Tanya Lewis: Hi, and welcome to COVID, Quickly, a Scientific American podcast series.
Josh Fischman: This is your fast-track update on the COVID pandemic. We will bring you up-to-date on the science behind the most pressing questions about the virus. We help you understand the science behind the disease and dispel myths about research.
Lewis: I’m Tanya Lewis.
Fischman: I’m Josh Fischman.
Lewis: And we’re Scientific American‘s senior health editors. Today: Vaccines for the youngest children may be on their way!
Fischman: And new evidence about long COVID shows who gets it most often, and what the most common symptoms are.
It’s been nearly a year and a half since COVID vaccines were authorized for adults in the U.S. Even though COVID vaccines were approved for adults in the U.S., it’s been almost a year and a half since they were first approved for children under five. Could this be changing?
Lewis: Possibly. I understand why parents are frustrated. Parents have been assured for months that a vaccine was on the horizon. There have been some promising developments.
Like what? Are there good results?
Fischman: Just a couple of weeks ago, vaccine-maker Moderna announced it was filing for emergency use authorization for its vaccine for kids ages six months to six years. And Pfizer recently announced in a press release that its vaccine was 80 percent effective at preventing symptomatic COVID in kids under five, although they haven’t made the data public yet.
Does that get us any closer to getting a green light from the FDA?
Lewis: SciAm contributor Charlie Schmidt asked experts about when we can expect a vaccine for the littlest ones, what the reasons are for the holdup, and more. The FDA’s vaccine advisory committee is scheduled to meet June 8th, 21st and 22nd to discuss making younger children eligible.
Fischman: Did Charlie get any inkling of what might happen at these meetings?
Lewis: He spoke with Arnold Monto, acting chair of the advisory committee and an epidemiologist at the University of Michigan School of Public Health. Monto stated that the FDA could issue an EUA to children within a day or so of these meetings but that there are no guarantees. He also spoke with Arnold Monto, acting chair of the advisory committee and an epidemiologist at the University of Michigan School for Public Health.
Fischman: Why not just authorize it for all the kids?
Lewis: Well, the FDA has a very high bar for approving new vaccines or other biological products for children. Children already have a low risk of developing COVID-related complications, so companies must prove that their vaccines are safe for them.
Fischman: So far, they haven’t seen any serious safety issues, have they?
Lewis: No, most of the side effects have been mild and similar to those seen in older kids or adults. Side effects such as fever and seizures in young children and babies can be caused by mRNA vaccines. Moderna and Pfizer were able to generate strong immune responses even at low doses, which reduces the risk. Myocarditis, a rare form of heart inflammation, has not been seen in any cases. This is mostly a problem with boys.
Fischman: So the vaccines appear to be safe. That’s good. But how effective are they?
Lewis: That’s a great question. The vaccine’s immune response, or the amount of neutralizing antibodies produced by people who have been given it, is a large part of the initial data. These levels can be compared to those in older children or adults who were protected against COVID. This will allow you to extrapolate the protection to young children. This is called immunobridging.
Fischman: So that’s looking at parts of the immune system and how they behave. What about the real world effects? What about the real world effects? Did vaccines reduce childhood infection rates?
Lewis: For actual efficacy data, Pfizer has only announced data on about 1,700 kids, showing an efficacy rate for three doses of 80.3 percent. Moderna reported a lower efficacy rate of 37 to 51 percent for its two dose vaccine in kids under six. It remains to be seen if this will pass the FDA’s standards.
Fischman: Ok, interesting. This is a huge spread in efficacy. Is the FDA awaiting Pfizer’s data to evaluate Moderna?
Lewis: That’s been a point of contention. Politico reported that the agency had delayed reviewing Moderna’s submission until Pfizer was in. On his podcast “In the Bubble”, Robert Califf, the FDA Commissioner, stated to Andy Slavitt that there was no reason for the FDA not to review the submission. Pfizer expects to submit data by June’s FDA advisory committee meeting. They may then end up reviewing Moderna’s and Pfizer’s data simultaneously.
Fischman: And, like lots of worried parents, we’ll be watching that closely.
Lewis: It’s becoming clear that acute COVID isn’t the only consequence of the disease. Long-term COVID, which can cause symptoms to drag on, is a serious problem. Two new reports shed light on the causes and how it manifests.
Fischman: There’s still no strict definition of long COVID, Tanya. But estimates are that between 10 to 30 percent of infected people will have at least one symptom, a real disabling problem, that afflicts them at least a month after they’ve cleared the virus, and sometimes for half a year. They may have multiple symptoms.
Lewis: I saw a new CDC report that said one out of five infected people could develop long COVID. What are the most common problems?
Fischman: According to a new study, what affects people most often is serious fatigue, the kind that exhausts you after walking from one room in your house to another. You may also experience difficulty catching your breath, loss in smell, headaches and memory problems. There’s also difficulty concentrating, what people often call “brain fog.”
This list comes from new research in the Annals of Internal Medicine, and it’s the first report from a long-term study being done by the National Institutes of Health. All of these people were tested positive for the virus 6 weeks later.
Lewis: Are a lot of these people older, because age seems to make people more vulnerable to COVID?
Fischman: Advanced age actually doesn’t seem to be a big risk factor, Tanya. In fact, people aged 39-50 are most likely to be diagnosed with post-COVID conditions. That comes from a huge analysis of private health insurance claims, done on more than 78,000 people, collected by a nonprofit group called FAIR Health.
Lewis: They did find that women were more likely than men to have long-lasting problems, didn’t they? About 60 percent compared with about 40 percent?
Fischman: Yes, they did. Another important finding was that severe diseases weren’t a risk factor. Three quarters of these people had never been admitted to hospital. You can have a mild case but still be suffering months later.
Lewis: One of the problems long COVID patients have is that this isn’t an easy condition to diagnose. Is there any more information?
Fischman: The study confirmed that difficulty. The NIH team tested people through blood tests, heart tests and lung tests. They didn’t find any abnormalities.
That means the condition is real, but the tests aren’t good enough. This is a warning to doctors to not dismiss patients or say “it’s in my head” or any other similar phrase. Because this pandemic is continuing to grow, physicians need to be able to find treatment options.
Lewis: Now you’re up to speed. We appreciate you joining us. Tulika Bose and Jeff DelViscio edited our show.
Fischman: Come back in two weeks for the next episode of COVID, Quickly! And check out SciAm.com for updated and in-depth COVID news.
[The above text is a transcript of this podcast.]