It is exciting to be vaccinating people at the rates we are at – more than 150,000 doses were administered in Utah last week, and that number is only expected to increase. On April 1, all Utah adults are eligible to apply, but for some the decision is not so easy.
Children, pregnant women and those who have had COVID-19 may present different challenges. I want to explain why this is and what science says about vaccination options for these groups.
Vaccines for children
Teens aged 16 and over may receive the Pfizer vaccine, but not Moderna or Johnson & Johnson. For children under 16, we are still awaiting clinical trials.
As with everything COVID-19 and children, it is important not to think of children as a group, but as several different age categories. In many ways, adolescents who have gone through puberty appear to have similar results – albeit better than – other young adults, while younger children appear to have additional protective abilities that make symptomatic infection more unlikely.
So, for months, these companies have been testing their coronavirus vaccines on teenagers. Moderna’s “TeenCove” study, started in December, aims to study the impact of the vaccine on about 3,000 young people aged 12 to 18 years. Pfizer’s vaccine was first tested on people aged 16 and over, and the company fully enrolled a study in children aged 12 to 15 in January.
Biologists are very confident that the vaccine will work in essentially the same way in these teenagers and older people, but of course we need to study it to be sure. The results of these studies are scheduled to be released in “mid-year 2021”. It seems that researchers are trying to make conclusions before the 2021-22 school year, so June or July is a relatively safe bet.
And now, we are studying the vaccine in younger children as well. Moderna announced a Phase 2/3 study on Tuesday to test its vaccine in two different age groups: from six months to two years and from two years to 12 years. Researchers will test the vaccine on 6,750 children and experiment with different dosage sizes to see which is the most effective. In the younger set, they will give doses of one-quarter, half and full size, and in the older set, they will try medium and full doses. Pfizer has not yet started a similar study, but says it plans to this month.
When will we get the results of these experiments? “Just looking at the schedules, it’s probably more likely from late 2021 to early 2022 for younger children, but maybe a little faster than that,” Robert Frenck, director of the Vaccine Research Center at Children’s Hospital of Cincinnati and a principal investigator for Pfizer research, he told Bloomberg.
The Johnson & Johnson vaccine is interesting when it comes to children, not only because of the simplicity of a dose, but also because it uses an older vaccine technology. This means that vaccines of this type have already been used in young children, including for Ebola and RSV. Although Johnson & Johnson has not yet started a study with children under 12, it plans to do so.
Vaccines for pregnant women
The Centers for Disease Control and Prevention does not openly recommend that pregnant mothers be vaccinated, but they are also not saying that they should not. These federal officials say it is a “personal choice”. That’s because vaccines were not originally tested on pregnant women, but all signs so far have been positive.
Vaccination tests for Pfizer, Moderna and Johnson & Johnson generally excluded pregnant women, but some escaped – women who did not know they were pregnant or became pregnant after the test started. A total of 18 pregnant women were vaccinated “incidentally” as part of these studies and none had any adverse effects.
Most recently, the CDC tracked 30,000 pregnant women who chose to be vaccinated, including 1,800 who agreed to provide detailed descriptions of their results. As Harvard Medical School reports, “so far, pregnant women seem to have the same side effects of the vaccine as non-pregnant women. No vaccine-related miscarriage, stillbirth or premature delivery has been reported. “
More invasive tests have also been done on pregnant animals with coronavirus vaccines. Again, no red flags were raised.
In particular, it does not appear that the vaccine itself – be it the mRNA particles from the Pfizer / Moderna vaccines or the modified Johnson & Johnson vaccine virus – ends up reaching the placenta. These are eliminated by the body relatively quickly.
What seems to happen, however, is that after the body develops antibodies in response to the vaccine, those antibodies are shared with the baby. A Massachusetts General Hospital study that tested the umbilical cord blood of 10 newborns after their mothers were vaccinated found antibodies in all 10. A similar study in Israel found the same thing, but with 20 pairs of women / newborns born.
This is not a big surprise, it is the case with most vaccines. But it is basically the best scenario: newborns actually have a relatively high risk compared to COVID-19, and it seems that the mother’s vaccination can give antibodies to these babies without exposing them to the vaccine itself.
Meanwhile, Pfizer has a trial in progress with 4,000 pregnant women, with the first participants being medicated for about a month. After the test is over in a few months, I hope that the CDC will give the full endorsement.
Vaccines for people previously infected with COVID-19
Right now, in Utah, those who have been infected with COVID-19 in the past 90 days are being asked to wait to be vaccinated. The reasoning is simple: you already have the antibodies and they are strong, so save the dose for someone else.
That said, the Utah decree is a suggestion – if you really want to be vaccinated, despite being infected in the past 90 days, you can. It is a kind of selfish movement, but for sure.
Interestingly, studies show that those who have already been infected tend to have a stronger immune response at the first dose than those who have not yet received COVID-19.
And, in fact, there are already several studies that show that just one dose should be enough for the total protection of those who have already had the disease. These studies show a multiplication of 100x to 1000x in the levels of antibodies after the first dose, but no real change in the antibodies after receiving the second dose.
That makes sense. For COVID-19 “naive” individuals – people who have not been infected – the first dose teaches the body about the virus, and the second teaches the body that the virus is an ongoing threat. For those who have already been infected, the first dose works as a lesson. A second dose is overkill: “Well, here is this virus for the third time this year.”
Therefore, those who have had the coronavirus should definitely be vaccinated, but perhaps not several times. Still, the current CDC and Utah protocol is to give these people both doses, although the scientists who worked on the studies above have asked the CDC to change that. It takes too long for the CDC to change its mind, which is reasonable, although reasonable, but some other countries have already abandoned it at once.
If I had been infected previously, my approach would be “wait and see”. If I had tested positive in the past 90 days, I would have expected my dose so that someone at higher risk could get it. If more had passed, I would take my first dose as soon as possible and then use the next 21-28 days to look at the CDC page for changes to its protocol.
Andy Larsen is a data columnist. He is also one of the Utah Jazz writers for The Salt Lake Tribune. You can reach it at [email protected].