Six Questions about the Kids' COVID Vaccine, Answered by an Infectious Disease Doctor
I enthusiastically support the vaccination against COVID for children aged 5-11 years old. As an infectious disease doctor who took care of hundreds of COVID-19 patients over the past 20 months, I have seen the immediate and long-term consequences of COVID-19 on patients – and on their families. As a father of two daughters, I have lived through the fear and anxiety of protecting my kids at all cost from the scourges of the pandemic and worried constantly about bringing the virus home from work.
It is imperative that we vaccinate as many children in the community as possible. There are several reasons why. First children do get sick from COVID-19. Over the course of the pandemic in the U.S, more than 2 million children aged 5-11 have become infected, more than 8000 have been hospitalized, and more than 100 have died, making COVID one of the top 10 causes of pediatric deaths in this age group over the past year. Children are also susceptible to chronic consequences of COVID such as long COVID and multisystem inflammatory syndrome in children (MIS-C). Most studies demonstrate that 10-30% of children will develop chronic symptoms following COVID-19. These include complaints of brain fog, fatigue, trouble breathing, fever, headache, muscle and joint pains, abdominal pain, mood swings and even psychiatric disorders. Symptoms typically last from 4-8 weeks in children, with some reporting symptoms that persist for many months.
Second, children are increasingly recognized as vectors who can bring infection into the house, potentially transmitting infection to vulnerable household members. Finally, we have all seen the mayhem that results when one child in the classroom becomes infected with COVID and the other students get sent home to quarantine – across the U.S., more than 2000 schools have been affected this way.
We now have an extraordinarily effective vaccine with more than 90 percent efficacy at preventing symptomatic infection. Vaccinating children will boost our countrywide vaccination rate which is trailing many countries after an early start. Nevertheless, there are still many questions and concerns that parents have as the vaccine gets rolled out. I will address six of them here.
"Novel Vaccine Technology"
Even though this is a relatively new vaccine, the technology is not new. Scientists had worked on mRNA vaccines for decades prior to the COVID mRNA vaccine breakthrough. Furthermore, experience with the Pfizer COVID vaccine is rapidly growing. By now it has been more than a year and a half since the Pfizer trials began in March 2020, and more than 7 billion doses have already been administered globally, including in 13.7 million adolescents in the U.S. alone.
"Will This Vaccine Alter My Child's DNA?"
No. This is not how mRNA works. DNA is present in the cell's nucleus. The mRNA only stays in the outside cytoplasm, gets destroyed and never enters the inner sanctum of the nucleus. Furthermore, for the mRNA to be ever integrated into DNA, it requires a special enzyme called reverse transcriptase which humans don't have. Proteins (that look like the spike proteins on SARS-CoV-2) are made directly from this mRNA message without involvement of our DNA at any time. Pieces of spike proteins get displayed on the outside of our cells and our body makes protective antibodies that then protects us handily against the future real virus if it were ever to enter our (or our children's) bodies. Our children's DNA or genes can never be affected by an mRNA vaccine.
"Lack of Info on Long-Term Side Effects"
Unlike medications that are taken daily or periodically and can build up over time, the mRNA in the Pfizer vaccine is evanescent. It literally is just the messenger (that is what the "m" in mRNA stands for) and the messenger quickly disappears. mRNA is extremely fragile and easily inactivated – that's why we need to encase it in a special fatty bubble and store the vaccines at extremely cold temperatures. Our cells break down and destroy the mRNA within a few days after receiving the instructions to make the virus spike proteins. The presence of these fragments of the virus (note this is not "live" virus) prompts our immune system to generate protective antibodies to the real thing. Our bodies break down mRNA all the time in normal cellular processes – this is nothing new.
What the transience of the delivery system means is that most of the effects of the mRNA vaccines are expected to be more immediate (sore arm, redness at the site, fever, chills etc.), with no long-term side effects anticipated. A severe allergic response has been reported to occur in some generally within the first 15 minutes, is very rare, and everyone gets observed for that as part of standard vaccine administration. Even with the very uncommon complication of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining of the heart) seen primarily in young men under the age of 30 following mRNA vaccines, these typically happen within days to 2 weeks and many return to work or school in days. In the 70-year history of pediatric (and adult vaccines), dangerous complications happen in the first two months. There have been millions of adolescents as young as 12 years and thousands in the initial trial of children aged 5-11 who have already received the vaccine and are well beyond the two-month period of observation. There is no biological reason to believe that younger children will have a different long-term side effect profile compared to adolescents or adults.
