected person to another person—although research is now under way to find out if they do, and the early signs are promising.
“So the question really is: those people who are immunized, they get the infection—they’re not going to get sick, but you will not be able to stop the infection cycle,” Rathore says. And as long as the virus is circulating in the population, there’s the risk of disease, deaths, and mutations.
Earlier in the pandemic, it was thought that children were less likely to transmit SARS-CoV-2 to other children or to adults. A study of schools in England in June and July 2020, after they reopened following the first major lockdown, found relatively few infections or outbreaks. But further research, especially after the reopening of schools, universities, and colleges, suggests that infection rates are particularly high in young adults.
The evidence on transmission within and from younger age groups is conflicting, says Stefan Flasche, a vaccine epidemiologist at the London School of Hygiene and Tropical Medicine. It’s complicated by the fact that infected children are also less likely to show symptoms than infected adults, which makes them less likely to get tested for infection in the first place. “It seems like we’re in a situation where children can transmit, but they’re not sticking out as the key transmitter,” he says.
That could change once more adults are vaccinated and therefore less likely to get the disease. A similar development has already been seen in the UK, not as a result of vaccination but of more recent lockdown measures that restricted the movement of adults while schools stayed open. “In that setting, it looks like children were actually the residual source of transmission or a substantial contributor to the residual transmission,” Flasche says.
How do I know if egg freezing is for me?
The tool is currently being trialed in a group of research volunteers and is not yet widely available. But I’m hoping it represents a move toward more transparency and openness about the real costs and benefits of egg freezing. Yes, it is a remarkable technology that can help people become parents. But it might not be the best option for everyone.
Read more from Tech Review’s archive
Anna Louie Sussman had her eggs frozen in Italy and Spain because services in New York were too expensive. Luckily, there are specialized couriers ready to take frozen sex cells on international journeys, she wrote.
Michele Harrison was 41 when she froze 21 of her eggs. By the time she wanted to use them, two years later, only one was viable. Although she did have a baby, her case demonstrates that egg freezing is no guarantee of parenthood, wrote Bonnie Rochman.
What happens if someone dies with eggs in storage? Frozen eggs and sperm can still be used to create new life, but it’s tricky to work out who can make the decision, as I wrote in a previous edition of The Checkup.
Meanwhile, the race is on to create lab-made eggs and sperm. These cells, which might be made from a person’s blood or skin cells, could potentially solve a lot of fertility problems—should they ever prove safe, as I wrote in a feature for last year’s magazine issue on gender.
Researchers are also working on ways to mature eggs from transgender men in the lab, which could allow them to store and use their eggs without having to pause gender-affirming medical care or go through other potentially distressing procedures, as I wrote last year.
From around the web
The World Health Organization is set to decide whether covid still represents a “public health emergency of international concern.” It will probably decide to keep this status, because of the current outbreak in China. (STAT)
Researchers want to study the brains, genes, and other biological features of incarcerated people to find ways to stop them from reoffending. Others warn that this approach is based on shoddy science and racist ideas. (Undark)
A watermark for chatbots can expose text written by an AI
For example, since OpenAI’s chatbot ChatGPT was launched in November, students have already started cheating by using it to write essays for them. News website CNET has used ChatGPT to write articles, only to have to issue corrections amid accusations of plagiarism. Building the watermarking approach into such systems before they’re released could help address such problems.
In studies, these watermarks have already been used to identify AI-generated text with near certainty. Researchers at the University of Maryland, for example, were able to spot text created by Meta’s open-source language model, OPT-6.7B, using a detection algorithm they built. The work is described in a paper that’s yet to be peer-reviewed, and the code will be available for free around February 15.
AI language models work by predicting and generating one word at a time. After each word, the watermarking algorithm randomly divides the language model’s vocabulary into words on a “greenlist” and a “redlist” and then prompts the model to choose words on the greenlist.
The more greenlisted words in a passage, the more likely it is that the text was generated by a machine. Text written by a person tends to contain a more random mix of words. For example, for the word “beautiful,” the watermarking algorithm could classify the word “flower” as green and “orchid” as red. The AI model with the watermarking algorithm would be more likely to use the word “flower” than “orchid,” explains Tom Goldstein, an assistant professor at the University of Maryland, who was involved in the research.
The Download: watermarking AI text, and freezing eggs
That’s why the team behind a new decision-making tool hope it will help to clear up some of the misconceptions around the procedure—and give would-be parents a much-needed insight into its real costs, benefits, and potential pitfalls. Read the full story.
This story is from The Checkup, MIT Technology Review’s weekly newsletter giving you the inside track on all things health and biotech. Sign up to receive it in your inbox every Thursday.
I’ve combed the internet to find you today’s most fun/important/scary/fascinating stories about technology.
1 Elon Musk held a surprise meeting with US political leaders
Allegedly in the interest of ensuring Twitter is “fair to both parties.” (Insider $)
+ Kanye West’s presidential campaign advisors have been booted off Twitter. (Rolling Stone $)
+ Twitter’s trust and safety head is Musk’s biggest champion. (Bloomberg $)
2 We’re treating covid like flu now
Annual covid shots are the next logical step. (The Atlantic $)
3 The worst thing about Sam Bankman-Fried’s spell in jail?
Being cut off from the internet. (Forbes $)
+ Most crypto criminals use just five exchanges. (Wired $)
+ Collapsed crypto firmFTX has objected to a new investigation request. (Reuters)
4 Israel’s tech sector is rising up against its government
Tech workers fear its hardline policies will harm startups. (FT $)
5 It’s possible to power the world solely using renewable energy
At least, according to Stanford academic Mark Jacobson. (The Guardian)
+ Tech bros love the environment these days. (Slate $)
+ How new versions of solar, wind, and batteries could help the grid. (MIT Technology Review)
6 Generative AI is wildly expensive to run
And that’s why promising startups like OpenAI need to hitch their wagons to the likes of Microsoft. (Bloomberg $)
+ How Microsoft benefits from the ChatGPT hype. (Vox)
+ BuzzFeed is planning to make quizzes supercharged by OpenAI. (WSJ $)
+ Generative AI is changing everything. But what’s left when the hype is gone? (MIT Technology Review)
7 It’s hard not to blame self-driving cars for accidents
Even when it’s not technically their fault. (WSJ $)
8 What it’s like to swap Google for TikTok
It’s great for food suggestions and hacks, but hopeless for anything work-related. (Wired $)
+ The platform really wants to stay operational in the US. (Vox)
+ TikTok is mired in an eyelash controversy. (Rolling Stone $)
9 CRISPR gene editing kits are available to buy online
But there’s no guarantee these experiments will actually work. (Motherboard)
+ Next up for CRISPR: Gene editing for the masses? (MIT Technology Review)
10 Tech workers are livestreaming their layoffs
It’s a candid window into how these notoriously secretive companies treat their staff. (The Information $)