‘Why Are We Not Vaccinating Children Under 12?’

An infectious-disease doctor on what we know about the Delta variant and the risks that lie ahead.

Illustration of a clock.
Getty ; The Atlantic

And just like that, it’s Groundhog Day. The news from the CDC is bad. Yes, we have vaccines—and they are miraculously effective at preventing serious illness and death from COVID-19. Thank goodness for that. But the CDC now says that when vaccinated people are infected, they may spread the coronavirus just as easily as the unvaccinated do. On top of that, the Delta variant is tremendously contagious, much more so than the original strain of the virus. As federal health officials put it in a document first obtained by The Washington Post, we must now “acknowledge the war has changed.”

To make sense of all this, I called Gary Simon, the Walter G. Ross Professor of Medicine and director of the Division of Infectious Diseases at George Washington University’s School of Medicine and Health Sciences. Our conversation has been lightly edited and condensed for clarity.


Adrienne LaFrance: The big development that’s so worrisome seems to be that the Delta variant is still highly transmissible among vaccinated people—meaning vaccinated people can carry a high viral load and infect the unvaccinated. Does this mean we should all go back to acting as if we’re unvaccinated, especially those who live with immunocompromised folks or unvaccinated ones, like little kids?

Gary Simon: I’m not wearing a mask unless I’m in a crowd where I don’t know people’s vaccination status. If I’m around only vaccinated people indoors, I’m not wearing a mask. Little kids who are exposed are potentially [at risk], but people are unlikely to wear masks at home around their children. Kids go to school. If they wear masks, the risk of transmission is probably small, but it’s not zero. So everybody’s going to have to have a judgment about that.

If you’re going to a restaurant, first, try to eat outside. Second, wear the mask until you sit down to eat. That’s the best we can do. Every second is going to be a judgment call. I’m going to go to the museum with my cousin today and we’re going to wear a mask through the museum. That’s what we’re doing.

LaFrance: The CDC says Delta is as contagious as chicken pox. What does that mean in the context of day-to-day decision making? We’re all used to masking and standing six feet apart, but is that good enough for Delta? What’s the best way to think about just how contagious this strain is?

Simon: Look, it is more contagious than early strains. And so think [about] how contagious that was. It’s at least twice as contagious, maybe three or four times as contagious. Six feet from an unvaccinated person is not protection anymore. I would wear masks. It is [as] contagious as chicken pox, which is highly contagious. It’s less contagious than measles, which is highly, highly contagious. It’s hard to quantitate.

Delta is about as highly contagious as anything except for measles. It’s not as contagious as measles, but measles is virtually 90 percent—meaning that when you came in contact with someone who had measles, you got it. That’s why we all got measles [before the measles vaccine].

LaFrance: Should we expect that the next variant will be more measles-like? Do we need to brace ourselves for a variant of COVID-19 that infects 90 percent of nonimmune people who encounter it?

Simon: A variant may evolve that gets less contagious too. The question is: Will more variants evolve that are more resistant to the current vaccine or less? There’s a reasonable likelihood that the virus gets worse because we have a lot of unvaccinated people. So, yes, there’s still a chance it could become like measles.

LaFrance: We’re seeing more reports of children hospitalized and on ventilators—and the CDC now says that unvaccinated kids are more at risk given that this variant causes more serious illness and spreads more easily. How concerned do you think we should be about Delta and young unvaccinated people?

Simon: Why are we not vaccinating children under 12? I’m very cynical about the FDA right now. Why aren’t these vaccines fully approved for kids? Too many people are looking at these clinical trials and using that to say the vaccine is still experimental. The data is out there. It’s long past time to approve this broadly.

LaFrance: For ages 5 and up?

Simon: Yes. And then the excuse that it’s still an experimental vaccine will disappear.

LaFrance: Well, not to mention it would be useful to protect all those kids.

Simon: Right, now you get to the kids. An 11-year-old, a 10-year-old should certainly be getting the vaccine. They’re not [eligible for the vaccines] yet? Nonsense. Physiologically, is a 10-year-old that different from a 12-year-old? No. Should we be immunizing children at six months? I don’t know that, but we ought to be doing a study real quick. That’s really necessary. We need to start vaccinating kids. What we really need to do for the children is to show that they get an immune response. We should start immunizing them the way we immunize them for measles, mumps, rubella, varicella. We can’t wait.

LaFrance: Clearly everyone who is old enough should get a vaccine, and we know that dosage or schedule will evolve—we’re likely to need third shots. Talk about the extent to which we need to be developing new vaccines to keep up with this evolving virus.

Simon: Yes, and we are developing new vaccines. The tech now with the mRNA vaccine allows you to tweak it very quickly. You don’t need a whole new conceptual vaccine. So, yes, there [could be] specific vaccines directed against Delta, against the Beta variety. And those are easily developed. Given the new technology, the technology developed by Moderna and Pfizer, you could rapidly make a change that’s effective against those. We have to have them available even if we decide not to use them. It doesn’t mean we mass-produce them yet. But at least we need to have the ability to start producing that new vaccine. I may be proved wrong, but I think we should be tweaking the mRNA platform in order to address these variants.

LaFrance: This is all very Groundhog Day. It now seems like the fall and winter of 2021 will be a repeat of last year. How badly are we losing to the virus right now?

Simon: It’s definitely going to be bleak, but I don’t think it’s going to be quite as bad as last winter. But we also don’t really know how much the vaccine protects against Delta.

LaFrance: Especially as immunity wanes, right?

Simon: Immunity will wane. I don’t see why a third shot is not approved right now. I see no logic to it. Perhaps they think Pfizer will make too much money. And so what? People will get it who don’t really need it. So what?! I would go tomorrow to get the third shot.

The Atlantic’s COVID-19 coverage is supported by grants from the Chan Zuckerberg Initiative and the Robert Wood Johnson Foundation.

Adrienne LaFrance is the executive editor of The Atlantic. She was previously a senior editor and staff writer at The Atlantic, and the editor of TheAtlantic.com.