"Small Sample Size in Kids and the Trial Design"
Although the Pfizer trial in children aged 5-11 was relatively small, it was big enough to give us statistical confidence in assessing safety and efficacy outcomes. Scientists spend a lot of time determining the right sample size of a study during the design phase. On one hand, you want to conduct the study efficiently so that resources are used in a cost-effective way and that you get a timely answer, especially in a fast-moving pandemic. On the other hand, you want to make sure you have enough sample size so that you can answer the question confidently as to whether the intervention works and whether there are adverse effects. The more profound the effect size of the intervention (in this case the vaccine), the fewer the numbers of children needed in the trials.
Statistics help investigators determine whether the results seen would have appeared by chance or not. In this case, the effect was real and impressive. Over 3,000 children around the world have received the vaccines through the trials alone with no serious side effects detected. The first press release reported that the immune response in children aged 5-11 was similar (at one-third the vaccine dose) to the response in the comparator group aged 16-25 years old. Extrapolating clinical efficacy results from immune response measurements ("immunobridging" study) would already have been acceptable if this was the only data. This is a standard trial design for many pediatric vaccines. Vaccines are first tested in the lab, followed by animals then adults. Only when deemed safe in adults and various regulatory bodies have signed off, do the pediatric vaccine trials commence.
Because children's immune systems and bodies are in a constant state of development, the vaccines must be right-sized. Investigators typically conduct "age de-escalation" studies in various age groups. The lowest dose is first tried so see if that is effective, then the dose is increased gradually as needed. Immune response is the easiest, safest and most efficient way to test the efficacy of pediatric vaccines. This is a typical size and design of a childhood vaccine seeking regulatory approval. There is no reason to think that the clinical efficacy would be any different in children vs. adults for a given antibody response, given the experience already in the remainder of the population, including older children and adolescents. Although this was primarily designed as an "immunobridging" study, the initial immunologic response data was followed by real clinical outcomes in this population. Reporting on the outcomes of 2,268 children in the randomized controlled trial, the vaccine was 90.7% effective at preventing symptomatic infection.
"Fear of Myocarditis"
Myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the lining of the heart) have been associated with receipt of the mRNA vaccines, particularly among male adolescents and young adults, typically within a few days after receiving the second dose. But this is very rare. For every million vaccine recipients, you would expect 41 cases in males, and 4 cases in females aged 12-29 years-old. The risk in older age groups is substantially lower. It is important to recognize that the risk of myocarditis associated with COVID is substantially higher. Patients present with new chest pain, shortness of breath, or palpitations after receiving an mRNA vaccine (more common after the second dose). But outcomes are good if associated with the vaccine. Most respond well to treatment and resolve symptoms within a week. There have been no deaths associated with vaccine-associated myocarditis.
In contrast, COVID-associated myocarditis has been associated with more severe cases as well as other complications including chronic symptoms of long COVID. The risk of myocarditis is likely related to vaccine dose, so the fact that one-third the dose of the vaccine will be used in the 5-11 year-olds is expected to correspond to a lower risk of myocarditis. At the lower dose given to younger kids, there has been a lower incidence of adverse effects reported compared to older children and adults who received the full dose. In addition, baseline rates of myocarditis not associated with vaccination are much lower in children ages 5-11 years than in older children, so the same may hold true for vaccine-associated myocarditis cases. This is because myocarditis is associated with sex hormones (particularly testosterone) that surge during puberty. In support of this, the incidence of vaccine-associated myocarditis is lower in 12–15-year-old boys, compared to those who were older than 16 years old. There were no cases of myocarditis reported in the experience to date of 5–11-year-old children in the trials, although the trial was too small to pick up on such a rare effect.
"Optimal Dose Spacing Interval: Longer Than 3 Weeks?"
There is a biologic basis for increasing the interval between vaccine doses in general. Priming the immune system with the first shot and then waiting gives the second shot a better chance of prompting a secondary immune reaction that results in a more durable response (with more T cell driven immune memory). One study from the U.K. showed that the antibody response in people over 80 was more than 3 times higher if they delayed the second dose to after 12 weeks for the Pfizer vaccine instead of the 3 weeks studied in trials. In a study of 503 British health care workers, there were twice as many neutralizing antibodies produced in a longer interval group (6-14 weeks) versus a shorter interval group (3-4 weeks) between doses. However, the safety and efficacy with longer intervals has not been evaluated in the pediatric or other COVID vaccine trials.
In the U.S., the C.D.C. reported that 88 percent of counties are at a "high" or "substantial" level of community transmission. Also, Europe is already experiencing a winter surge of infections that may predict more U.S. winter cases as international travel reopens. During a time of high community virus burden with a highly transmissible Delta variant, relying on one dose of vaccine for several more weeks until the second may leave many more susceptible to infection while waiting. One study from England showed that one dose of the Pfizer vaccine was only 33% protective against symptomatic Delta infection in contrast to 50% for the Alpha variant in adults. There has been no corollary information in children but we would expect less protection in general from one vaccine dose vs. two. This is a particularly important issue with the upcoming holiday season when an increased number of families will travel. Some countries such as the U.K. and Norway have proceeded with only offering older than 12 year-olds one dose of vaccine rather than two, but this was before the current European surge which may change the risk-benefit calculus. There are no plans to only offer one vaccine dose in the U.S. at this time. However a lower dose of the vaccine will likely be studied in the future for adolescents aged 12-15.
For parents worried about the potential risk of adverse effects of two doses of vaccines in their children, it is reasonable to wait 6-12 weeks for the second shot but it all depends on your risk-benefit calculus. There is biological plausibility to pursue this strategy. Although there is no pediatric-specific data to draw from, a longer interval may lengthen immune memory and potentially decrease the risk of myocarditis, particularly in boys. There may only be partial benefit in eliciting protective antibodies after one vaccine dose but only 2-4% of children are hospitalized with COVID once infected, with risk of severe illness increasing if they have comorbidities.
There are also some data indicating that 40% of children have already been exposed to infection naturally and may not need further protection after one shot. However, this percentage is likely a large overestimation given the way the data was collected. Using antibody tests to ascertain previous infection in children may be problematic for several reasons: uncertainty regarding duration of protection, variability in symptoms in children with most having very mild symptoms, and the lack of standardization of antibody tests in general. Overall, if the child has medical comorbidities such as diabetes, parents are planning to travel with their children, if local epidemiology shows increasing cases, and if there are elderly or immunocompromised individuals in the household, I would vaccinate children with two doses as per the original recommended schedule.
Bottom line: Given the time of the year and circulating Delta, I would probably stick with the recommended 3-week interval between doses for now for most children. But if parents choose a longer interval between the first and second dose for their children, I wouldn't worry too much about it. Better to be vaccinated - even if slowly, over time -- than not at all.
A startup aims to make medicines in space
Story by Big Think
On June 12, a SpaceX Falcon 9 rocket deployed 72 small satellites for customers — including the world’s first space factory.
The challenge: In 2019, pharma giant Merck revealed that an experiment on the International Space Station had shown how to make its blockbuster cancer drug Keytruda more stable. That meant it could now be administered via a shot rather than through an IV infusion.
The key to the discovery was the fact that particles behave differently when freed from the force of gravity — seeing how its drug crystalized in microgravity helped Merck figure out how to tweak its manufacturing process on Earth to produce the more stable version.
Microgravity research could potentially lead to many more discoveries like this one, or even the development of brand-new drugs, but ISS astronauts only have so much time for commercial experiments.
“There are many high-performance products that are only possible to make in zero-gravity, which is a manufacturing capability that cannot be replicated in any factory on Earth.”-- Will Bruey.
The only options for accessing microgravity (or free fall) outside of orbit, meanwhile, are parabolic airplane flights and drop towers, and those are only useful for experiments that require less than a minute in microgravity — Merck’s ISS experiment took 18 days.
The idea: In 2021, California startup Varda Space Industries announced its intention to build the world’s first space factory, to manufacture not only pharmaceuticals but other products that could benefit from being made in microgravity, such as semiconductors and fiber optic cables.
This factory would consist of a commercial satellite platform attached to two Varda-made modules. One module would contain equipment capable of autonomously manufacturing a product. The other would be a reentry capsule to bring the finished goods back to Earth.
“There are many high-performance products that are only possible to make in zero-gravity, which is a manufacturing capability that cannot be replicated in any factory on Earth,” said CEO Will Bruey, who’d previously developed and flown spacecraft for SpaceX.
“We have a team stacked with aerospace talent in the prime of their careers, focused on getting working hardware to orbit as quickly as possible,” he continued.
“[Pharmaceuticals] are the most valuable chemicals per unit mass. And they also have a large market on Earth.” -- Will Bruey, CEO of Varda Space.
What’s new? At the time, Varda said it planned to launch its first space factory in 2023, and, in what feels like a first for a space startup, it has actually hit that ambitious launch schedule.
“We have ACQUISITION OF SIGNAL,” the startup tweeted soon after the Falcon 9 launch on June 12. “The world’s first space factory’s solar panels have found the sun and it’s beginning to de-tumble.”
During the satellite’s first week in space, Varda will focus on testing its systems to make sure everything works as hoped. The second week will be dedicated to heating and cooling the old HIV-AIDS drug ritonavir repeatedly to study how its particles crystalize in microgravity.
After about a month in space, Varda will attempt to bring its first space factory back to Earth, sending it through the atmosphere at hypersonic speeds and then using a parachute system to safely land at the Department of Defense’s Utah Test and Training Range.
Looking ahead: Ultimately, Varda’s space factories could end up serving dual purposes as manufacturing facilities and hypersonic testbeds — the Air Force has already awarded the startup a contract to use its next reentry capsule to test hardware for hypersonic missiles.
But as for manufacturing other types of goods, Varda plans to stick with drugs for now.
“[Pharmaceuticals] are the most valuable chemicals per unit mass,” Bruey told CNN. “And they also have a large market on Earth.”
“You’re not going to see Varda do anything other than pharmaceuticals for the next minimum of six, seven years,” added Delian Asparouhov, Varda’s co-founder and president.
Genes that protect health with Dr. Nir Barzilai
In today’s podcast episode, I talk with Nir Barzilai, a geroscientist, which means he studies the biology of aging. Barzilai directs the Institute for Aging Research at the Albert Einstein College of Medicine.
My first question for Dr. Barzilai was: why do we age? And is there anything to be done about it? His answers were encouraging. We can’t live forever, but we have some control over the process, as he argues in his book, Age Later.
Dr. Barzilai told me that centenarians differ from the rest of us because they have unique gene mutations that help them stay healthy longer. For most of us, the words “gene mutations” spell trouble - we associate these words with cancer or neurodegenerative diseases, but apparently not all mutations are bad.
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Centenarians may have essentially won the genetic lottery, but that doesn’t mean the rest of us are predestined to have a specific lifespan and health span, or the amount of time spent living productively and enjoyably. “Aging is a mother of all diseases,” Dr. Barzilai told me. And as a disease, it can be targeted by therapeutics. Dr. Barzilai’s team is already running clinical trials on such therapeutics — and the results are promising.
More about Dr. Barzilai: He is scientific director of AFAR, American Federation for Aging Research. As part of his work, Dr. Barzilai studies families of centenarians and their genetics to learn how the rest of us can learn and benefit from their super-aging. He also organizing a clinical trial to test a specific drug that may slow aging.
Show Links
Age Later: Health Span, Life Span, and the New Science of Longevity https://www.amazon.com/Age-Later-Healthiest-Sharpest-Centenarians/dp/1250230853
American Federation for Aging Research https://www.afar.org
https://www.afar.org/nir-barzilai
https://www.einsteinmed.edu/faculty/484/nir-barzilai/
Metformin as a Tool to Target Aging
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5943638/
Benefits of Metformin in Attenuating the Hallmarks of Aging https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7347426/
The Longevity Genes Project https://www.einsteinmed.edu/centers/aging/longevity-genes-project/
Lina Zeldovich has written about science, medicine and technology for Popular Science, Smithsonian, National Geographic, Scientific American, Reader’s Digest, the New York Times and other major national and international publications. A Columbia J-School alumna, she has won several awards for her stories, including the ASJA Crisis Coverage Award for Covid reporting, and has been a contributing editor at Nautilus Magazine. In 2021, Zeldovich released her first book, The Other Dark Matter, published by the University of Chicago Press, about the science and business of turning waste into wealth and health. You can find her on http://linazeldovich.com/ and @linazeldovich.